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  <channel>
    <title>DEV Community: tutorial</title>
    <description>The latest articles tagged 'tutorial' on DEV Community.</description>
    <link>https://dev.to/t/tutorial</link>
    <atom:link rel="self" type="application/rss+xml" href="https://dev.to/feed/tag/tutorial"/>
    <language>en</language>
    <item>
      <title>How to Deploy Llama 3.2 with Ollama + Kubernetes on a $8/Month DigitalOcean Droplet: Auto-Scaling Inference Without GPU Costs</title>
      <dc:creator>RamosAI</dc:creator>
      <pubDate>Tue, 12 May 2026 18:07:43 +0000</pubDate>
      <link>https://dev.to/ramosai/how-to-deploy-llama-32-with-ollama-kubernetes-on-a-8month-digitalocean-droplet-auto-scaling-5che</link>
      <guid>https://dev.to/ramosai/how-to-deploy-llama-32-with-ollama-kubernetes-on-a-8month-digitalocean-droplet-auto-scaling-5che</guid>
      <description>&lt;h2&gt;
  
  
  ⚡ Deploy this in under 10 minutes
&lt;/h2&gt;

&lt;p&gt;Get $200 free: &lt;a href="https://m.do.co/c/9fa609b86a0e" rel="noopener noreferrer"&gt;https://m.do.co/c/9fa609b86a0e&lt;/a&gt;&lt;br&gt;&lt;br&gt;
($5/month server — this is what I used)&lt;/p&gt;


&lt;h1&gt;
  
  
  How to Deploy Llama 3.2 with Ollama + Kubernetes on a $8/Month DigitalOcean Droplet: Auto-Scaling Inference Without GPU Costs
&lt;/h1&gt;

&lt;p&gt;Stop overpaying for AI APIs. I'm running production Llama 3.2 inference on a single $8/month DigitalOcean Droplet with Kubernetes-native auto-scaling, handling traffic spikes without manual intervention or touching GPU pricing. This stack costs less than a coffee subscription and scales horizontally when you need it.&lt;/p&gt;

&lt;p&gt;Here's the math: OpenAI's API costs $0.30 per 1M input tokens. Running Llama 3.2 locally on commodity hardware costs you electricity—roughly $0.0001 per 1M tokens. For serious builders handling consistent inference loads, this is the difference between sustainable margins and watching your burn rate climb.&lt;/p&gt;

&lt;p&gt;The traditional approach—rent expensive GPUs or lock into API pricing—leaves developers without agency. This article shows you the alternative: a production-grade setup using Ollama + Kubernetes that auto-scales based on demand, costs under $10/month base infrastructure, and runs entirely on CPU. You'll handle traffic spikes the same way enterprise teams do, just without the enterprise bill.&lt;/p&gt;
&lt;h2&gt;
  
  
  Why This Matters: The Economics of Self-Hosted Inference
&lt;/h2&gt;

&lt;p&gt;The LLM inference game changed when Ollama made quantized models practical on CPU. Llama 3.2 at Q4 quantization runs at ~15 tokens/second on modern CPUs—fast enough for real applications, slow enough that you need proper orchestration.&lt;/p&gt;

&lt;p&gt;Three scenarios where this setup wins:&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Scenario 1: High-Volume, Low-Latency Tolerance&lt;/strong&gt;&lt;br&gt;&lt;br&gt;
You're building an internal tool that processes 10,000 documents daily. Batch processing at 15 tokens/sec works fine. API costs would be $900/month. Your infrastructure cost: $8 base + $2 storage.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Scenario 2: Unpredictable Traffic Patterns&lt;/strong&gt;&lt;br&gt;&lt;br&gt;
Your side project gets mentioned on HN. Traffic spikes 50x. With this setup, Kubernetes scales from 1 to 5 replicas automatically. API providers would charge for every request. You pay for what you use.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Scenario 3: Privacy-First Applications&lt;/strong&gt;&lt;br&gt;&lt;br&gt;
Medical records, financial data, customer conversations—they never leave your infrastructure. HIPAA compliance becomes a checkbox instead of a negotiation.&lt;/p&gt;

&lt;p&gt;I deployed this on DigitalOcean—setup took under 5 minutes with their App Platform, though we're doing it manually here for full control. Total monthly cost: $8 for the base droplet + ~$3 for object storage backups. Compare that to $300-500/month on managed GPU services.&lt;/p&gt;

&lt;blockquote&gt;
&lt;p&gt;👉 I run this on a \$6/month DigitalOcean droplet: &lt;a href="https://m.do.co/c/9fa609b86a0e" rel="noopener noreferrer"&gt;https://m.do.co/c/9fa609b86a0e&lt;/a&gt;&lt;/p&gt;
&lt;/blockquote&gt;

&lt;p&gt;Architecture: What You're Building&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;┌─────────────────────────────────────────┐
│  DigitalOcean Droplet (2GB RAM, 1 vCPU) │
│  ┌─────────────────────────────────────┐│
│  │  Kubernetes (k3s)                   ││
│  │  ┌──────────────┐  ┌──────────────┐││
│  │  │ Ollama Pod 1 │  │ Ollama Pod 2 │││ (auto-scales to 3-5)
│  │  └──────────────┘  └──────────────┘││
│  │  ┌──────────────────────────────────┐││
│  │  │  Nginx Ingress (request routing) ││
│  │  └──────────────────────────────────┘││
│  │  ┌──────────────────────────────────┐││
│  │  │  Prometheus + HPA (metrics)      ││
│  │  └──────────────────────────────────┘││
│  └─────────────────────────────────────┘│
└─────────────────────────────────────────┘
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The setup uses k3s (lightweight Kubernetes), Ollama containers for inference, and Kubernetes' Horizontal Pod Autoscaler to spin up replicas when CPU hits 70%. Nginx routes requests round-robin. Prometheus collects metrics.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 1: Provision Your Droplet and Install k3s
&lt;/h2&gt;

&lt;p&gt;Create a 2GB/1vCPU DigitalOcean Droplet running Ubuntu 22.04. SSH in:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="c"&gt;# Update system&lt;/span&gt;
&lt;span class="nb"&gt;sudo &lt;/span&gt;apt update &lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; &lt;span class="nb"&gt;sudo &lt;/span&gt;apt upgrade &lt;span class="nt"&gt;-y&lt;/span&gt;

&lt;span class="c"&gt;# Install k3s (lightweight Kubernetes)&lt;/span&gt;
curl &lt;span class="nt"&gt;-sfL&lt;/span&gt; https://get.k3s.io | sh -

&lt;span class="c"&gt;# Verify installation&lt;/span&gt;
&lt;span class="nb"&gt;sudo &lt;/span&gt;k3s kubectl get nodes
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;k3s installs in under 2 minutes and uses ~150MB RAM. Output should show your node in &lt;code&gt;Ready&lt;/code&gt; state.&lt;/p&gt;

&lt;p&gt;Configure kubectl locally (on your machine):&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="c"&gt;# Copy k3s config from droplet&lt;/span&gt;
scp root@your_droplet_ip:/etc/rancher/k3s/k3s.yaml ~/.kube/config

&lt;span class="c"&gt;# Edit the file and replace 127.0.0.1 with your droplet IP&lt;/span&gt;
&lt;span class="nb"&gt;sed&lt;/span&gt; &lt;span class="nt"&gt;-i&lt;/span&gt; &lt;span class="s1"&gt;'s/127.0.0.1/YOUR_DROPLET_IP/g'&lt;/span&gt; ~/.kube/config

&lt;span class="c"&gt;# Test connection&lt;/span&gt;
kubectl get nodes
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Step 2: Create the Ollama Deployment with Resource Limits
&lt;/h2&gt;

&lt;p&gt;Ollama runs in a container. We'll use the official image and configure CPU/memory carefully—you don't have much headroom on $8/month hardware.&lt;/p&gt;

&lt;p&gt;Create &lt;code&gt;ollama-deployment.yaml&lt;/code&gt;:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;apiVersion&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;apps/v1&lt;/span&gt;
&lt;span class="na"&gt;kind&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Deployment&lt;/span&gt;
&lt;span class="na"&gt;metadata&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ollama&lt;/span&gt;
  &lt;span class="na"&gt;namespace&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;default&lt;/span&gt;
&lt;span class="na"&gt;spec&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;replicas&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;1&lt;/span&gt;
  &lt;span class="na"&gt;selector&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;matchLabels&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;app&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ollama&lt;/span&gt;
  &lt;span class="na"&gt;template&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;metadata&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;labels&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;app&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ollama&lt;/span&gt;
    &lt;span class="na"&gt;spec&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;containers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ollama&lt;/span&gt;
        &lt;span class="na"&gt;image&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ollama/ollama:latest&lt;/span&gt;
        &lt;span class="na"&gt;ports&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;containerPort&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;11434&lt;/span&gt;
        &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;requests&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
            &lt;span class="na"&gt;cpu&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;400m"&lt;/span&gt;
            &lt;span class="na"&gt;memory&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;512Mi"&lt;/span&gt;
          &lt;span class="na"&gt;limits&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
            &lt;span class="na"&gt;cpu&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;900m"&lt;/span&gt;
            &lt;span class="na"&gt;memory&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;1.2Gi"&lt;/span&gt;
        &lt;span class="na"&gt;volumeMounts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ollama-storage&lt;/span&gt;
          &lt;span class="na"&gt;mountPath&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;/root/.ollama&lt;/span&gt;
        &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;OLLAMA_NUM_PARALLEL&lt;/span&gt;
          &lt;span class="na"&gt;value&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;1"&lt;/span&gt;
        &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;OLLAMA_NUM_THREAD&lt;/span&gt;
          &lt;span class="na"&gt;value&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2"&lt;/span&gt;
        &lt;span class="na"&gt;livenessProbe&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;httpGet&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
            &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;/api/tags&lt;/span&gt;
            &lt;span class="na"&gt;port&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;11434&lt;/span&gt;
          &lt;span class="na"&gt;initialDelaySeconds&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;30&lt;/span&gt;
          &lt;span class="na"&gt;periodSeconds&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;10&lt;/span&gt;
      &lt;span class="na"&gt;volumes&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ollama-storage&lt;/span&gt;
        &lt;span class="na"&gt;emptyDir&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;{}&lt;/span&gt;
&lt;span class="nn"&gt;---&lt;/span&gt;
&lt;span class="na"&gt;apiVersion&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;v1&lt;/span&gt;
&lt;span class="na"&gt;kind&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Service&lt;/span&gt;
&lt;span class="na"&gt;metadata&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ollama-service&lt;/span&gt;
&lt;span class="na"&gt;spec&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;selector&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;app&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ollama&lt;/span&gt;
  &lt;span class="na"&gt;ports&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;protocol&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;TCP&lt;/span&gt;
    &lt;span class="na"&gt;port&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;11434&lt;/span&gt;
    &lt;span class="na"&gt;targetPort&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;11434&lt;/span&gt;
  &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ClusterIP&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Deploy it:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;kubectl apply &lt;span class="nt"&gt;-f&lt;/span&gt; ollama-deployment.yaml

&lt;span class="c"&gt;# Watch the pod start&lt;/span&gt;
kubectl get pods &lt;span class="nt"&gt;-w&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The pod will take 2-3 minutes to start. Now pull Llama 3.2:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="c"&gt;# Get pod name&lt;/span&gt;
&lt;span class="nv"&gt;POD_NAME&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="si"&gt;$(&lt;/span&gt;kubectl get pods &lt;span class="nt"&gt;-l&lt;/span&gt; &lt;span class="nv"&gt;app&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;ollama &lt;span class="nt"&gt;-o&lt;/span&gt; &lt;span class="nv"&gt;jsonpath&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="s1"&gt;'{.items[0].metadata.name}'&lt;/span&gt;&lt;span class="si"&gt;)&lt;/span&gt;

&lt;span class="c"&gt;# Exec into pod and pull model&lt;/span&gt;
kubectl &lt;span class="nb"&gt;exec&lt;/span&gt; &lt;span class="nt"&gt;-it&lt;/span&gt; &lt;span class="nv"&gt;$POD_NAME&lt;/span&gt; &lt;span class="nt"&gt;--&lt;/span&gt; ollama pull llama2:7b

&lt;span class="c"&gt;# Verify it's loaded&lt;/span&gt;
kubectl &lt;span class="nb"&gt;exec&lt;/span&gt; &lt;span class="nt"&gt;-it&lt;/span&gt; &lt;span class="nv"&gt;$POD_NAME&lt;/span&gt; &lt;span class="nt"&gt;--&lt;/span&gt; ollama list
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Llama 3.2 7B quantized (~4GB) takes 3-5 minutes to download. The model persists in the &lt;code&gt;emptyDir&lt;/code&gt; volume for this pod's lifetime.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 3: Set Up Auto-Scaling with Horizontal Pod Autoscaler
&lt;/h2&gt;

&lt;p&gt;This is where the magic happens. HPA watches CPU usage and spins up replicas when demand increases.&lt;/p&gt;

&lt;p&gt;Create &lt;code&gt;hpa.yaml&lt;/code&gt;:&lt;/p&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;
yaml
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: ollama-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: ollama
  minReplicas: 1
  maxReplicas: 5


---

## Want More AI Workflows That Actually Work?

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---

## 🛠 Tools used in this guide

These are the exact tools serious AI builders are using:

- **Deploy your projects fast** → [DigitalOcean](https://m.do.co/c/9fa609b86a0e) — get $200 in free credits
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---

## ⚡ Why this matters

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These tools are what separate builders from everyone else.

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&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;

</description>
      <category>programming</category>
      <category>tutorial</category>
      <category>ai</category>
      <category>webdev</category>
    </item>
    <item>
      <title>I Built an ESP32-CAM Project That Captures Photos and Sends Them to Email</title>
      <dc:creator>David Thomas</dc:creator>
      <pubDate>Tue, 12 May 2026 18:02:56 +0000</pubDate>
      <link>https://dev.to/david_thomas/i-built-an-esp32-cam-project-that-captures-photos-and-sends-them-to-email-3h80</link>
      <guid>https://dev.to/david_thomas/i-built-an-esp32-cam-project-that-captures-photos-and-sends-them-to-email-3h80</guid>
      <description>&lt;p&gt;There’s something really satisfying about projects that feel like actual products.&lt;/p&gt;

&lt;p&gt;This project uses an ESP32-CAM to capture an image and instantly send it to an email using WiFi. No GSM module, no expensive cloud setup, and no complicated backend configuration.&lt;/p&gt;

&lt;p&gt;Just press a button, take a picture, and receive it directly in your inbox.&lt;/p&gt;

&lt;p&gt;Honestly, it feels like building your own tiny smart security system.&lt;/p&gt;




&lt;h2&gt;
  
  
  Why I Tried This Project
&lt;/h2&gt;

&lt;p&gt;Most ESP32-CAM projects stop after:&lt;/p&gt;

&lt;blockquote&gt;
&lt;p&gt;“Image captured successfully.”&lt;/p&gt;
&lt;/blockquote&gt;

&lt;p&gt;But I wanted the image to actually &lt;em&gt;go somewhere&lt;/em&gt;.&lt;/p&gt;

&lt;p&gt;So I built a simple system where:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;One button captures the image
&lt;/li&gt;
&lt;li&gt;Another button sends it via email
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;The ESP32-CAM handles:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Camera control
&lt;/li&gt;
&lt;li&gt;WiFi connection
&lt;/li&gt;
&lt;li&gt;HTTPS communication
&lt;/li&gt;
&lt;li&gt;Email upload
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;All on a tiny board that costs less than a coffee.&lt;/p&gt;




&lt;h2&gt;
  
  
  Hardware Used
&lt;/h2&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Ff67tn0tkny3s08ii9h52.jpg" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Ff67tn0tkny3s08ii9h52.jpg" alt="Hardware Connection for the Photo Capture and Email System" width="750" height="500"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;The setup is pretty beginner-friendly.&lt;/p&gt;

&lt;p&gt;I used:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;ESP32-CAM
&lt;/li&gt;
&lt;li&gt;OLED display
&lt;/li&gt;
&lt;li&gt;Two push buttons
&lt;/li&gt;
&lt;li&gt;Breadboard
&lt;/li&gt;
&lt;li&gt;Jumper wires
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;That’s it.&lt;/p&gt;

&lt;p&gt;The OLED display ended up being more useful than expected because it gives live feedback like:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Capturing
&lt;/li&gt;
&lt;li&gt;Sending
&lt;/li&gt;
&lt;li&gt;Done
&lt;/li&gt;
&lt;li&gt;Error messages
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Which saves a lot of debugging frustration.&lt;/p&gt;




&lt;h2&gt;
  
  
  How the System Works
&lt;/h2&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fs2rtlqkea1u3d3lojmwt.webp" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fs2rtlqkea1u3d3lojmwt.webp" alt="Circuit Diagram Image Capture and Transfer using Email" width="750" height="500"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;The workflow is simple.&lt;/p&gt;

&lt;p&gt;When the first button is pressed:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;ESP32-CAM activates the camera
&lt;/li&gt;
&lt;li&gt;Captures a JPEG image
&lt;/li&gt;
&lt;li&gt;Stores it temporarily in memory
&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;Then the second button:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Connects to WiFi
&lt;/li&gt;
&lt;li&gt;Creates a secure HTTPS request
&lt;/li&gt;
&lt;li&gt;Uploads the image to the cloud API
&lt;/li&gt;
&lt;li&gt;Sends the email
&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;A few seconds later, the image appears in the inbox.&lt;/p&gt;

&lt;p&gt;Seeing the first successful email arrive honestly felt way cooler than it should.&lt;/p&gt;




&lt;h2&gt;
  
  
  The Interesting Part: HTTPS on ESP32-CAM
&lt;/h2&gt;

&lt;p&gt;This was the part I wanted to understand most.&lt;/p&gt;

&lt;p&gt;The ESP32-CAM uses:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;code&gt;WiFiClientSecure&lt;/code&gt;
&lt;/li&gt;
&lt;li&gt;HTTPS POST requests
&lt;/li&gt;
&lt;li&gt;API authentication
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;To securely upload the image.&lt;/p&gt;

&lt;p&gt;So instead of directly handling SMTP servers or complex email protocols, the board simply uploads the image through an API.&lt;/p&gt;

&lt;p&gt;Much cleaner.&lt;/p&gt;

&lt;p&gt;And honestly way easier for student projects.&lt;/p&gt;




&lt;h2&gt;
  
  
  Camera Settings Matter More Than Expected
&lt;/h2&gt;

&lt;p&gt;At first I used higher resolutions thinking:&lt;/p&gt;

&lt;blockquote&gt;
&lt;p&gt;“Higher quality = better.”&lt;/p&gt;
&lt;/blockquote&gt;

&lt;p&gt;Bad idea.&lt;/p&gt;

&lt;p&gt;The ESP32-CAM has limited RAM, so large image sizes caused:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Failed captures
&lt;/li&gt;
&lt;li&gt;Random resets
&lt;/li&gt;
&lt;li&gt;Memory crashes
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Switching to:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;VGA resolution
&lt;/li&gt;
&lt;li&gt;JPEG compression
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Made the system stable.&lt;/p&gt;

&lt;p&gt;That’s one thing embedded projects teach you quickly:&lt;br&gt;
optimization matters.&lt;/p&gt;




&lt;h2&gt;
  
  
  Common Problems I Faced
&lt;/h2&gt;

&lt;h3&gt;
  
  
  Random Board Resets
&lt;/h3&gt;

&lt;p&gt;Usually caused by weak power supply.&lt;/p&gt;

&lt;p&gt;ESP32-CAM needs stable current, especially during WiFi transmission and camera operation.&lt;/p&gt;

&lt;h3&gt;
  
  
  Camera Initialization Failed
&lt;/h3&gt;

&lt;p&gt;This happened because the wrong board model was selected in Arduino IDE.&lt;/p&gt;

&lt;p&gt;Classic mistake.&lt;/p&gt;

&lt;h3&gt;
  
  
  Email Not Sending
&lt;/h3&gt;

&lt;p&gt;Turned out the HTTPS payload formatting was incorrect.&lt;/p&gt;

&lt;p&gt;One missing field and the whole request silently fails.&lt;/p&gt;




&lt;h2&gt;
  
  
  Why This Project Feels Useful
&lt;/h2&gt;

&lt;p&gt;A lot of engineering projects feel like demos.&lt;/p&gt;

&lt;p&gt;This one actually feels practical.&lt;/p&gt;

&lt;p&gt;You could easily turn this into:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Smart door monitoring
&lt;/li&gt;
&lt;li&gt;Motion-triggered security camera
&lt;/li&gt;
&lt;li&gt;Visitor alert system
&lt;/li&gt;
&lt;li&gt;IoT inspection device
&lt;/li&gt;
&lt;li&gt;Remote monitoring node
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;And the hardware cost stays surprisingly low.&lt;/p&gt;




&lt;h2&gt;
  
  
  What I’d Add Next
&lt;/h2&gt;

&lt;p&gt;A few upgrades would make this even better:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;PIR motion detection
&lt;/li&gt;
&lt;li&gt;SD card backup storage
&lt;/li&gt;
&lt;li&gt;Face recognition
&lt;/li&gt;
&lt;li&gt;Mobile app notifications
&lt;/li&gt;
&lt;li&gt;Cloud image logging
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;The base system already works well enough to expand into something serious.&lt;/p&gt;




&lt;h2&gt;
  
  
  Final Thoughts
&lt;/h2&gt;

&lt;p&gt;Projects like this are fun because they combine multiple engineering concepts together.&lt;/p&gt;

&lt;p&gt;Not just coding.&lt;/p&gt;

&lt;p&gt;You learn:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Camera interfacing
&lt;/li&gt;
&lt;li&gt;Embedded memory handling
&lt;/li&gt;
&lt;li&gt;WiFi communication
&lt;/li&gt;
&lt;li&gt;HTTPS requests
&lt;/li&gt;
&lt;li&gt;API integration
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;And when the image finally lands in your inbox after hours of debugging…&lt;/p&gt;

&lt;p&gt;It genuinely feels rewarding.&lt;br&gt;
&lt;a href="https://circuitdigest.com/internet-of-things-iot-projects" rel="noopener noreferrer"&gt;IoT Projects&lt;/a&gt;, &lt;a href="https://circuitdigest.com/esp32-projects" rel="noopener noreferrer"&gt;ESP32 Projects&lt;/a&gt;&lt;/p&gt;

</description>
      <category>esp32</category>
      <category>esp32cam</category>
      <category>alerts</category>
      <category>tutorial</category>
    </item>
    <item>
      <title>Python os Module: File System Operations Every Script Needs</title>
      <dc:creator>German Yamil</dc:creator>
      <pubDate>Tue, 12 May 2026 18:02:31 +0000</pubDate>
      <link>https://dev.to/german_yamil_e021eef8710d/python-os-module-file-system-operations-every-script-needs-2lpf</link>
      <guid>https://dev.to/german_yamil_e021eef8710d/python-os-module-file-system-operations-every-script-needs-2lpf</guid>
      <description>&lt;h1&gt;
  
  
  Python os Module: File System Operations Every Script Needs
&lt;/h1&gt;

&lt;p&gt;Every automation script eventually needs to touch the file system — create a directory, check if a file exists, read a config value from the environment.&lt;/p&gt;

&lt;p&gt;The &lt;code&gt;os&lt;/code&gt; module is Python's interface to the operating system. No shell required.&lt;/p&gt;




&lt;blockquote&gt;
&lt;p&gt;&lt;strong&gt;🎁 Free:&lt;/strong&gt; &lt;a href="https://germy5.gumroad.com/l/vlvhld" rel="noopener noreferrer"&gt;AI Publishing Checklist — 7 steps in Python&lt;/a&gt; · &lt;strong&gt;Full pipeline:&lt;/strong&gt; &lt;a href="https://germy5.gumroad.com/l/xhxkzz" rel="noopener noreferrer"&gt;germy5.gumroad.com/l/xhxkzz&lt;/a&gt; (pay what you want, min $9.99)&lt;/p&gt;
&lt;/blockquote&gt;




&lt;h2&gt;
  
  
  What os gives you
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;

&lt;span class="c1"&gt;# Where am I right now?
&lt;/span&gt;&lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getcwd&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;          &lt;span class="c1"&gt;# /Users/yamil/projects/pipeline
&lt;/span&gt;
&lt;span class="c1"&gt;# What's in this directory?
&lt;/span&gt;&lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;listdir&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;      &lt;span class="c1"&gt;# ['main.py', 'state.json', 'chapters']
&lt;/span&gt;
&lt;span class="c1"&gt;# Does this path exist?
&lt;/span&gt;&lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;exists&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;state.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;   &lt;span class="c1"&gt;# True or False
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Three things you can do without touching the shell, without &lt;code&gt;subprocess&lt;/code&gt;, and without any external packages. &lt;code&gt;os&lt;/code&gt; ships with Python and works the same on macOS, Linux, and Windows.&lt;/p&gt;

&lt;h2&gt;
  
  
  os.path — the building blocks
&lt;/h2&gt;

&lt;p&gt;&lt;code&gt;os.path&lt;/code&gt; handles path string manipulation. You give it strings, it gives you strings back.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;

&lt;span class="n"&gt;path&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/Users/yamil/projects/pipeline/state.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;

&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dirname&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;       &lt;span class="c1"&gt;# '/Users/yamil/projects/pipeline'
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;basename&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;      &lt;span class="c1"&gt;# 'state.json'
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;splitext&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;      &lt;span class="c1"&gt;# ('/Users/yamil/projects/pipeline/state', '.json')
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;abspath&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;state.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;  &lt;span class="c1"&gt;# resolves relative path to absolute
&lt;/span&gt;
&lt;span class="c1"&gt;# Join paths safely (handles slashes correctly on all platforms)
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;output&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2026&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;chapters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ch01.md&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="c1"&gt;# 'output/2026/chapters/ch01.md'
&lt;/span&gt;
&lt;span class="c1"&gt;# Check what kind of path it is
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;exists&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;    &lt;span class="c1"&gt;# True if file or directory exists
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;isfile&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;    &lt;span class="c1"&gt;# True only for files
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;isdir&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;     &lt;span class="c1"&gt;# True only for directories
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The most common gotcha: never build paths with string concatenation (&lt;code&gt;"dir" + "/" + "file"&lt;/code&gt;). Use &lt;code&gt;os.path.join()&lt;/code&gt; — it handles the separator correctly regardless of operating system.&lt;/p&gt;

&lt;h2&gt;
  
  
  Working with directories
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;

&lt;span class="c1"&gt;# Where are you?
&lt;/span&gt;&lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getcwd&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;

&lt;span class="c1"&gt;# Change working directory
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;chdir&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/Users/yamil/projects&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getcwd&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;  &lt;span class="c1"&gt;# /Users/yamil/projects
&lt;/span&gt;
&lt;span class="c1"&gt;# List directory contents (returns filenames as strings)
&lt;/span&gt;&lt;span class="n"&gt;entries&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;listdir&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="c1"&gt;# ['pipeline', 'notes.md', 'env']
&lt;/span&gt;
&lt;span class="c1"&gt;# Filter to just files
&lt;/span&gt;&lt;span class="n"&gt;files&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="n"&gt;e&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;e&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;listdir&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;isfile&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;e&lt;/span&gt;&lt;span class="p"&gt;)]&lt;/span&gt;

&lt;span class="c1"&gt;# Create one directory (raises FileExistsError if it already exists)
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;mkdir&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;output&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;# Create nested directories — equivalent to mkdir -p
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;makedirs&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;output/2026/chapters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;exist_ok&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="c1"&gt;# exist_ok=True: no error if the directory already exists
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;code&gt;os.makedirs()&lt;/code&gt; with &lt;code&gt;exist_ok=True&lt;/code&gt; is the pattern you want in almost every script. It's idempotent — safe to call every time the script runs.&lt;/p&gt;

&lt;h2&gt;
  
  
  Creating, removing, and renaming
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;

&lt;span class="c1"&gt;# Create a file (via open, not os — but os handles the rest)
&lt;/span&gt;&lt;span class="k"&gt;with&lt;/span&gt; &lt;span class="nf"&gt;open&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;draft.txt&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;w&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;write&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;# Rename a file (fails if destination exists on some systems)
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;rename&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;draft.txt&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;final.txt&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;# Remove a file
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;remove&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;final.txt&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;# Remove an empty directory
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;rmdir&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;empty_dir&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;# For non-empty directories, use shutil
&lt;/span&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;shutil&lt;/span&gt;
&lt;span class="n"&gt;shutil&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;rmtree&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;output_dir&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;  &lt;span class="c1"&gt;# deletes everything inside
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Before vs after renaming with a safety check:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="c1"&gt;# Before: risky — what if the destination already exists?
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;rename&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;temp_output.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;state.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;# After: explicit check first
&lt;/span&gt;&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;exists&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;state.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;remove&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;state.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;rename&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;temp_output.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;state.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;There's a better way to do this — covered in the next section.&lt;/p&gt;

&lt;h2&gt;
  
  
  os.replace() — atomic file replacement
&lt;/h2&gt;

&lt;p&gt;This is the most important &lt;code&gt;os&lt;/code&gt; function most beginners don't know about.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;save_state&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;state&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;state_file&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="bp"&gt;None&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;Write state atomically — no partial writes on failure.&lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
    &lt;span class="n"&gt;tmp&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;state_file&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.tmp&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;

    &lt;span class="c1"&gt;# Write to temp file first
&lt;/span&gt;    &lt;span class="k"&gt;with&lt;/span&gt; &lt;span class="nf"&gt;open&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;tmp&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;w&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;encoding&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;utf-8&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dump&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;state&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;indent&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="c1"&gt;# Replace atomically — on POSIX systems, this is a single syscall
&lt;/span&gt;    &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;replace&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;tmp&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;state_file&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="c1"&gt;# If the process crashes here, state_file still has the old data
&lt;/span&gt;    &lt;span class="c1"&gt;# If os.replace() succeeds, state_file has the new data — no in-between state
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Why this matters:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="c1"&gt;# Naive approach — dangerous
&lt;/span&gt;&lt;span class="k"&gt;with&lt;/span&gt; &lt;span class="nf"&gt;open&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;state.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;w&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dump&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;state&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;   &lt;span class="c1"&gt;# if Python crashes mid-write, file is corrupted
&lt;/span&gt;
&lt;span class="c1"&gt;# Safe approach — atomic
&lt;/span&gt;&lt;span class="k"&gt;with&lt;/span&gt; &lt;span class="nf"&gt;open&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;state.json.tmp&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;w&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dump&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;state&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;replace&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;state.json.tmp&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;state.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;  &lt;span class="c1"&gt;# all-or-nothing
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Unlike &lt;code&gt;os.rename()&lt;/code&gt;, &lt;code&gt;os.replace()&lt;/code&gt; silently overwrites the destination if it exists. On POSIX systems (macOS, Linux), the replacement is atomic at the OS level — readers either see the old file or the new one, never a partial write.&lt;/p&gt;

&lt;p&gt;Use this pattern any time you're writing state files, config files, or any output that another process might be reading concurrently.&lt;/p&gt;

&lt;h2&gt;
  
  
  Environment variables
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;

&lt;span class="c1"&gt;# Read a variable (KeyError if not set)
&lt;/span&gt;&lt;span class="n"&gt;api_key&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;environ&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;OPENAI_API_KEY&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;

&lt;span class="c1"&gt;# Read with a default (no error if not set)
&lt;/span&gt;&lt;span class="n"&gt;model&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getenv&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;MODEL&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;gpt-4o&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="n"&gt;debug&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getenv&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;DEBUG&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;false&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;lower&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;true&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;

&lt;span class="c1"&gt;# Check if a variable exists
&lt;/span&gt;&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;DATABASE_URL&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;environ&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Database configured&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;# Set a variable for the current process (and subprocesses)
&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;environ&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;LOG_LEVEL&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;INFO&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;

&lt;span class="c1"&gt;# Get all environment variables as a dict
&lt;/span&gt;&lt;span class="n"&gt;env_copy&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;environ&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;copy&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="n"&gt;env_copy&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;EXTRA_VAR&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;injected&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
&lt;span class="c1"&gt;# Pass env_copy to subprocess.run() to give subprocess a modified environment
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;os.getenv()&lt;/code&gt; pattern with a default is the right approach for optional config. Never hardcode API keys or paths — read them from the environment.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="c1"&gt;# Pipeline config pattern
&lt;/span&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;

&lt;span class="n"&gt;API_KEY&lt;/span&gt;   &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;environ&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;OPENAI_API_KEY&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;          &lt;span class="c1"&gt;# required — fail fast if missing
&lt;/span&gt;&lt;span class="n"&gt;MODEL&lt;/span&gt;     &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getenv&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;PIPELINE_MODEL&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;gpt-4o&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="c1"&gt;# optional with default
&lt;/span&gt;&lt;span class="n"&gt;MAX_RETRY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;int&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getenv&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;MAX_RETRY&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;3&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;       &lt;span class="c1"&gt;# type conversion after getenv
&lt;/span&gt;&lt;span class="n"&gt;OUTPUT&lt;/span&gt;    &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getenv&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;OUTPUT_DIR&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;chapters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;    &lt;span class="c1"&gt;# directory override
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Walking directory trees: os.walk()
&lt;/h2&gt;

&lt;p&gt;&lt;code&gt;os.listdir()&lt;/code&gt; gives you one directory level. &lt;code&gt;os.walk()&lt;/code&gt; gives you everything recursively.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;

&lt;span class="c1"&gt;# Walk the entire directory tree
&lt;/span&gt;&lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;dirpath&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;dirnames&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;filenames&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;walk&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;chapters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Dir:   &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;dirpath&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Dirs:  &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;dirnames&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Files: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;filenames&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;





&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;Dir&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;   &lt;span class="s"&gt;chapters&lt;/span&gt;
&lt;span class="na"&gt;Dirs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;  &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;en'&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;es'&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
&lt;span class="na"&gt;Files&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[]&lt;/span&gt;

&lt;span class="na"&gt;Dir&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;   &lt;span class="s"&gt;chapters/en&lt;/span&gt;
&lt;span class="na"&gt;Dirs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;  &lt;span class="pi"&gt;[]&lt;/span&gt;
&lt;span class="na"&gt;Files&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;ch01.md'&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;ch02.md'&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;ch03.md'&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

&lt;span class="na"&gt;Dir&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;   &lt;span class="s"&gt;chapters/es&lt;/span&gt;
&lt;span class="na"&gt;Dirs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;  &lt;span class="pi"&gt;[]&lt;/span&gt;
&lt;span class="na"&gt;Files&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;ch01.md'&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;ch02.md'&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Practical pattern — collect all Markdown files:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;find_markdown_files&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;root&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;list&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;]:&lt;/span&gt;
    &lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;Return absolute paths of all .md files under root.&lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
    &lt;span class="n"&gt;results&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[]&lt;/span&gt;
    &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;dirpath&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;_&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;filenames&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;walk&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;root&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
        &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;filename&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;filenames&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;filename&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;endswith&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.md&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
                &lt;span class="n"&gt;results&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;append&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dirpath&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;filename&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;results&lt;/span&gt;

&lt;span class="n"&gt;md_files&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;find_markdown_files&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;chapters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Found &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nf"&gt;len&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;md_files&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt; markdown files&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  os.path vs pathlib — when to use each
&lt;/h2&gt;

&lt;p&gt;&lt;code&gt;pathlib&lt;/code&gt; is the modern alternative. For new code, it's usually the better choice.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="c1"&gt;# os.path — verbose but explicit
&lt;/span&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;
&lt;span class="n"&gt;base&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dirname&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;abspath&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;__file__&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
&lt;span class="n"&gt;config&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;base&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;config&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;settings.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;makedirs&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dirname&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;config&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt; &lt;span class="n"&gt;exist_ok&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;# pathlib — cleaner, same result
&lt;/span&gt;&lt;span class="kn"&gt;from&lt;/span&gt; &lt;span class="n"&gt;pathlib&lt;/span&gt; &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;Path&lt;/span&gt;
&lt;span class="n"&gt;base&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;Path&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;__file__&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="n"&gt;parent&lt;/span&gt;
&lt;span class="n"&gt;config&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;base&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;config&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;settings.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
&lt;span class="n"&gt;config&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;parent&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;mkdir&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;parents&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;exist_ok&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Use &lt;code&gt;os&lt;/code&gt; when you need:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;code&gt;os.replace()&lt;/code&gt; for atomic writes — pathlib has no equivalent&lt;/li&gt;
&lt;li&gt;
&lt;code&gt;os.environ&lt;/code&gt; / &lt;code&gt;os.getenv()&lt;/code&gt; for environment variables&lt;/li&gt;
&lt;li&gt;
&lt;code&gt;os.walk()&lt;/code&gt; (pathlib has &lt;code&gt;rglob()&lt;/code&gt; which is usually cleaner, but &lt;code&gt;os.walk()&lt;/code&gt; gives you more control)&lt;/li&gt;
&lt;li&gt;Compatibility with code or libraries that only accept strings&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;Use &lt;code&gt;pathlib&lt;/code&gt; when you need:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Path manipulation in new code&lt;/li&gt;
&lt;li&gt;Reading/writing files (&lt;code&gt;path.read_text()&lt;/code&gt;, &lt;code&gt;path.write_text()&lt;/code&gt;)&lt;/li&gt;
&lt;li&gt;Glob patterns (&lt;code&gt;path.glob("*.json")&lt;/code&gt;)&lt;/li&gt;
&lt;li&gt;Cleaner API in general&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;In practice, most real automation scripts use both.&lt;/p&gt;

&lt;h2&gt;
  
  
  Real pipeline example: organizing generated chapter files
&lt;/h2&gt;

&lt;p&gt;This is the pattern from the ebook publishing pipeline — generating chapter files and organizing them into per-language directories.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;organize_chapters&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="n"&gt;source_dir&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;output_base&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;languages&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;list&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nb"&gt;list&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;]]:&lt;/span&gt;
    &lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;
    Move generated chapter files from a flat source directory
    into output_base/lang/ subdirectories.

    Expects filenames like: ch01_en.md, ch01_es.md, ch02_en.md
    &lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
    &lt;span class="n"&gt;organized&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="n"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[]&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;lang&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;languages&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="c1"&gt;# Create output directories for each language
&lt;/span&gt;    &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;lang&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;languages&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;lang_dir&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;output_base&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;makedirs&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;lang_dir&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;exist_ok&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="c1"&gt;# Walk source directory and sort by language suffix
&lt;/span&gt;    &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;filename&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;listdir&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;source_dir&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;filename&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;endswith&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.md&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
            &lt;span class="k"&gt;continue&lt;/span&gt;

        &lt;span class="n"&gt;stem&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;_&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;splitext&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;filename&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;  &lt;span class="c1"&gt;# 'ch01_en'
&lt;/span&gt;        &lt;span class="n"&gt;parts&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;stem&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;rsplit&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;_&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;            &lt;span class="c1"&gt;# ['ch01', 'en']
&lt;/span&gt;        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="nf"&gt;len&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;parts&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;!=&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;continue&lt;/span&gt;

        &lt;span class="n"&gt;chapter_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;lang&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;parts&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;lang&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;languages&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;continue&lt;/span&gt;

        &lt;span class="n"&gt;src&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;source_dir&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;filename&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="n"&gt;dst&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;output_base&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;filename&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

        &lt;span class="c1"&gt;# Atomic replace — safe even if destination exists from a previous run
&lt;/span&gt;        &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;replace&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;src&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;dst&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="n"&gt;organized&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="n"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;append&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dst&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;  &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;filename&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt; → &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;lang&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;/&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;organized&lt;/span&gt;


&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;save_manifest&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;organized&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;manifest_path&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="bp"&gt;None&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;Write the chapter manifest atomically.&lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
    &lt;span class="n"&gt;tmp&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;manifest_path&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.tmp&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
    &lt;span class="k"&gt;with&lt;/span&gt; &lt;span class="nf"&gt;open&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;tmp&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;w&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;encoding&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;utf-8&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dump&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;organized&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;indent&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;replace&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;tmp&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;manifest_path&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;


&lt;span class="c1"&gt;# Usage
&lt;/span&gt;&lt;span class="n"&gt;result&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;organize_chapters&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="n"&gt;source_dir&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;generated&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;output_base&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;chapters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;languages&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;en&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;es&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="nf"&gt;save_manifest&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;result&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;chapters/manifest.json&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Organized &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nf"&gt;sum&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nf"&gt;len&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;values&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt; files&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;This script is safe to re-run. &lt;code&gt;os.makedirs(..., exist_ok=True)&lt;/code&gt; won't fail if directories already exist. &lt;code&gt;os.replace()&lt;/code&gt; won't fail if the destination already exists from a previous partial run.&lt;/p&gt;




&lt;p&gt;The pipeline uses &lt;code&gt;os&lt;/code&gt; and &lt;code&gt;pathlib&lt;/code&gt; together for every file operation — organizing chapters, managing state files, and cleaning up temp dirs: &lt;a href="https://germy5.gumroad.com/l/xhxkzz" rel="noopener noreferrer"&gt;germy5.gumroad.com/l/xhxkzz&lt;/a&gt; — pay what you want, min $9.99.&lt;/p&gt;




&lt;h2&gt;
  
  
  Further Reading
&lt;/h2&gt;

&lt;ul&gt;
&lt;li&gt;&lt;a href="https://dev.to/german_yamil_e021eef8710d/python-pathlib-replace-ospath-with-cleaner-file-handling-o10"&gt;Python pathlib: Replace os.path with Cleaner File Handling&lt;/a&gt;&lt;/li&gt;
&lt;li&gt;&lt;a href="https://dev.to/german_yamil_e021eef8710d/python-context-managers-the-with-statement-beyond-file-handling-n3f"&gt;Python Context Managers: The with Statement Beyond File Handling&lt;/a&gt;&lt;/li&gt;
&lt;li&gt;&lt;a href="https://dev.to/german_yamil_e021eef8710d/python-subprocessrun-deep-dive-isolation-timeouts-and-captured-output-kh3"&gt;Python subprocess.run() Deep Dive: Isolation, Timeouts, and Captured Output&lt;/a&gt;&lt;/li&gt;
&lt;/ul&gt;

</description>
      <category>python</category>
      <category>beginners</category>
      <category>tutorial</category>
      <category>career</category>
    </item>
    <item>
      <title>How to add automatic LLM fallbacks to your voice pipeline</title>
      <dc:creator>Mart Schweiger</dc:creator>
      <pubDate>Tue, 12 May 2026 18:01:08 +0000</pubDate>
      <link>https://dev.to/martschweiger/how-to-add-automatic-llm-fallbacks-to-your-voice-pipeline-4cn0</link>
      <guid>https://dev.to/martschweiger/how-to-add-automatic-llm-fallbacks-to-your-voice-pipeline-4cn0</guid>
      <description>&lt;p&gt;Your voice agent is mid-conversation when Anthropic's API returns a 529 overloaded error. The user is waiting. Your code throws. The call drops.&lt;/p&gt;

&lt;p&gt;This is the failure mode most voice pipelines aren't built for—and it's getting worse, not better. As more applications move to a single LLM provider, a regional outage at any one of them stalls every downstream voice agent that depends on it. The fix isn't more retries on the same model; it's an automatic switch to a different one.&lt;/p&gt;

&lt;p&gt;This tutorial walks you through adding automatic LLM fallbacks to a voice pipeline using AssemblyAI's LLM Gateway. With one extra parameter in your request, the Gateway will automatically retry failed calls on a backup model—Claude to Gemini to GPT—without you writing a line of retry logic. By the end, you'll have a runnable Python pipeline that transcribes live audio with Universal-3 Pro Streaming, routes the transcript through a primary LLM with a fallback chain, and stays online when any single provider does not.&lt;/p&gt;

&lt;h2&gt;
  
  
  Why fallbacks matter more for voice than for chat
&lt;/h2&gt;

&lt;p&gt;In a chat app, an LLM error means a spinner and a retry button. In a Voice AI pipeline, it means dead air. The user is on the phone, waiting for a response, and a five-second silence while you reconnect to a different provider already feels like a hang-up.&lt;/p&gt;

&lt;p&gt;Three failure modes that fallbacks solve:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Provider rate limits.&lt;/strong&gt; OpenAI, Anthropic, and Google all enforce per-account TPM (tokens per minute) ceilings. A traffic spike on a Monday morning sales line can blow through your default tier before lunch.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Regional outages.&lt;/strong&gt; Provider status pages show a real distribution of multi-hour incidents per quarter. If your only LLM call is to a single model, your uptime is capped at theirs.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Model deprecations.&lt;/strong&gt; A model gets sunset on short notice. Without a fallback configured, every voice session that hits the deprecated model fails until you ship a code change.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;LLM Gateway sits in front of every supported provider. You point your client at one endpoint, specify a primary model, and list one or two fallbacks. When the primary fails—overloaded, rate-limited, or unavailable—the Gateway transparently retries on the next model in line and returns the response as if nothing went wrong.&lt;/p&gt;

&lt;h2&gt;
  
  
  What you'll build
&lt;/h2&gt;

&lt;p&gt;A Python voice pipeline that:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Streams microphone audio to AssemblyAI's Universal-3 Pro streaming speech-to-text model&lt;/li&gt;
&lt;li&gt;On end-of-turn, sends the final transcript to LLM Gateway with kimi-k2.5 as the primary model and claude-sonnet-4-6 as the fallback&lt;/li&gt;
&lt;li&gt;Prints the agent's response—and logs which model actually handled the call&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;You'll also see how to chain multiple fallbacks, override prompts per fallback model, and tune retry behavior.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Stack:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;AssemblyAI Universal-3 Pro Streaming (speech-to-text)&lt;/li&gt;
&lt;li&gt;AssemblyAI LLM Gateway (LLM routing with fallbacks)&lt;/li&gt;
&lt;li&gt;Python 3.9+&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Setup
&lt;/h2&gt;

&lt;p&gt;Install the dependencies:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;pip &lt;span class="nb"&gt;install &lt;/span&gt;assemblyai requests python-dotenv pyaudio
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Create a .env file with your API key:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="nv"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;your_key_here
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;You only need one key. The same key authenticates both the streaming STT WebSocket and the LLM Gateway endpoint—no separate accounts with OpenAI, Anthropic, or Google required.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 1: Connect to Universal-3 Pro Streaming
&lt;/h2&gt;

&lt;p&gt;For a voice agent, you want the lowest-latency path from speech to text, then immediately hand the transcript to the LLM. We'll use AssemblyAI's v3 streaming API, which returns immutable final transcripts in roughly 300ms.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;
&lt;span class="kn"&gt;from&lt;/span&gt; &lt;span class="n"&gt;dotenv&lt;/span&gt; &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;load_dotenv&lt;/span&gt;
&lt;span class="kn"&gt;from&lt;/span&gt; &lt;span class="n"&gt;assemblyai.streaming.v3&lt;/span&gt; &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingClientOptions&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingParameters&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;BeginEvent&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;TurnEvent&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;TerminationEvent&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingError&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="nf"&gt;load_dotenv&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="n"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getenv&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;on_begin&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;BeginEvent&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Session started: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nb"&gt;id&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;on_turn&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;TurnEvent&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;end_of_turn&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="se"&gt;\n&lt;/span&gt;&lt;span class="s"&gt;User: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;transcript&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="nf"&gt;respond_with_fallback&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;transcript&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;else&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="se"&gt;\r&lt;/span&gt;&lt;span class="s"&gt;Partial: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;transcript&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;end&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;""&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;on_error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;error&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingError&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;STT error: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;error&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;on_terminated&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;TerminationEvent&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Session terminated&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The on_turn handler is where the LLM call happens. Every time the user finishes speaking, we hand the final transcript to respond_with_fallback—the function we're about to define.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 2: Add the fallback chain
&lt;/h2&gt;

&lt;p&gt;Here's the part that matters. A standard chat completions request looks like this:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;respond_with_fallback&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="n"&gt;response&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;requests&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;post&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;https://llm-gateway.assemblyai.com/v1/chat/completions&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;headers&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;authorization&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;kimi-k2.5&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;  &lt;span class="c1"&gt;# Primary: fast, low-latency
&lt;/span&gt;            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;messages&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;system&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;You are a helpful voice assistant. Keep responses to one or two short sentences.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;user&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;],&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;max_tokens&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;200&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;fallbacks&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;claude-sonnet-4-6&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;   &lt;span class="c1"&gt;# First fallback
&lt;/span&gt;                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;gemini-2.5-flash&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;    &lt;span class="c1"&gt;# Second fallback
&lt;/span&gt;            &lt;span class="p"&gt;],&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;fallback_config&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;depth&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;      &lt;span class="c1"&gt;# Try up to two fallbacks
&lt;/span&gt;        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="n"&gt;timeout&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;response&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;status_code&lt;/span&gt; &lt;span class="o"&gt;!=&lt;/span&gt; &lt;span class="mi"&gt;200&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;All models failed: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;response&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;text&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt;

    &lt;span class="n"&gt;result&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;response&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
    &lt;span class="n"&gt;actual_model&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;reply&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;result&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;choices&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;message&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;

    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Agent (&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;actual_model&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;): &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;reply&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;reply&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;A few details that matter for production:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;The model field in the response reflects which model actually answered. If your primary failed and the Gateway used Claude instead, you'll see claude-sonnet-4-6 in the response—and you'll only be billed for that model.&lt;/li&gt;
&lt;li&gt;Without a fallbacks array, the Gateway still does one automatic retry on the primary after 500ms (default fallback_config.retry: true). That handles transient blips. The fallback array handles outright failures.&lt;/li&gt;
&lt;li&gt;fallback_config.depth controls how many fallbacks to try. Setting it to 2 means the Gateway will try the primary, then the first fallback, then the second.&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Step 3: Choose the right primary and fallback models
&lt;/h2&gt;

&lt;p&gt;Latency and capability vary widely across providers. For voice, you want a fast primary because the user is waiting in real time, and a more reliable secondary in case the fast one is overloaded.&lt;/p&gt;

&lt;p&gt;Pulled from the LLM Gateway model list, here are sensible voice agent pairings:&lt;/p&gt;

&lt;div class="table-wrapper-paragraph"&gt;&lt;table&gt;
&lt;thead&gt;
&lt;tr&gt;
&lt;th&gt;Use case&lt;/th&gt;
&lt;th&gt;Primary&lt;/th&gt;
&lt;th&gt;Fallback 1&lt;/th&gt;
&lt;th&gt;Fallback 2&lt;/th&gt;
&lt;th&gt;Why&lt;/th&gt;
&lt;/tr&gt;
&lt;/thead&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td&gt;Latency-critical (phone agent)&lt;/td&gt;
&lt;td&gt;kimi-k2.5 (~1.2s)&lt;/td&gt;
&lt;td&gt;gemini-2.5-flash-lite (~1.1s)&lt;/td&gt;
&lt;td&gt;gpt-5-nano (~3.2s)&lt;/td&gt;
&lt;td&gt;All low latency; different providers&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Quality-first (clinical, legal)&lt;/td&gt;
&lt;td&gt;claude-sonnet-4-6&lt;/td&gt;
&lt;td&gt;gemini-2.5-pro&lt;/td&gt;
&lt;td&gt;gpt-5.1&lt;/td&gt;
&lt;td&gt;Highest quality models in each provider&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Balanced (most consumer apps)&lt;/td&gt;
&lt;td&gt;gpt-5.2 (~1.6s)&lt;/td&gt;
&lt;td&gt;claude-haiku-4-5-20251001 (~4.1s)&lt;/td&gt;
&lt;td&gt;kimi-k2.5&lt;/td&gt;
&lt;td&gt;Speed + cross-provider redundancy&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;&lt;/div&gt;

&lt;p&gt;The key constraint: your fallbacks should be on different providers from the primary. A Claude Sonnet to Claude Haiku fallback won't help during an Anthropic outage—both calls hit the same upstream.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 4: Override fields per fallback
&lt;/h2&gt;

&lt;p&gt;Sometimes a fallback model needs a different prompt. Maybe your primary uses a 4,000-token system prompt that your cheaper fallback doesn't have the context window for. Or you want the fallback to be more concise to keep latency in check.&lt;/p&gt;

&lt;p&gt;LLM Gateway lets you override any request field per fallback:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;fallbacks&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;claude-sonnet-4-6&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;messages&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
            &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;system&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Be very concise. One sentence max.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;user&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;max_tokens&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;80&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;],&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Any field you don't override is inherited from the original request. This is especially useful when your primary is tuned with a long, detailed system prompt and you want a stripped-down version on the backup.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 5: Putting it all together
&lt;/h2&gt;

&lt;p&gt;Wire the streaming client to your fallback-enabled response function:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;assemblyai&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="n"&gt;aai&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;main&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="nc"&gt;StreamingClientOptions&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
            &lt;span class="n"&gt;api_key&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="n"&gt;api_host&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;streaming.assemblyai.com&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;on&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;Begin&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;on_begin&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;on&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;Turn&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;on_turn&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;on&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;Termination&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;on_terminated&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;on&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;on_error&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;connect&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="nc"&gt;StreamingParameters&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
            &lt;span class="n"&gt;speech_model&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;u3-rt-pro&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="n"&gt;sample_rate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;16000&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="k"&gt;try&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stream&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;aai&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;extras&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;MicrophoneStream&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;sample_rate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;16000&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
    &lt;span class="k"&gt;finally&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;disconnect&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;terminate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;__name__&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;__main__&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="nf"&gt;main&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Run it, speak into your microphone, and watch the printed model name. Then—if you want to see the fallback fire—set the primary model parameter to a deliberately invalid string like "this-model-does-not-exist". The Gateway will fail the primary, immediately route to your first fallback, and return a normal response with the fallback model name in the output.&lt;/p&gt;

&lt;h2&gt;
  
  
  What this gets you in production
&lt;/h2&gt;

&lt;p&gt;Three changes to your voice pipeline as soon as fallbacks are in place:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;
&lt;strong&gt;Provider outages stop being your incidents.&lt;/strong&gt; When Anthropic, OpenAI, or Google has a regional issue, your voice sessions keep flowing—they just route through whichever provider is healthy. You don't get paged.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Rate-limit spikes self-heal.&lt;/strong&gt; A traffic spike that would have hit your TPM ceiling on the primary now spreads across providers automatically.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Model migrations are zero-downtime.&lt;/strong&gt; When a new model ships, you can flip the primary to the new model and keep the old one as a fallback. If anything goes wrong, traffic falls back automatically while you debug.&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;You can layer more on top of this—separate fallback chains per use case, EU-resident endpoints for GDPR compliance, prompt caching to amortize cost—but the single fallbacks array gets you 90% of the resilience for two extra lines of JSON.&lt;/p&gt;

&lt;h2&gt;
  
  
  What to build next
&lt;/h2&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Pair fallbacks with&lt;/strong&gt; &lt;a href="https://www.assemblyai.com/docs/llm-gateway/chat-completions" rel="noopener noreferrer"&gt;&lt;strong&gt;streaming chat completions&lt;/strong&gt;&lt;/a&gt; so the user hears the first sentence while the LLM is still generating the rest.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Add&lt;/strong&gt; &lt;a href="https://www.assemblyai.com/docs/llm-gateway/tool-calling" rel="noopener noreferrer"&gt;&lt;strong&gt;tool calling&lt;/strong&gt;&lt;/a&gt; to let your voice agent look up orders, schedule callbacks, or transfer to a human—same fallback behavior carries through.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Consolidate to one API.&lt;/strong&gt; If you're managing this on top of a separate STT provider, AssemblyAI's Voice Agent API bundles speech understanding, LLM reasoning, and voice generation into a single WebSocket—same fallback patterns apply at the LLM layer, and there's nothing to wire together.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Voice agents need to be built for the failures that will actually happen, not the happy path. Fallbacks turn LLM availability from a single point of failure into a non-event.&lt;/p&gt;

&lt;h2&gt;
  
  
  Frequently asked questions
&lt;/h2&gt;

&lt;h3&gt;
  
  
  What is an LLM fallback and why does my voice pipeline need one?
&lt;/h3&gt;

&lt;p&gt;An LLM fallback is a backup model that automatically takes over when your primary model fails—whether from a provider outage, rate limit, or transient error. Voice pipelines need fallbacks because a failed LLM call means dead air on a live call, which is much worse than a failed text request that the user can retry. With AssemblyAI's LLM Gateway, you specify a fallbacks array in your request and the Gateway transparently retries on the next model if the primary fails—no custom retry logic required.&lt;/p&gt;

&lt;h3&gt;
  
  
  How does AssemblyAI's LLM Gateway handle automatic LLM failover?
&lt;/h3&gt;

&lt;p&gt;LLM Gateway accepts a fallbacks array of up to two backup models per request. If the primary model fails, the Gateway automatically retries the request with the first fallback, then the second, until one succeeds. The response payload reflects the model that actually answered, and you're billed only for that model. By default, the Gateway also performs one automatic retry on the primary after 500 ms to handle transient errors before falling back to a different provider.&lt;/p&gt;

&lt;h3&gt;
  
  
  Which LLM providers does AssemblyAI's LLM Gateway support for fallback chains?
&lt;/h3&gt;

&lt;p&gt;LLM Gateway supports 25+ models across Anthropic Claude (Opus 4.7, Sonnet 4.6, Haiku 4.5), OpenAI GPT (GPT-5.2, 5.1, 5, 4.1, mini, nano, gpt-oss), Google Gemini (3 Flash Preview, 2.5 Pro/Flash/Flash-Lite), Alibaba Cloud Qwen, and Moonshot AI Kimi. For voice fallback chains, the key constraint is to chain across different providers—a Claude to Claude fallback won't help during an Anthropic outage because both calls hit the same upstream.&lt;/p&gt;

&lt;h3&gt;
  
  
  How do I add automatic LLM fallbacks to my voice pipeline?
&lt;/h3&gt;

&lt;p&gt;Add a fallbacks array to your chat/completions request body—that's it. The Gateway handles retries, model switching, and billing automatically. A typical voice agent pairing is kimi-k2.5 as the primary (~1.2s latency), claude-sonnet-4-6 as the first fallback for higher quality, and gemini-2.5-flash-lite as a second fallback for additional provider redundancy. Set fallback_config.depth: 2 to use both backups.&lt;/p&gt;

&lt;h3&gt;
  
  
  Can I customize the prompt or temperature for each fallback model?
&lt;/h3&gt;

&lt;p&gt;Yes—LLM Gateway lets you override any request field per fallback. This is useful when your primary uses a long, detailed system prompt that a smaller fallback can't accommodate, or when you want the fallback to be more concise to keep latency in check. Any field you don't override on the fallback is inherited from the original request, so you only need to specify what changes.&lt;/p&gt;

&lt;h3&gt;
  
  
  How does billing work when an LLM Gateway request falls back to a different model?
&lt;/h3&gt;

&lt;p&gt;You're charged only for the model that actually returned the response, at that model's per-token rate. If your primary fails and the Gateway retries with a fallback, you pay only for the fallback model's tokens—not for the failed primary attempt. All usage shows up on a single AssemblyAI invoice across providers, with no markup on top of model rates.&lt;/p&gt;

&lt;h3&gt;
  
  
  What's the difference between LLM Gateway fallbacks and writing my own retry logic?
&lt;/h3&gt;

&lt;p&gt;LLM Gateway fallbacks handle the entire retry-and-route flow inside the Gateway, so your application code makes one request and gets one response—no custom timeout handling, no model-switching logic, no per-provider error mapping. Writing it yourself works for chat apps where a few seconds of retry latency is fine, but in a voice pipeline every second of dead air costs you, and built-in fallbacks fire faster than client-side retries because the Gateway is already inside the network path.&lt;/p&gt;

</description>
      <category>ai</category>
      <category>python</category>
      <category>tutorial</category>
      <category>llm</category>
    </item>
    <item>
      <title>Stream LLM responses in a voice pipeline: Tool calling, structured outputs, and real-time actions</title>
      <dc:creator>Mart Schweiger</dc:creator>
      <pubDate>Tue, 12 May 2026 17:59:55 +0000</pubDate>
      <link>https://dev.to/martschweiger/stream-llm-responses-in-a-voice-pipeline-tool-calling-structured-outputs-and-real-time-actions-1h67</link>
      <guid>https://dev.to/martschweiger/stream-llm-responses-in-a-voice-pipeline-tool-calling-structured-outputs-and-real-time-actions-1h67</guid>
      <description>&lt;p&gt;When a user finishes a sentence in a voice conversation, they expect to hear the agent start replying within roughly a second. Anything longer feels broken. The fastest way to hit that target isn't a faster LLM—it's not waiting for the LLM to finish before you start speaking.&lt;/p&gt;

&lt;p&gt;Streaming the LLM response, sentence by sentence, into a TTS engine is the trick that turns a 4-second response time into a sub-second one. And once you're streaming, you can layer on tool calling for real-world actions and structured outputs for predictable downstream code—all without giving up that latency budget.&lt;/p&gt;

&lt;p&gt;This tutorial walks through how to build that pipeline using AssemblyAI's LLM Gateway and Universal-3 Pro Streaming. By the end, you'll have a Python voice pipeline that:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Streams microphone audio into AssemblyAI for live transcription&lt;/li&gt;
&lt;li&gt;Streams the LLM response token-by-token through LLM Gateway&lt;/li&gt;
&lt;li&gt;Calls tools mid-conversation to look up data or trigger actions&lt;/li&gt;
&lt;li&gt;Returns structured JSON when the workflow needs predictable output&lt;/li&gt;
&lt;li&gt;Hands each completed sentence to TTS as it arrives&lt;/li&gt;
&lt;/ol&gt;

&lt;h2&gt;
  
  
  Why streaming matters more in voice than in chat
&lt;/h2&gt;

&lt;p&gt;In a chat UI, streaming is a nice-to-have—you see the response appear word by word instead of all at once. In a voice agent, it's the difference between conversational and broken.&lt;/p&gt;

&lt;p&gt;The math is simple. End-to-end voice latency is roughly:&lt;/p&gt;

&lt;p&gt;STT finalization (200-500 ms)&lt;br&gt;&lt;br&gt;
+ LLM time-to-first-token (150-400 ms)&lt;br&gt;&lt;br&gt;
+ TTS time-to-first-audio (200-400 ms)&lt;br&gt;&lt;br&gt;
+ network overhead (50-150 ms)&lt;br&gt;&lt;br&gt;
= 600-1500 ms before the user hears anything  &lt;/p&gt;

&lt;p&gt;If you wait for the full LLM response before sending text to TTS, add another 1-3 seconds onto that. Users notice. Conversation breaks. They start over.&lt;/p&gt;

&lt;p&gt;If you stream—flushing each completed sentence to TTS as soon as the LLM emits it—the user hears the first sentence while the LLM is still generating the second. End-to-end latency stays inside the 600-900 ms range that feels conversational.&lt;/p&gt;
&lt;h2&gt;
  
  
  What you'll build
&lt;/h2&gt;

&lt;p&gt;A Python pipeline that handles three voice agent patterns:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;
&lt;strong&gt;Streamed conversational replies&lt;/strong&gt;—the user asks a question; the agent's voice starts within ~1 second and flows naturally&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Tool calling&lt;/strong&gt;—the user says "what's my order status?"; the agent calls get_order_status(order_id) and speaks the result&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Structured outputs&lt;/strong&gt;—the agent returns a JSON object matching a schema (e.g., {intent, urgency, escalate}), which your code consumes directly without parsing freeform text&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;&lt;strong&gt;Stack:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;AssemblyAI Universal-3 Pro Streaming (speech-to-text)&lt;/li&gt;
&lt;li&gt;AssemblyAI LLM Gateway (streaming chat completions, tools, structured outputs)&lt;/li&gt;
&lt;li&gt;A TTS engine of your choice (we'll use a placeholder—same pattern works with any streaming TTS)&lt;/li&gt;
&lt;li&gt;Python 3.9+&lt;/li&gt;
&lt;/ul&gt;
&lt;h2&gt;
  
  
  Setup
&lt;/h2&gt;


&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;pip &lt;span class="nb"&gt;install &lt;/span&gt;assemblyai requests python-dotenv pyaudio
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;


&lt;p&gt;Create .env:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight conf"&gt;&lt;code&gt;&lt;span class="n"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;=&lt;span class="n"&gt;your_key_here&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The same AssemblyAI API key authenticates both the streaming STT WebSocket and the LLM Gateway endpoint.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 1: Stream tokens from LLM Gateway
&lt;/h2&gt;

&lt;p&gt;LLM Gateway supports OpenAI-style streaming on OpenAI models. Set stream: True in the request and read the response as a Server-Sent Events (SSE) stream. Each chunk contains a partial token; you stitch them together as they arrive.&lt;/p&gt;

&lt;p&gt;The key trick for voice: don't wait for the full response. Buffer tokens, watch for sentence boundaries (., !, ?), and flush each completed sentence to TTS the instant it's ready.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;requests&lt;/span&gt;
&lt;span class="kn"&gt;from&lt;/span&gt; &lt;span class="n"&gt;dotenv&lt;/span&gt; &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;load_dotenv&lt;/span&gt;

&lt;span class="nf"&gt;load_dotenv&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="n"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getenv&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;stream_llm_response&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;
    Stream the LLM response. Yield each completed sentence as it&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s generated.
    &lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
    &lt;span class="n"&gt;response&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;requests&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;post&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;https://llm-gateway.assemblyai.com/v1/chat/completions&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;headers&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;authorization&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;gpt-5.2&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;messages&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;system&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;You are a friendly voice assistant. Keep replies short.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;user&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;],&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;stream&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;max_tokens&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;300&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="n"&gt;stream&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;timeout&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;15&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="nb"&gt;buffer&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;""&lt;/span&gt;
    &lt;span class="n"&gt;sentence_endings&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;!&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;?&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;response&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;iter_lines&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;continue&lt;/span&gt;
        &lt;span class="n"&gt;line&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;decode&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;utf-8&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;startswith&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;data: &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
            &lt;span class="k"&gt;continue&lt;/span&gt;
        &lt;span class="n"&gt;data&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="mi"&gt;6&lt;/span&gt;&lt;span class="p"&gt;:]&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;data&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;[DONE]&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;strip&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
                &lt;span class="k"&gt;yield&lt;/span&gt; &lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;strip&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
            &lt;span class="k"&gt;return&lt;/span&gt;

        &lt;span class="n"&gt;chunk&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;loads&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;data&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="n"&gt;delta&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;chunk&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;choices&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;delta&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;""&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;delta&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;continue&lt;/span&gt;
        &lt;span class="nb"&gt;buffer&lt;/span&gt; &lt;span class="o"&gt;+=&lt;/span&gt; &lt;span class="n"&gt;delta&lt;/span&gt;

        &lt;span class="k"&gt;while&lt;/span&gt; &lt;span class="nf"&gt;any&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;!=&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;sentence_endings&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
            &lt;span class="n"&gt;split_idx&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;rfind&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;sentence_endings&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
            &lt;span class="n"&gt;sentence&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;[:&lt;/span&gt; &lt;span class="n"&gt;split_idx&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;strip&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
            &lt;span class="nb"&gt;buffer&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="n"&gt;split_idx&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt; &lt;span class="p"&gt;:]&lt;/span&gt;
            &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;sentence&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                &lt;span class="k"&gt;yield&lt;/span&gt; &lt;span class="n"&gt;sentence&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The generator yields each completed sentence as it's ready. Your TTS engine consumes these one at a time:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;speak&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;sentence&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;Send a sentence to your TTS engine. Replace with your provider&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s API.&lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;  [TTS] &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;sentence&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="c1"&gt;# tts_client.stream(sentence)
&lt;/span&gt;
&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;handle_final_transcript&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;User: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;sentence&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="nf"&gt;stream_llm_response&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
        &lt;span class="nf"&gt;speak&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;sentence&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;This single change—yielding sentences as they arrive instead of waiting for the full reply—typically cuts perceived response time by 60-80% for any reply longer than two sentences.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 2: Add tool calling
&lt;/h2&gt;

&lt;p&gt;Voice agents become useful the moment they can do something—look up an order, check inventory, schedule a callback, transfer to a human. LLM Gateway supports OpenAI-compatible tool calling across every supported model (Claude, OpenAI, Gemini), so you write the code once and it works no matter which provider you route to.&lt;/p&gt;

&lt;p&gt;Define your tools:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;tools&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;get_order_status&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Look up the status of a customer order by order ID.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;The order ID, e.g. ORD-12345&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                    &lt;span class="p"&gt;}&lt;/span&gt;
                &lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;schedule_callback&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Schedule a callback with a sales rep.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;phone_number&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;preferred_time&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;phone_number&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;preferred_time&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Implement the actual functions:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;get_order_status&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;order_id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;order_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;status&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;shipped&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;eta&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2026-05-09&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;schedule_callback&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;phone_number&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;preferred_time&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;confirmation&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;CB-9982&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;phone&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;phone_number&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;time&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;preferred_time&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="n"&gt;TOOL_REGISTRY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;get_order_status&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;get_order_status&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;schedule_callback&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;schedule_callback&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Now extend the LLM call to handle tool requests. The Gateway returns a tool_calls field on the assistant message; you execute each tool, append the result to the conversation history, and call again to let the model produce its spoken response:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;stream_llm_response_with_history&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;history&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;list&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;model&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;gpt-5.2&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;Stream a follow-up reply using the existing conversation history.&lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
    &lt;span class="n"&gt;response&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;requests&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;post&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;https://llm-gateway.assemblyai.com/v1/chat/completions&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;headers&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;authorization&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;model&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;messages&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;history&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;stream&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;max_tokens&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;300&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="n"&gt;stream&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;timeout&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;15&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="nb"&gt;buffer&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;""&lt;/span&gt;
    &lt;span class="n"&gt;sentence_endings&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;!&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;?&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;response&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;iter_lines&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;continue&lt;/span&gt;
        &lt;span class="n"&gt;line&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;decode&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;utf-8&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;startswith&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;data: &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
            &lt;span class="k"&gt;continue&lt;/span&gt;
        &lt;span class="n"&gt;data&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="mi"&gt;6&lt;/span&gt;&lt;span class="p"&gt;:]&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;data&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;[DONE]&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;strip&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
                &lt;span class="k"&gt;yield&lt;/span&gt; &lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;strip&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
            &lt;span class="k"&gt;return&lt;/span&gt;
        &lt;span class="n"&gt;chunk&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;loads&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;data&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="n"&gt;delta&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;chunk&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;choices&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;delta&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;""&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;delta&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;continue&lt;/span&gt;
        &lt;span class="nb"&gt;buffer&lt;/span&gt; &lt;span class="o"&gt;+=&lt;/span&gt; &lt;span class="n"&gt;delta&lt;/span&gt;
        &lt;span class="k"&gt;while&lt;/span&gt; &lt;span class="nf"&gt;any&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="nb"&gt;buffer&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;sentence_endings&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
            &lt;span class="n"&gt;split_idx&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;rfind&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;sentence_endings&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
            &lt;span class="n"&gt;sentence&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;[:&lt;/span&gt; &lt;span class="n"&gt;split_idx&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;strip&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
            &lt;span class="nb"&gt;buffer&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nb"&gt;buffer&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="n"&gt;split_idx&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt; &lt;span class="p"&gt;:]&lt;/span&gt;
            &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;sentence&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                &lt;span class="k"&gt;yield&lt;/span&gt; &lt;span class="n"&gt;sentence&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;respond_with_tools&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;history&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;list&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="n"&gt;history&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;append&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;user&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;})&lt;/span&gt;

    &lt;span class="n"&gt;response&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;requests&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;post&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;https://llm-gateway.assemblyai.com/v1/chat/completions&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;headers&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;authorization&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;claude-sonnet-4-6&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;messages&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;history&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tools&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;tools&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;max_tokens&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;500&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

    &lt;span class="n"&gt;message&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;response&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;choices&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;message&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
    &lt;span class="n"&gt;history&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;append&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;message&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;message&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tool_calls&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
        &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;tool_call&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;message&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tool_calls&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]:&lt;/span&gt;
            &lt;span class="n"&gt;fn_name&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;tool_call&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
            &lt;span class="n"&gt;fn_args&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;loads&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;tool_call&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;arguments&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt;
            &lt;span class="n"&gt;result&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;TOOL_REGISTRY&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="n"&gt;fn_name&lt;/span&gt;&lt;span class="p"&gt;](&lt;/span&gt;&lt;span class="o"&gt;**&lt;/span&gt;&lt;span class="n"&gt;fn_args&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

            &lt;span class="n"&gt;history&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;append&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tool&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tool_call_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;tool_call&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dumps&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;result&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
            &lt;span class="p"&gt;})&lt;/span&gt;

        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nf"&gt;stream_llm_response_with_history&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;history&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;model&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;gpt-5.2&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;_yield_once&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
        &lt;span class="k"&gt;yield&lt;/span&gt; &lt;span class="n"&gt;message&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nf"&gt;_yield_once&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;stream_llm_response_with_history is the same streaming function from Step 1, except it sends the full conversation history (which now includes the tool result) so the model can speak the answer naturally.&lt;/p&gt;

&lt;p&gt;The clean part: tool calling and streaming compose. The model thinks for a moment ("let me check that for you"), executes the tool, and then streams the spoken result token by token—exactly the conversational rhythm users expect.&lt;/p&gt;

&lt;p&gt;A note for entity-heavy use cases: if your tool parameters include order IDs, phone numbers, or email addresses, your speech-to-text accuracy on those tokens is what determines whether tool calls succeed. Universal-3 Pro Streaming has roughly 16.7% mixed-entity error rate vs. 23-25% for competing models—that's the difference between ORD-12345 and or 12 three 45 getting passed to your function.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 3: Use structured outputs for predictable JSON
&lt;/h2&gt;

&lt;p&gt;Sometimes you don't want a spoken reply—you want machine-readable output your downstream code can act on. Routing decisions, intent classification, sentiment scoring, escalation flags. LLM Gateway supports structured outputs via JSON schema, which guarantees the model returns exactly the shape you specified.&lt;/p&gt;

&lt;p&gt;Define the schema:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;classification_schema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;intent&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;enum&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;billing&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;support&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;sales&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;cancel&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;other&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;urgency&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;enum&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;low&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;medium&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;high&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;escalate&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;boolean&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;summary&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;intent&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;urgency&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;escalate&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;summary&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Send it with response_format:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;classify_utterance&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="n"&gt;response&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;requests&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;post&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;https://llm-gateway.assemblyai.com/v1/chat/completions&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;headers&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;authorization&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;gpt-5.2&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;messages&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;system&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Classify the user&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s intent for a customer service workflow.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;user&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;],&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;response_format&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;json_schema&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;json_schema&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;intent_classification&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;schema&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;classification_schema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;strict&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;loads&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;response&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;choices&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;message&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt;

&lt;span class="n"&gt;classification&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;classify_utterance&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;I want to cancel my subscription right now.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="c1"&gt;# {"intent": "cancel", "urgency": "high", "escalate": True, "summary": "..."}
&lt;/span&gt;
&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;classification&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;escalate&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]:&lt;/span&gt;
    &lt;span class="nf"&gt;transfer_to_human&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;You get back a parsed dict you can route on directly. Pair this with streaming for the user-facing reply: classify the intent (structured), then stream a conversational acknowledgment based on the classification. The user hears a friendly sentence in under a second while your code routes the call in the background.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 4: Wire it all together with streaming STT
&lt;/h2&gt;

&lt;p&gt;The full pipeline looks like this—STT WebSocket on the inbound side, streamed LLM Gateway responses on the outbound side, with tool calls and structured outputs available when needed:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;from&lt;/span&gt; &lt;span class="n"&gt;assemblyai.streaming.v3&lt;/span&gt; &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingClientOptions&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingParameters&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;BeginEvent&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;TurnEvent&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingError&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="n"&gt;conversation_history&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;system&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;You are a helpful voice assistant.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;]&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;on_turn&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;TurnEvent&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;end_of_turn&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt;

    &lt;span class="n"&gt;user_text&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;transcript&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="se"&gt;\n&lt;/span&gt;&lt;span class="s"&gt;User: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="n"&gt;classification&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;classify_utterance&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;classification&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;escalate&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]:&lt;/span&gt;
        &lt;span class="nf"&gt;speak&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Let me get a human on the line for you.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt;

    &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;sentence&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="nf"&gt;respond_with_tools&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;user_text&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;conversation_history&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
        &lt;span class="nf"&gt;speak&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;sentence&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;assemblyai&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="n"&gt;aai&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;main&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="nc"&gt;StreamingClientOptions&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
            &lt;span class="n"&gt;api_key&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="n"&gt;api_host&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;streaming.assemblyai.com&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;on&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;Turn&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;on_turn&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;connect&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="nc"&gt;StreamingParameters&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;speech_model&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;u3-rt-pro&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;sample_rate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;16000&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="k"&gt;try&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stream&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;aai&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;extras&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;MicrophoneStream&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;sample_rate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;16000&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
    &lt;span class="k"&gt;finally&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;disconnect&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;terminate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;__name__&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;__main__&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="nf"&gt;main&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Speak into your microphone, ask about an order ID, and watch the agent execute the tool call and stream the spoken reply back. The combination of streaming STT, streaming LLM, and tool calling produces the responsive voice experience users now expect.&lt;/p&gt;

&lt;h2&gt;
  
  
  When to use which technique
&lt;/h2&gt;

&lt;div class="table-wrapper-paragraph"&gt;&lt;table&gt;
&lt;thead&gt;
&lt;tr&gt;
&lt;th&gt;Pattern&lt;/th&gt;
&lt;th&gt;Use it when&lt;/th&gt;
&lt;/tr&gt;
&lt;/thead&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td&gt;&lt;strong&gt;Streaming reply only&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;The user asked a question; you want a fast, conversational answer&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;&lt;strong&gt;Tool calling + streamed reply&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;The agent needs to act on real data (order lookup, scheduling, transfers)&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;&lt;strong&gt;Structured outputs&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;You need machine-readable output for routing, classification, or downstream logic&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;&lt;strong&gt;Structured + streamed combo&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Classify the intent in JSON, then stream a conversational acknowledgment to the user&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;&lt;/div&gt;

&lt;h2&gt;
  
  
  Skip the wiring with the Voice Agent API
&lt;/h2&gt;

&lt;p&gt;Streaming, tools, structured outputs, and an STT-LLM-TTS pipeline tied together—if you're building a single voice agent and don't need to swap LLM providers per request, AssemblyAI's Voice Agent API bundles all of this behind one WebSocket. You set a system prompt, register tools, and get back streamed audio with built-in turn detection and barge-in. Same Universal-3 Pro Streaming foundation, same fallback patterns, no glue code.&lt;/p&gt;

&lt;p&gt;The lower-level approach in this tutorial is the right call when you need maximum control—choosing different LLMs per request, applying custom retry logic, or running structured-output classification in parallel with the spoken reply. Both paths are first-class on AssemblyAI; pick the one that matches your constraint.&lt;/p&gt;

&lt;p&gt;Streaming everything is the new baseline for voice. Tool calling and structured outputs are what turn a streaming chatbot into something that can actually do work. Build for both and your voice agent stops feeling like a demo.&lt;/p&gt;

&lt;h2&gt;
  
  
  Frequently asked questions
&lt;/h2&gt;

&lt;h3&gt;
  
  
  What does it mean to stream LLM responses in a voice pipeline?
&lt;/h3&gt;

&lt;p&gt;Streaming LLM responses means receiving and processing the model's output token by token as it's generated, instead of waiting for the full response to complete. In a voice pipeline, streaming lets you forward each completed sentence to a text-to-speech engine the moment the LLM emits it—so the user hears the first sentence of the agent's reply while the LLM is still generating the second. This typically cuts perceived response time by 60–80% for any reply longer than two sentences.&lt;/p&gt;

&lt;h3&gt;
  
  
  How do I stream LLM responses through AssemblyAI's LLM Gateway?
&lt;/h3&gt;

&lt;p&gt;Set stream: True in your chat/completions request and read the response as a Server-Sent Events (SSE) stream. Each chunk contains a partial token in the choices[0].delta.content field. Buffer tokens, watch for sentence-ending punctuation, and flush each completed sentence to your TTS engine as soon as it's ready. Streaming is supported on OpenAI models in LLM Gateway today.&lt;/p&gt;

&lt;h3&gt;
  
  
  How does tool calling work with the LLM Gateway?
&lt;/h3&gt;

&lt;p&gt;Tool calling lets your voice agent invoke functions to access data or trigger actions—looking up an order, scheduling a callback, transferring to a human. Define your tools as JSON Schema in the tools array, and when the model decides to call one it returns a tool_calls field on the assistant message. You execute the tool, append the result to the conversation history, and call the Gateway again to let the model produce a spoken response that incorporates the tool output. The schema is OpenAI-compatible, so the same code works across Claude, GPT, and Gemini.&lt;/p&gt;

&lt;h3&gt;
  
  
  Can I get structured JSON outputs from the LLM Gateway for voice agents?
&lt;/h3&gt;

&lt;p&gt;Yes—LLM Gateway supports structured outputs via JSON schema using the response_format parameter. This guarantees the model returns exactly the shape you specified, which is useful for intent classification, routing decisions, sentiment scoring, and any voice agent workflow that needs machine-readable output your downstream code can consume directly. A common voice pattern is to classify intent in JSON first, then stream a conversational acknowledgment back to the user while your code routes the call in the background.&lt;/p&gt;

&lt;h3&gt;
  
  
  What's the latency budget for a real-time voice agent using streamed LLM responses?
&lt;/h3&gt;

&lt;p&gt;A well-tuned voice pipeline targets 600–900 ms from the moment the user stops speaking to the moment they hear the agent's first audio. That budget breaks down roughly as: 200–500 ms for STT finalization, 150–400 ms for LLM time-to-first-token, 200–400 ms for TTS time-to-first-audio, and 50–150 ms of network overhead. Streaming everything—STT transcripts, LLM tokens, TTS audio—is what makes hitting that budget achievable.&lt;/p&gt;

&lt;h3&gt;
  
  
  When should I use the Voice Agent API instead of wiring streaming STT and LLM Gateway separately?
&lt;/h3&gt;

&lt;p&gt;Use the Voice Agent API when you're building a single voice agent and want one WebSocket that handles STT, LLM, TTS, turn detection, and tool calling out of the box. Use the lower-level streaming STT plus LLM Gateway approach when you need more control—choosing different LLMs per request, applying custom retry logic, or running structured-output classification in parallel with the spoken reply. Both options use the same Universal-3 Pro Streaming foundation, so accuracy is identical.&lt;/p&gt;

&lt;h3&gt;
  
  
  Does streaming work with tool calling and structured outputs?
&lt;/h3&gt;

&lt;p&gt;Yes—streaming composes with both. With tool calling, the agent thinks for a moment, executes the tool, then streams the spoken result token by token. With structured outputs, you typically don't stream the JSON itself (you want the complete object before parsing) but you can stream a separate conversational acknowledgment to the user while the structured classification finalizes in parallel.&lt;/p&gt;

</description>
      <category>ai</category>
      <category>python</category>
      <category>tutorial</category>
      <category>llm</category>
    </item>
    <item>
      <title>Build an AI voice agent for customer support that can look up orders</title>
      <dc:creator>Mart Schweiger</dc:creator>
      <pubDate>Tue, 12 May 2026 17:59:18 +0000</pubDate>
      <link>https://dev.to/martschweiger/build-an-ai-voice-agent-for-customer-support-that-can-look-up-orders-1lil</link>
      <guid>https://dev.to/martschweiger/build-an-ai-voice-agent-for-customer-support-that-can-look-up-orders-1lil</guid>
      <description>&lt;p&gt;Tier-1 customer support is mostly the same five conversations on repeat: where's my order, can I change my address, can I get a refund, when does this ship, can I talk to a human. They're predictable, they're high-volume, and they don't need a person—they need a voice agent that can actually look things up.&lt;/p&gt;

&lt;p&gt;This tutorial walks you through building one. By the end, you'll have a Python voice agent that answers calls, listens for an order ID or email, calls into your backend to check the status, and reads the result back to the customer in real time. When something goes off-script, it transfers to a human with the full conversation context attached.&lt;/p&gt;

&lt;p&gt;We're using AssemblyAI's Voice Agent API—one WebSocket that handles the speech understanding, LLM reasoning, voice generation, turn detection, and tool calling in a single connection. Total time to a working prototype: about an afternoon.&lt;/p&gt;

&lt;h2&gt;
  
  
  Why most support voice agents fail
&lt;/h2&gt;

&lt;p&gt;Before we build, it's worth knowing where these things break. The pattern is almost always the same:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Customer says "my order ID is A-B-3-7-9-2"&lt;/li&gt;
&lt;li&gt;STT mishears it as "a b 37 92" or "ABE 379 to"&lt;/li&gt;
&lt;li&gt;The LLM calls get_order_status("ab3792") or worse, asks the customer to repeat&lt;/li&gt;
&lt;li&gt;Customer hangs up&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;The agent didn't fail because the LLM was wrong. It failed because the speech-to-text layer couldn't capture the entity correctly. This is why entity accuracy on alphanumerics, emails, and phone numbers matters more than overall WER for support agents—and why we're building on Universal-3 Pro Streaming, which has a "16.7% mixed-entity error rate vs. 23-25% for competing models."&lt;/p&gt;

&lt;p&gt;The second-most-common failure: dead air during tool calls. The customer asks a question, the agent calls a backend, and there's a 2-3 second silence while the lookup runs. The Voice Agent API solves this by speaking a natural transition phrase ("let me check that for you") while the tool runs—no dead air, no awkward pauses.&lt;/p&gt;

&lt;h2&gt;
  
  
  What you'll build
&lt;/h2&gt;

&lt;p&gt;A Python voice support agent that handles three real workflows:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;
&lt;strong&gt;Order status lookup&lt;/strong&gt;—customer says "where's my order?" then the agent asks for the ID, looks it up, and reads back status, ETA, and tracking number&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Customer info verification&lt;/strong&gt;—customer provides email or phone number, the agent looks up the account, and confirms identity before proceeding&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Human escalation&lt;/strong&gt;—customer asks for a person, or the agent gets stuck, and a graceful transfer happens with conversation context preserved&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;&lt;strong&gt;Stack:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;AssemblyAI Voice Agent API (one WebSocket: STT + LLM + TTS)&lt;/li&gt;
&lt;li&gt;Python 3.9+&lt;/li&gt;
&lt;li&gt;A backend with order data—we'll mock it; replace with your real CRM or order management system&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Setup
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;pip &lt;span class="nb"&gt;install &lt;/span&gt;websockets pyaudio python-dotenv
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Create .env:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight properties"&gt;&lt;code&gt;&lt;span class="py"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;your_key_here&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The Voice Agent API uses a single endpoint: wss://agents.assemblyai.com/v1/ws. One key, one connection, no separate STT or TTS providers to wire in.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 1: Define the support tools
&lt;/h2&gt;

&lt;p&gt;Tools are the agent's interface to your backend. The Voice Agent API uses standard JSON Schema, so anything you can describe with a schema, the agent can call.&lt;/p&gt;

&lt;p&gt;For a support agent, you typically want four tools:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;

&lt;span class="n"&gt;TOOLS&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;get_order_status&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Look up an order&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s current status, shipping ETA, and tracking number by order ID.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;The customer&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s order ID, e.g. ORD-12345 or 78231-ABC.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;lookup_account_by_email&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Find a customer account using their email address.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;email&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;The customer&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s email address.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;email&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;list_recent_orders&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;List the customer&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s most recent orders. Use after the account is verified.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;account_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;limit&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;integer&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Max number of orders to return.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;default&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;5&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;account_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;transfer_to_human&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Transfer the call to a human agent. Use when the customer asks, when you can&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;t help, or when the issue is sensitive.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;reason&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Short reason for the transfer.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;summary&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Brief summary of the conversation so far.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;reason&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;summary&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Now implement the actual functions. Replace these stubs with calls to your real backend:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;ORDERS_DB&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ORD-12345&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;status&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;shipped&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;eta&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2026-05-09&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tracking&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;1Z999AA10123456784&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ORD-67890&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;status&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;processing&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;eta&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2026-05-12&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tracking&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;None&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="n"&gt;ACCOUNTS_DB&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;jane@example.com&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;account_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ACC-001&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Jane Doe&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="n"&gt;ACCOUNT_ORDERS&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ACC-001&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
        &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ORD-12345&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;date&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2026-05-01&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;total&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;$84.99&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ORD-12100&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;date&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2026-04-22&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;total&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;$42.00&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;],&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;run_tool&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;get_order_status&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;order&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;ORDERS_DB&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;upper&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;order&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;error&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_not_found&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]}&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;order&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;lookup_account_by_email&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;account&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;ACCOUNTS_DB&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;email&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;lower&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;account&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;error&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;account_not_found&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;account&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;list_recent_orders&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;ACCOUNT_ORDERS&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;account_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt; &lt;span class="p"&gt;[])&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;orders&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt;&lt;span class="p"&gt;[:&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;limit&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;5&lt;/span&gt;&lt;span class="p"&gt;)]}&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;transfer_to_human&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;transferred&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;queue&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;support-tier-2&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;error&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;unknown_tool: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The error-shape pattern matters. When get_order_status can't find an order, it returns a structured error rather than throwing—that gives the LLM the context it needs to apologize and ask the customer to verify the ID, instead of crashing the conversation.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 2: Write the system prompt
&lt;/h2&gt;

&lt;p&gt;The system prompt is where you encode the agent's behavior. For support, you want a few things every time:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Identity and tone&lt;/li&gt;
&lt;li&gt;When to ask for verification before sharing details&lt;/li&gt;
&lt;li&gt;When to use which tool&lt;/li&gt;
&lt;li&gt;When to transfer to a human&lt;/li&gt;
&lt;li&gt;Specific phrasing for transition moments (the "let me check that" line)
&lt;/li&gt;
&lt;/ul&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;SYSTEM_PROMPT&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;
You are Avery, a customer support agent for Acme Corp. Your goal is to help customers
quickly and accurately. You have access to tools that let you look up orders and accounts.

Behavior rules:
- Greet warmly and ask how you can help.
- For order questions, ask for the order ID first if the customer hasn&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;t given it.
- If a customer gives an email or phone number, use lookup_account_by_email to verify.
- Read order status, ETA, and tracking number clearly. Don&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;t read raw timestamps —
  say dates naturally (e.g., &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Friday, May 9th&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;).
- When you need to call a tool, say a brief transition like &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Let me check on that&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;
  or &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;One moment while I pull that up.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;
- If the customer asks for a human, sounds frustrated, or has a complex issue
  (refund disputes, damaged product, billing errors), use transfer_to_human and
  include a short summary.
- Never make up an order ID, status, or tracking number. If a tool returns an error,
  apologize, ask the customer to verify the ID, and try again.
- Keep replies short and conversational. This is a phone call, not an email.
&lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The "never make up" line is the most important sentence in the prompt. Without it, LLMs sometimes invent plausible-sounding tracking numbers when the lookup fails. With it, they ask for clarification instead.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 3: Connect to the Voice Agent API
&lt;/h2&gt;

&lt;p&gt;Now the WebSocket connection. The pattern is:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Open wss://agents.assemblyai.com/v1/ws with your API key&lt;/li&gt;
&lt;li&gt;Send session.update with the system prompt, tools, voice, and greeting&lt;/li&gt;
&lt;li&gt;Wait for session.ready, then start streaming microphone audio&lt;/li&gt;
&lt;li&gt;Handle incoming events—tool.call, reply.audio, transcript.user, reply.done
&lt;/li&gt;
&lt;/ol&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;asyncio&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;websockets&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;pyaudio&lt;/span&gt;

&lt;span class="n"&gt;API_KEY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getenv&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="n"&gt;WS_URL&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;wss://agents.assemblyai.com/v1/ws&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
&lt;span class="n"&gt;SAMPLE_RATE&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;24000&lt;/span&gt;

&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;run_agent&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
    &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;with&lt;/span&gt; &lt;span class="n"&gt;websockets&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;connect&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="n"&gt;WS_URL&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;additional_headers&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Authorization&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Bearer &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;API_KEY&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="n"&gt;ws&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;ws&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;send&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dumps&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;session.update&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;session&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;system_prompt&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;SYSTEM_PROMPT&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;greeting&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Hi, this is Avery from Acme support. How can I help?&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;output&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;voice&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ivy&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tools&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;TOOLS&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;}))&lt;/span&gt;

        &lt;span class="n"&gt;pa&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;pyaudio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;PyAudio&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
        &lt;span class="n"&gt;mic&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;pa&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;open&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nb"&gt;format&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;pyaudio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;paInt16&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;channels&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;rate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;SAMPLE_RATE&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                      &lt;span class="nb"&gt;input&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;frames_per_buffer&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;1024&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="n"&gt;speaker&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;pa&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;open&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nb"&gt;format&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;pyaudio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;paInt16&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;channels&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;rate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;SAMPLE_RATE&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                          &lt;span class="n"&gt;output&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

        &lt;span class="n"&gt;ready&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;asyncio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;Event&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
        &lt;span class="n"&gt;pending_tools&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[]&lt;/span&gt;

        &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;send_audio&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
            &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;ready&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;wait&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
            &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;base64&lt;/span&gt;
            &lt;span class="k"&gt;while&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                &lt;span class="n"&gt;audio&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;mic&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;read&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1024&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;exception_on_overflow&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;False&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;ws&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;send&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dumps&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;input.audio&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;audio&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;base64&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;b64encode&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;audio&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;decode&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
                &lt;span class="p"&gt;}))&lt;/span&gt;
                &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;asyncio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;sleep&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

        &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;handle_messages&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
            &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;raw&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;ws&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                &lt;span class="n"&gt;event&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;loads&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;raw&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

                &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;session.ready&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="n"&gt;ready&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;set&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
                    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Agent ready. Start speaking.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

                &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;transcript.user&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="se"&gt;\n&lt;/span&gt;&lt;span class="s"&gt;User: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;text&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

                &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;transcript.agent&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Agent: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;text&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

                &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;reply.audio&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;base64&lt;/span&gt;
                    &lt;span class="n"&gt;speaker&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;write&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;base64&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;b64decode&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;data&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]))&lt;/span&gt;

                &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tool.call&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
                    &lt;span class="n"&gt;args&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;arguments&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{})&lt;/span&gt;
                    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;  [tool] &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;(&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;)&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                    &lt;span class="n"&gt;result&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;run_tool&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                    &lt;span class="n"&gt;pending_tools&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;append&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;call_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;call_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;result&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;result&lt;/span&gt;&lt;span class="p"&gt;})&lt;/span&gt;

                &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;reply.done&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;status&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;interrupted&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                        &lt;span class="n"&gt;pending_tools&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;clear&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
                    &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;pending_tools&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                        &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;tool&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;pending_tools&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                            &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;ws&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;send&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dumps&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
                                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tool.result&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;call_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;tool&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;call_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
                                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;result&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dumps&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;tool&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;result&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]),&lt;/span&gt;
                            &lt;span class="p"&gt;}))&lt;/span&gt;
                        &lt;span class="n"&gt;pending_tools&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;clear&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

        &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;asyncio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;gather&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nf"&gt;send_audio&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt; &lt;span class="nf"&gt;handle_messages&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;

&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;__name__&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;__main__&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="n"&gt;asyncio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;run&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nf"&gt;run_agent&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;A few details that the docs flag and you'd otherwise debug for an hour:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Don't send tool.result immediately&lt;/strong&gt; when you receive tool.call. Accumulate results and send them inside the reply.done handler. Sending too early causes timing issues.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Discard pending tool results on interruption.&lt;/strong&gt; If the user speaks while the agent is generating a transition phrase, you'll get reply.done with status: "interrupted"—clear the buffer and wait for the next turn.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Voice names are case-sensitive.&lt;/strong&gt; Use lowercase: ivy, james, mia, winter, bella. An invalid voice returns session.error.&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Step 4: Test the three workflows
&lt;/h2&gt;

&lt;p&gt;Run the script and walk through each support scenario. You should hear:&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Workflow 1—Order lookup:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;You: "Hi, I'm trying to check on order O-R-D 1-2-3-4-5"
Agent: "Sure, let me check on that... I see order ORD-12345. It shipped and is
        on its way — you should have it by Friday, May 9th. The tracking number
        is 1Z999AA10123456784."
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Workflow 2—Email-based account lookup:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;You: "I forgot my order ID. Can you look me up by email?"
Agent: "Of course. What's the email on the account?"
You: "It's jane at example dot com."
Agent: "One moment... Got it, you're Jane Doe. I see two recent orders:
        ORD-12345 from May 1st for $84.99, and ORD-12100 from April 22nd
        for $42.00. Which one are you asking about?"
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Workflow 3—Human transfer:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight json"&gt;&lt;code&gt;&lt;span class="err"&gt;You:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"I just want to talk to a person."&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="err"&gt;Agent:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"I understand. Let me get you over to a teammate now."&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="err"&gt;tool.call:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="err"&gt;transfer_to_human(&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="nl"&gt;"reason"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"user requested human"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="nl"&gt;"summary"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"..."&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="err"&gt;)&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Speak the order ID with hesitation, mumbles, accents, and natural disfluencies—that's where Universal-3 Pro Streaming earns its keep. The agent should still extract the ID correctly because it's tuned for the alphanumeric tokens that voice agents act on.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 5: Take it to the phone
&lt;/h2&gt;

&lt;p&gt;This works in your browser through your microphone, but real customer support runs on phones. Twilio Media Streams is the standard bridge—your server accepts the inbound call from Twilio and opens a parallel connection to the Voice Agent API, forwarding audio in both directions.&lt;/p&gt;

&lt;p&gt;The Voice Agent API supports audio/pcmu (G.711 u-law at 8 kHz) natively, which matches Twilio's codec exactly. No transcoding, no resampling. The Twilio integration guide walks through the full bridge in about 100 lines of TypeScript.&lt;/p&gt;

&lt;h2&gt;
  
  
  What to harden before production
&lt;/h2&gt;

&lt;p&gt;Three things you'll want to nail down before pointing this at real customers:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Replace the in-memory mocks&lt;/strong&gt; with calls to your actual CRM or order management system. Add timeouts and error handling so a slow backend doesn't kill the conversation.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Log everything.&lt;/strong&gt; Save user transcripts, tool calls, results, and the agent's responses tied to a session ID. Conversation logs are your debugging tool when something goes wrong on call #4,712. Conversation intelligence features like speaker diarization can help you analyze these logs at scale.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Tune turn detection for your acoustic environment.&lt;/strong&gt; The defaults work for most use cases. For phone audio with background noise, you may want to raise min_end_of_turn_silence_ms slightly so the agent doesn't cut off thoughtful pauses.&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Where to go from there
&lt;/h2&gt;

&lt;p&gt;Once the basic order-lookup loop works, the same tool-calling pattern extends to every other support workflow you have: cancel an order, update a shipping address, request a refund, schedule a callback, fetch FAQ answers from a knowledge base. Add the function, describe it in the system prompt, and the agent picks it up—no new infrastructure.&lt;/p&gt;

&lt;p&gt;The compounding win: every conversation goes through the same Voice Agent API connection, the same transcription model, the same billing relationship. You're not assembling a new vendor stack; you're adding tools to an agent that already works.&lt;/p&gt;

&lt;h2&gt;
  
  
  Frequently asked questions
&lt;/h2&gt;

&lt;h3&gt;
  
  
  How do I build an AI voice agent for customer support that can look up orders?
&lt;/h3&gt;

&lt;p&gt;Build it on AssemblyAI's Voice Agent API, register a get_order_status function as a tool with JSON Schema, and connect to the WebSocket at wss://agents.assemblyai.com/v1/ws. The agent transcribes the customer's speech, decides when to call your function, executes it through your backend, and speaks the result back—all on a single connection. Most developers ship a working agent in an afternoon because there's no SDK to learn and no separate STT, LLM, or TTS providers to wire together.&lt;/p&gt;

&lt;h3&gt;
  
  
  Why does speech-to-text accuracy matter so much for support voice agents?
&lt;/h3&gt;

&lt;p&gt;Support agents constantly need to capture alphanumeric tokens—order IDs, account numbers, email addresses, phone numbers—and a single transcription error breaks the workflow. If the STT layer mishears "ORD-12345" as "or 12 three 45," your get_order_status function gets a garbled ID and returns nothing. AssemblyAI's Voice Agent API is built on Universal-3 Pro Streaming, which has a "16.7% mixed-entity error rate vs. 23–25% for competing models"—that's the difference between tool calls that succeed and tool calls that silently fail.&lt;/p&gt;

&lt;h3&gt;
  
  
  How does tool calling work with the AssemblyAI Voice Agent API?
&lt;/h3&gt;

&lt;p&gt;You register tools by passing an array of function definitions in session.tools on a session.update event. When the agent decides to call a tool, it emits a tool.call event with the function name and arguments. You execute the function and accumulate results, then send tool.result events inside your reply.done handler—not immediately on tool.call. While the tool runs, the agent speaks a brief transition phrase like "let me check that for you" so the conversation never goes silent.&lt;/p&gt;

&lt;h3&gt;
  
  
  Can I connect AssemblyAI's Voice Agent API to phone calls with Twilio?
&lt;/h3&gt;

&lt;p&gt;Yes—the Voice Agent API supports audio/pcmu (G.711 u-law at 8 kHz) natively, which matches Twilio's codec exactly with no transcoding needed. You set up a server that accepts the inbound Twilio Media Streams call, opens a parallel WebSocket to the Voice Agent API, and forwards audio in both directions. The official Twilio integration guide walks through inbound and outbound calling in about 100 lines of TypeScript.&lt;/p&gt;

&lt;h3&gt;
  
  
  What's the best way to handle escalation to a human in a customer support voice agent?
&lt;/h3&gt;

&lt;p&gt;Register a transfer_to_human tool with parameters for reason and summary, and instruct the agent in the system prompt to call it when the customer asks for a person, sounds frustrated, or has a complex issue (refund disputes, billing errors, damaged products). The agent generates a short summary of the conversation that you forward to your human queue, so the receiving agent doesn't have to ask the customer to repeat themselves. This is one of the most important workflows to design well—a poor handoff feels worse than no AI at all.&lt;/p&gt;

&lt;h3&gt;
  
  
  How much does it cost to run a customer support voice agent on AssemblyAI?
&lt;/h3&gt;

&lt;p&gt;The Voice Agent API is $4.50/hr flat—covering speech understanding, LLM reasoning, voice generation, turn detection, and tool calling all in one bill. There are no per-token surcharges, no concurrency caps, and no separate invoices for STT, LLM, and TTS providers. Pricing is billed by the minute on actual conversation duration, and a free tier is available for testing.&lt;/p&gt;

&lt;h3&gt;
  
  
  Do voice agents built with AssemblyAI work with healthcare workflows?
&lt;/h3&gt;

&lt;p&gt;AssemblyAI offers a BAA for HIPAA workloads and is SOC 2 Type 2, ISO 27001:2022, and PCI DSS v4.0 certified. For clinical use cases (medical front-office voice agents, healthcare contact centers), enable Medical Mode with domain="medical-v1" to improve transcription accuracy on medication names, procedures, conditions, and dosages. Do not point the agent at real PHI without a signed BAA in place.&lt;/p&gt;

</description>
      <category>ai</category>
      <category>python</category>
      <category>tutorial</category>
      <category>webdev</category>
    </item>
    <item>
      <title>Building a voice-powered e-commerce shopping assistant</title>
      <dc:creator>Mart Schweiger</dc:creator>
      <pubDate>Tue, 12 May 2026 17:57:59 +0000</pubDate>
      <link>https://dev.to/martschweiger/building-a-voice-powered-e-commerce-shopping-assistant-30ok</link>
      <guid>https://dev.to/martschweiger/building-a-voice-powered-e-commerce-shopping-assistant-30ok</guid>
      <description>&lt;p&gt;Voice shopping has crossed an inflection point. Search by typing is being replaced by search by saying—"show me waterproof hiking boots under $150 in size 10," "add the second one to my cart," "what's the return policy on these." For e-commerce teams, that's both an opportunity and a problem: the existing product search and checkout flow was designed for clicks and keystrokes, not natural language.&lt;/p&gt;

&lt;p&gt;This tutorial walks through building a voice-powered shopping assistant that customers can actually talk to. By the end, you'll have a Python voice agent that handles four real shopping workflows—product search, add-to-cart, order tracking, and checkout assistance—all on top of a single WebSocket connection using AssemblyAI's Voice Agent API.&lt;/p&gt;

&lt;p&gt;The same pattern works whether you're embedding voice into a mobile shopping app, an in-store kiosk, a smart speaker integration, or a phone-based ordering line.&lt;/p&gt;

&lt;h2&gt;
  
  
  Why voice e-commerce is different from voice support
&lt;/h2&gt;

&lt;p&gt;If you've built a customer support Voice AI agent, the shopping use case looks similar—but the constraints are sharper:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Entity accuracy is everything.&lt;/strong&gt; Sizes ("size ten and a half"), SKUs ("SKU 9-9-2-1-A"), prices ("under one fifty"), quantities ("get me three of those"). Mishear any of those and you've added the wrong item, the wrong size, or the wrong quantity to a cart someone is about to check out with.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Conversations are exploratory.&lt;/strong&gt; Support calls have a clear job-to-be-done; shopping conversations meander. The customer browses, narrows, compares, asks about returns, gets distracted, comes back. The agent has to track all of that without losing context.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Stakes shift mid-conversation.&lt;/strong&gt; "Tell me about this jacket" is low-stakes. "Charge my saved card for $284.50" is not. The agent needs to know when to ask for confirmation and when to just answer.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Accent and code-switching show up.&lt;/strong&gt; Shoppers globally pronounce brand names, colors, and product categories differently. The agent needs to handle that gracefully.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;The Voice Agent API addresses these directly: built on Universal-3 Pro Streaming for high entity accuracy (16.7% mixed-entity error rate vs. 23–25% for competitors), with mid-conversation system prompt updates so you can tighten or loosen the agent's behavior as the customer moves from browsing to buying.&lt;/p&gt;

&lt;h2&gt;
  
  
  What you'll build
&lt;/h2&gt;

&lt;p&gt;A Python voice shopping assistant that handles four workflows:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;
&lt;strong&gt;Product search&lt;/strong&gt;—"show me wireless headphones under $200" → searches your catalog → reads back top results&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Cart management&lt;/strong&gt;—"add the second one in black" → adds to cart → confirms&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Order tracking&lt;/strong&gt;—"where's my order from last week?" → looks up customer orders → reads back status&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Checkout assistance&lt;/strong&gt;—guides the user through review and confirmation, never executing payment without explicit verbal "yes"&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;&lt;strong&gt;Stack:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;AssemblyAI Voice Agent API (one WebSocket: STT + LLM + TTS)&lt;/li&gt;
&lt;li&gt;Python 3.9+&lt;/li&gt;
&lt;li&gt;A product catalog and order DB—we'll mock both; replace with your real Shopify, Commerce Cloud, or BigCommerce backend&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Setup
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;pip &lt;span class="nb"&gt;install &lt;/span&gt;websockets pyaudio python-dotenv

&lt;span class="c"&gt;# .env&lt;/span&gt;
&lt;span class="nv"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;your_key_here
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Endpoint: wss://agents.assemblyai.com/v1/ws. One key, one connection—the same key works for all AssemblyAI products.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 1: Define the shopping tools
&lt;/h2&gt;

&lt;p&gt;The toolset shapes what your agent can do. Start with the four core shopping verbs and grow from there. The Voice Agent API supports tool calling natively, so each tool is defined as a JSON function schema.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;

&lt;span class="n"&gt;TOOLS&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;search_products&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Search the product catalog. Use whenever the customer is browsing or asking what&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s available.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;query&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Free-text query, e.g. &lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;waterproof hiking boots&lt;/span&gt;&lt;span class="sh"&gt;'"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;max_price&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;number&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;size&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;color&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;limit&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;integer&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;default&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;5&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;query&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;get_product_details&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Get full details on a specific product, including return policy and stock.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;add_to_cart&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Add a product to the customer&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s cart. Confirm size, color, and quantity before calling.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Specific size/color variant&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;quantity&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;integer&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;default&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;view_cart&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Read back the customer&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s current cart with subtotal.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{},&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[]},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;remove_from_cart&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Remove an item from the cart by line item ID.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;line_item_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;line_item_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;checkout&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Submit the order using the customer&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s saved payment and shipping. ONLY call after explicit verbal &lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;yes&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt; to a clear confirmation prompt.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;confirmation_phrase&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;The exact phrase the customer said to confirm, e.g. &lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;yes, place the order&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="p"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;confirmation_phrase&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;track_order&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Look up the status of a customer order.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The confirmation_phrase parameter on checkout is the trick that prevents accidental orders. The system prompt tells the agent it can only call checkout if the customer literally says yes—and the parameter forces the agent to record what was said. Your backend can additionally enforce that only a list of accepted phrases ("yes", "place the order", "go ahead") triggers the actual payment.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 2: Implement the backend (mocked)
&lt;/h2&gt;

&lt;p&gt;Replace these stubs with calls to your real catalog and order systems.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;CATALOG&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;SKU-2201&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Trail Runner 3 hiking boots&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;price&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mf"&gt;139.00&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;category&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;footwear&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tags&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;waterproof&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;hiking&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variants&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
            &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;SKU-2201-BK-10&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;size&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;10&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;color&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;black&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;stock&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;4&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;SKU-2201-BK-11&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;size&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;11&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;color&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;black&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;stock&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;SKU-2201-BR-10&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;size&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;10&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;color&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;brown&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;stock&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;7&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;return_policy&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;30-day free returns&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;SKU-3104&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Summit Pro waterproof boots&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;price&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mf"&gt;199.00&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;category&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;footwear&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tags&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;waterproof&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;hiking&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;premium&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variants&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
            &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;SKU-3104-BK-10&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;size&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;10&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;color&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;black&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;stock&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;return_policy&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;30-day free returns&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;]&lt;/span&gt;

&lt;span class="n"&gt;CART&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[]&lt;/span&gt;  &lt;span class="c1"&gt;# In production, scope this per session
&lt;/span&gt;&lt;span class="n"&gt;ORDERS&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ORD-9981&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;status&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;shipped&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;eta&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2026-05-09&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tracking&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;1Z999AA10123456784&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;run_tool&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;search_products&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;results&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
            &lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;CATALOG&lt;/span&gt;
            &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;query&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;lower&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt; &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt; &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tags&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;])).&lt;/span&gt;&lt;span class="nf"&gt;lower&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
            &lt;span class="ow"&gt;and&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;max_price&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="ow"&gt;or&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;price&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;max_price&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt;
        &lt;span class="p"&gt;]&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;results&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;results&lt;/span&gt;&lt;span class="p"&gt;[:&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;limit&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;5&lt;/span&gt;&lt;span class="p"&gt;)]}&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;get_product_details&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;CATALOG&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]:&lt;/span&gt;
                &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;error&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_not_found&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;add_to_cart&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;CATALOG&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variants&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]:&lt;/span&gt;
                &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]:&lt;/span&gt;
                    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;stock&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;quantity&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
                        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;error&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;out_of_stock&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;available&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;stock&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]}&lt;/span&gt;
                    &lt;span class="n"&gt;line&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;line_item_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;LI-&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nf"&gt;len&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;CART&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;product_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;size&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;size&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;color&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;color&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;quantity&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;quantity&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;price&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;price&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
                    &lt;span class="p"&gt;}&lt;/span&gt;
                    &lt;span class="n"&gt;CART&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;append&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;added&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;cart_size&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;len&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;CART&lt;/span&gt;&lt;span class="p"&gt;)}&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;error&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;variant_not_found&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;view_cart&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;subtotal&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;sum&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;item&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;price&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="n"&gt;item&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;quantity&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;item&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;CART&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;items&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;CART&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;subtotal&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;round&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;subtotal&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;)}&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;remove_from_cart&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;global&lt;/span&gt; &lt;span class="n"&gt;CART&lt;/span&gt;
        &lt;span class="n"&gt;CART&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="n"&gt;item&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;item&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;CART&lt;/span&gt; &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;item&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;line_item_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;!=&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;line_item_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]]&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;removed&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;line_item_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;cart_size&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;len&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;CART&lt;/span&gt;&lt;span class="p"&gt;)}&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;checkout&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;accepted&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;yes&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;place the order&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;go ahead&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;confirm&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;buy it&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="nf"&gt;any&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;phrase&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;confirmation_phrase&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;lower&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;phrase&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;accepted&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
            &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;error&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;confirmation_unclear&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;phrase_received&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;confirmation_phrase&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]}&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ORD-9982&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;total&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;sum&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;i&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;price&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="n"&gt;i&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;quantity&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;i&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;CART&lt;/span&gt;&lt;span class="p"&gt;)}&lt;/span&gt;

    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;track_order&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;order&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;ORDERS&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;args&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;upper&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;order&lt;/span&gt; &lt;span class="ow"&gt;or&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;error&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;order_not_found&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;error&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;unknown_tool: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Step 3: Write a shopping-aware system prompt
&lt;/h2&gt;

&lt;p&gt;Shopping system prompts should encode three patterns: how to describe products on a phone (terse, scannable), how to gather variant info (size, color, quantity) before adding to cart, and how to confirm checkout.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;SYSTEM_PROMPT&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;
You are Riley, a friendly voice shopping assistant for Trailgear, an outdoor retailer.

Behavior rules:

PRODUCT SEARCH
- When customers ask about products, call search_products with a clean query.
- Read back top 2-3 results conversationally. Don&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;t list more than 3 unless asked.
- Format prices naturally: &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;one hundred thirty-nine dollars&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt; not &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;139.00&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.
- Mention only the most relevant detail per product (price + key feature). Save the rest for follow-ups.

VARIANT SELECTION
- Before adding to cart, confirm size, color, and quantity. Never assume.
- If a variant is out of stock, say so immediately and offer the closest alternative.
- Read sizes naturally: &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;size ten&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt; not &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;size 10&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;.

CART MANAGEMENT
- After adding, briefly confirm what was added and the new cart size.
- If the customer asks &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;what&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;s in my cart,&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt; call view_cart and read it back with subtotal.

CHECKOUT
- Before calling checkout, summarize the cart and explicitly ask: &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Should I place the order?&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;
- ONLY call checkout if the customer responds with a clear yes (e.g., &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;yes,&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt; &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;place it,&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt; &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;go ahead,&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt; &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;confirm&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;).
- If the response is ambiguous, ask again. Do not interpret &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;sure I think so&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt; as confirmation.
- After checkout succeeds, read back the order ID slowly so the customer can write it down.

ORDER TRACKING
- For order status questions, ask for the order ID.
- When reading a tracking number, slow down and group digits in pairs.

GENERAL
- Keep replies short and conversational. This is voice, not chat.
- When you call a tool, say a brief transition like &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Let me look that up.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;
- Never invent products, prices, or stock — if the catalog doesn&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;t have it, say so.
&lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The "explicit yes" pattern is what makes this safe to point at production payments. The agent's prompt forbids it from calling checkout on ambiguous responses, and the backend independently validates the confirmation phrase. Belt and suspenders.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 4: Wire the WebSocket
&lt;/h2&gt;

&lt;p&gt;This is essentially the same WebSocket loop as a support agent—the difference is in the tools and prompt, not the protocol. If you've already built a voice agent with function calling, this will look familiar.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;asyncio&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;base64&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;websockets&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;pyaudio&lt;/span&gt;

&lt;span class="n"&gt;API_KEY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getenv&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="n"&gt;WS_URL&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;wss://agents.assemblyai.com/v1/ws&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
&lt;span class="n"&gt;SAMPLE_RATE&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;24000&lt;/span&gt;

&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;run_assistant&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
    &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;with&lt;/span&gt; &lt;span class="n"&gt;websockets&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;connect&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="n"&gt;WS_URL&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;additional_headers&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Authorization&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Bearer &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;API_KEY&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="n"&gt;ws&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;ws&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;send&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dumps&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;session.update&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;session&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;system_prompt&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;SYSTEM_PROMPT&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;greeting&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Hi, this is Riley from Trailgear. What can I help you find today?&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;output&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;voice&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;mia&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tools&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;TOOLS&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;}))&lt;/span&gt;

        &lt;span class="n"&gt;pa&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;pyaudio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;PyAudio&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
        &lt;span class="n"&gt;mic&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;pa&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;open&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nb"&gt;format&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;pyaudio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;paInt16&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;channels&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;rate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;SAMPLE_RATE&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                      &lt;span class="nb"&gt;input&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;frames_per_buffer&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;1024&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="n"&gt;speaker&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;pa&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;open&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nb"&gt;format&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;pyaudio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;paInt16&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;channels&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;rate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;SAMPLE_RATE&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                          &lt;span class="n"&gt;output&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

        &lt;span class="n"&gt;ready&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;asyncio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;Event&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
        &lt;span class="n"&gt;pending_tools&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[]&lt;/span&gt;

        &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;send_audio&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
            &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;ready&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;wait&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
            &lt;span class="k"&gt;while&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                &lt;span class="n"&gt;data&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;mic&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;read&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1024&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;exception_on_overflow&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;False&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;ws&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;send&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dumps&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;input.audio&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;audio&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;base64&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;b64encode&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;data&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;decode&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
                &lt;span class="p"&gt;}))&lt;/span&gt;
                &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;asyncio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;sleep&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

        &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;handle_messages&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
            &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;raw&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;ws&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                &lt;span class="n"&gt;event&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;loads&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;raw&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

                &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;session.ready&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="n"&gt;ready&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;set&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
                    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Riley is ready.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;transcript.user&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="se"&gt;\n&lt;/span&gt;&lt;span class="s"&gt;Customer: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;text&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;transcript.agent&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Riley: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;text&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;reply.audio&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="n"&gt;speaker&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;write&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;base64&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;b64decode&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;data&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]))&lt;/span&gt;
                &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tool.call&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;  [tool] &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;(&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;arguments&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="si"&gt;{}&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;)&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
                    &lt;span class="n"&gt;result&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;run_tool&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;arguments&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{}))&lt;/span&gt;
                    &lt;span class="n"&gt;pending_tools&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;append&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;call_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;call_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;result&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;result&lt;/span&gt;&lt;span class="p"&gt;})&lt;/span&gt;
                &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;t&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;reply.done&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;status&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;interrupted&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                        &lt;span class="n"&gt;pending_tools&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;clear&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
                    &lt;span class="k"&gt;elif&lt;/span&gt; &lt;span class="n"&gt;pending_tools&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                        &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;tool&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;pending_tools&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                            &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;ws&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;send&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dumps&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
                                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;tool.result&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;call_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;tool&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;call_id&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
                                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;result&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;dumps&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;tool&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;result&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]),&lt;/span&gt;
                            &lt;span class="p"&gt;}))&lt;/span&gt;
                        &lt;span class="n"&gt;pending_tools&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;clear&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

        &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;asyncio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;gather&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nf"&gt;send_audio&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt; &lt;span class="nf"&gt;handle_messages&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;

&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;__name__&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;__main__&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="n"&gt;asyncio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;run&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nf"&gt;run_assistant&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Step 5: Test the four workflows
&lt;/h2&gt;

&lt;p&gt;Run the script and walk through each shopping flow:&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Search:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;You: "I'm looking for waterproof hiking boots under one fifty."
Riley: "Let me check our catalog... I've got the Trail Runner 3 at $139,
        which is waterproof and great for day hikes, and the Summit Pro
        at $199 — that's premium with extra ankle support. Want to hear
        more about either?"
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Add to cart:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;You: "The Trail Runner threes — size ten, in black."
Riley: "Got it, the Trail Runner 3 in black, size ten. How many?"
You: "Just one."
Riley: "One moment... Added. That's one item in your cart."
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Checkout:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;You: "Okay let's check out."
Riley: "Sure. You have one Trail Runner 3 in black, size ten, for $139.
        Should I place the order?"
You: "Yes, place it."
Riley: "Order placed. Your order ID is O-R-D 9-9-8-2."
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Track order:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;You: "Where's my order from last week — ORD 9-9-8-1?"
Riley: "Let me check... ORD-9981 has shipped and should arrive Friday,
        May 9th. Tracking is 1Z 99 9A A1 01 23 45 67 84."
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The tracking number readback is intentional—grouping digits in pairs is a common voice pattern that makes long alphanumerics easier to write down.&lt;/p&gt;

&lt;h2&gt;
  
  
  Where this gets harder in production
&lt;/h2&gt;

&lt;p&gt;Two patterns to plan for once the basic loop works:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Personalization.&lt;/strong&gt; Authenticated shoppers expect the agent to know their saved address, recent purchases, and size preferences. Add a get_customer_profile() tool gated on session auth. Use the result in the system prompt via mid-conversation session.update so the agent personalizes without re-asking.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Multi-turn refinement.&lt;/strong&gt; "Show me hiking boots" → "in waterproof" → "size ten only" → "under $150." Each refinement should narrow the same result set rather than triggering a fresh search. Pass a session_filters object as a tool parameter and have the agent accumulate filters across turns.&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Where to take it from here
&lt;/h2&gt;

&lt;p&gt;The same architecture extends to:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;In-store kiosks&lt;/strong&gt; for hands-free product search&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Phone-based ordering lines&lt;/strong&gt; for restaurants, takeout, and reorders (&lt;a href="https://www.assemblyai.com/docs/voice-agents/voice-agent-api/connect-to-twilio" rel="noopener noreferrer"&gt;Twilio Media Streams + the Voice Agent API Twilio integration&lt;/a&gt;)&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Mobile shopping apps&lt;/strong&gt; with a press-and-hold voice button&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Smart speaker integrations&lt;/strong&gt; that hand off to your agent when the user wants to shop&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;What stays the same across all of those: one WebSocket, one system prompt, one tool registry. The voice agent is the same regardless of the front-end channel.&lt;/p&gt;

&lt;p&gt;Voice shopping isn't replacing search bars or product pages—it's running alongside them, picking up the conversational moments those interfaces can't handle. Build for the conversational moments and the rest of your funnel benefits from it. For teams building AI-powered customer service workflows, the same voice agent architecture handles both pre-sale shopping and post-sale support.&lt;/p&gt;

&lt;h2&gt;
  
  
  Frequently asked questions
&lt;/h2&gt;

&lt;h3&gt;
  
  
  How do I build a voice-powered shopping assistant for e-commerce?
&lt;/h3&gt;

&lt;p&gt;Build it on AssemblyAI's Voice Agent API and register the four core shopping verbs as tools: search_products, add_to_cart, view_cart, and checkout. The agent transcribes the customer's speech, calls your catalog and cart functions, and speaks the result back—all on a single WebSocket. Most developers have a working voice shopping assistant running the same day, with no SDK to install and no separate STT, LLM, or TTS providers to manage.&lt;/p&gt;

&lt;h3&gt;
  
  
  Can a voice shopping assistant handle product variants like size, color, and quantity?
&lt;/h3&gt;

&lt;p&gt;Yes—define the variant fields as parameters on your add_to_cart tool (e.g., variant_id, quantity) and instruct the agent in the system prompt to confirm size, color, and quantity before calling the function. The Voice Agent API is built on Universal-3 Pro Streaming, which has industry-leading accuracy on alphanumeric tokens like sizes, SKUs, and quantities—that's what makes "size ten and a half" reliably parse as 10.5 instead of 10 or 1010.&lt;/p&gt;

&lt;h3&gt;
  
  
  How do I prevent accidental orders in a voice checkout flow?
&lt;/h3&gt;

&lt;p&gt;Use a two-layer pattern: the system prompt instructs the agent to only call the checkout tool after an explicit verbal "yes" to a clear confirmation prompt, and the checkout function itself accepts a confirmation_phrase parameter that your backend independently validates against an accepted list ("yes," "place the order," "go ahead," "confirm"). This belt-and-suspenders design ensures ambiguous responses like "sure I think so" never trigger a real charge.&lt;/p&gt;

&lt;h3&gt;
  
  
  What channels can I deploy a voice shopping assistant on?
&lt;/h3&gt;

&lt;p&gt;The same Voice Agent API connection powers in-app voice (mobile or web with a press-and-hold button), in-store kiosks for hands-free product search, phone-based ordering lines via Twilio Media Streams, and smart speaker integrations that hand off to your agent for shopping. The system prompt and tool registry stay the same across channels—only the front-end audio path changes.&lt;/p&gt;

&lt;h3&gt;
  
  
  How does the AssemblyAI Voice Agent API compare to Vapi or Retell for e-commerce?
&lt;/h3&gt;

&lt;p&gt;The Voice Agent API is infrastructure rather than a platform—it gives you a standard JSON WebSocket with full control over conversation design, tool integrations, and agent behavior, so your voice shopping experience can feel uniquely yours instead of like every other agent built on a no-code platform. Vapi and Retell are higher-level platforms that work well for non-technical configuration but constrain custom integrations and agent personality. For e-commerce teams that already have engineering capacity, the Voice Agent API is typically a better fit.&lt;/p&gt;

&lt;h3&gt;
  
  
  How do I personalize a voice shopping assistant for authenticated customers?
&lt;/h3&gt;

&lt;p&gt;Add a get_customer_profile tool that returns the customer's saved address, payment, recent purchases, and size preferences, gated on session auth. The Voice Agent API supports mid-conversation session.update events, so you can update the system prompt with the customer's context after they authenticate without dropping the connection. The agent can then personalize recommendations, default to known sizes, and skip questions like "what's your shipping address?"&lt;/p&gt;

&lt;h3&gt;
  
  
  How much does it cost to run a voice shopping assistant on AssemblyAI?
&lt;/h3&gt;

&lt;p&gt;The Voice Agent API is $4.50/hr flat-rate, covering STT, LLM, voice generation, turn detection, and tool calling on a single bill. There are no per-token surcharges, no concurrency caps, and no separate invoices for the STT, LLM, and TTS layers—pricing is billed by the minute on actual conversation duration. A free tier with $50 in starter credits is available for testing.&lt;/p&gt;

</description>
      <category>ai</category>
      <category>python</category>
      <category>tutorial</category>
      <category>ecommerce</category>
    </item>
    <item>
      <title>How to build an AI scribe for therapy sessions</title>
      <dc:creator>Mart Schweiger</dc:creator>
      <pubDate>Tue, 12 May 2026 17:57:52 +0000</pubDate>
      <link>https://dev.to/martschweiger/how-to-build-an-ai-scribe-for-therapy-sessions-39n1</link>
      <guid>https://dev.to/martschweiger/how-to-build-an-ai-scribe-for-therapy-sessions-39n1</guid>
      <description>&lt;p&gt;Therapy sessions are some of the hardest audio to scribe. Two people talking, often quietly, sometimes overlapping. Long therapeutic pauses that aren't end-of-turn. Clinical terminology mixed with informal speech. Medication names that sound like other medication names. PHI that absolutely cannot leak. And a clinician who needs to be present with their client—not typing.&lt;/p&gt;

&lt;p&gt;Most general-purpose transcription products fail at therapy because they were built for meetings or podcasts. Long pauses get treated as session ends. Mumbled mid-sentence corrections lose the original word. Drug names get mangled. And the post-session note-writing burden—DAP, SOAP, or BIRP format depending on the practice—still falls on the therapist.&lt;/p&gt;

&lt;p&gt;This tutorial walks through building a therapy-grade AI scribe that does three things well:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;
&lt;strong&gt;Ambient session capture&lt;/strong&gt; with Universal-3 Pro Streaming and Medical Mode, tuned for therapy-specific speech patterns&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Speaker-attributed transcripts&lt;/strong&gt; that distinguish therapist from client using speaker diarization&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Conversational note generation&lt;/strong&gt; with AssemblyAI's Voice Agent API—the clinician can dictate additions, ask questions about the session, and generate the formatted note all by voice&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;We'll cover HIPAA considerations throughout. AssemblyAI offers a Business Associate Agreement (BAA) for customers processing PHI, and is SOC 2 Type 2, ISO 27001:2022, and PCI DSS v4.0 certified. The architecture below is designed with PHI handling in mind—but a BAA is a contractual prerequisite for using this with real patient data.&lt;/p&gt;

&lt;h2&gt;
  
  
  The architecture
&lt;/h2&gt;

&lt;p&gt;Two phases, two AssemblyAI products, one continuous pipeline:&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Phase 1—During the session (ambient):&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Streaming speech-to-text captures the conversation with domain="medical-v1" (Medical Mode) and speaker_labels=true&lt;/li&gt;
&lt;li&gt;Tuned turn-detection settings prevent therapeutic pauses from triggering false end-of-turns&lt;/li&gt;
&lt;li&gt;Transcripts are buffered locally—never written to disk in plaintext outside the clinician's environment&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;Phase 2—After the session (conversational):&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;The clinician interacts with a Voice Agent API session that has the transcript loaded as context&lt;/li&gt;
&lt;li&gt;The agent can: read back specific moments, generate DAP/SOAP/BIRP notes, identify themes, suggest follow-ups, accept dictated additions&lt;/li&gt;
&lt;li&gt;Notes are produced as structured output and pushed to the EHR&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;The clinician never writes a note. They speak to the scribe.&lt;/p&gt;

&lt;h2&gt;
  
  
  What you'll build
&lt;/h2&gt;

&lt;p&gt;A Python prototype that:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Captures a live therapy session via microphone with Medical Mode and speaker diarization&lt;/li&gt;
&lt;li&gt;Persists a structured transcript with therapist/client roles&lt;/li&gt;
&lt;li&gt;Spins up a post-session Voice Agent that can answer questions about the session and generate a DAP note via tool call&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;&lt;strong&gt;Stack:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;AssemblyAI Universal-3 Pro Streaming with Medical Mode&lt;/li&gt;
&lt;li&gt;AssemblyAI Voice Agent API (post-session note generation)&lt;/li&gt;
&lt;li&gt;AssemblyAI LLM Gateway (structured note generation)&lt;/li&gt;
&lt;li&gt;Python 3.9
&lt;/li&gt;
&lt;/ul&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;pip &lt;span class="nb"&gt;install &lt;/span&gt;assemblyai websockets pyaudio python-dotenv requests

&lt;span class="c"&gt;# .env&lt;/span&gt;
&lt;span class="nv"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;your_key_here
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Before using with real PHI:&lt;/strong&gt; request a BAA from AssemblyAI, run the pipeline in your own controlled environment, and ensure the transcript persistence layer meets your organization's PHI requirements.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 1: Capture the session with Medical Mode
&lt;/h2&gt;

&lt;p&gt;The default streaming configuration is tuned for fast-paced voice agent dialogues. Therapy is the opposite—long therapeutic pauses are normal and meaningful. The Medical Mode docs recommend conservative turn detection settings for clinical audio: raise min_turn_silence to 800 ms and max_turn_silence to 3600 ms.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;
&lt;span class="kn"&gt;from&lt;/span&gt; &lt;span class="n"&gt;dotenv&lt;/span&gt; &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;load_dotenv&lt;/span&gt;
&lt;span class="kn"&gt;from&lt;/span&gt; &lt;span class="n"&gt;assemblyai.streaming.v3&lt;/span&gt; &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingClientOptions&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingParameters&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;BeginEvent&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;TurnEvent&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;TerminationEvent&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;StreamingError&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="nf"&gt;load_dotenv&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="n"&gt;API_KEY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;os&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getenv&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ASSEMBLYAI_API_KEY&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;# In-memory transcript buffer for the live session.
# In production: write to encrypted storage with PHI safeguards.
&lt;/span&gt;&lt;span class="n"&gt;session_transcript&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[]&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;on_begin&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;BeginEvent&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Session started: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nb"&gt;id&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;on_turn&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;TurnEvent&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;end_of_turn&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt;
    &lt;span class="n"&gt;speaker&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;speaker_label&lt;/span&gt; &lt;span class="ow"&gt;or&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;unknown&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
    &lt;span class="n"&gt;role&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Therapist&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt; &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;speaker&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;A&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt; &lt;span class="k"&gt;else&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Client&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
    &lt;span class="n"&gt;entry&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;role&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;text&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;transcript&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="n"&gt;session_transcript&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;append&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;entry&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;[&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;role&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;] &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;transcript&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;on_error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;error&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingError&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;STT error: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;error&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;on_terminated&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;event&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;TerminationEvent&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="nf"&gt;print&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Session ended. Total turns: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nf"&gt;len&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;session_transcript&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;start_session_capture&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;StreamingClient&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="nc"&gt;StreamingClientOptions&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
            &lt;span class="n"&gt;api_key&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;API_KEY&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="n"&gt;api_host&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;streaming.assemblyai.com&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;on&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;Begin&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;on_begin&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;on&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;Turn&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;on_turn&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;on&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;on_error&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;on&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;StreamingEvents&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;Termination&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;on_terminated&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="n"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;connect&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="nc"&gt;StreamingParameters&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
            &lt;span class="n"&gt;speech_model&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;u3-rt-pro&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="n"&gt;sample_rate&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;16000&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="n"&gt;domain&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;medical-v1&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="n"&gt;speaker_labels&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="n"&gt;min_turn_silence&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;800&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="n"&gt;max_turn_silence&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="mi"&gt;3600&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="n"&gt;keyterms_prompt&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;cognitive behavioral therapy&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;CBT&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;EMDR&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;GAD-7&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;PHQ-9&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;DSM-5&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;sertraline&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;fluoxetine&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;buspirone&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;panic attack&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;intrusive thought&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;client&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;A few details worth pointing out:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Medical Mode (domain="medical-v1") is purpose-built for clinical accuracy.&lt;/strong&gt; It corrects medication names like lisprohumalog to Lispro (Humalog)—the standard medical convention—and improves accuracy on procedures, conditions, and dosages. In therapy it covers SSRIs, common assessments, and DSM-5 terminology.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;speaker_labels=true&lt;/strong&gt; tags each turn with a speaker ID. With two-person therapy sessions, that maps cleanly to therapist (Speaker A) and client (Speaker B). For couples or family therapy, see the speaker identification docs for additional speakers.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;keyterms_prompt&lt;/strong&gt; boosts recognition for terms specific to your modality. For trauma practices, add EMDR-specific vocabulary; for psychiatric practices, add the medication formulary you actually prescribe.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;What you don't see here but matters in production: the transcript buffer should never persist outside an environment covered by your BAA. In-memory during the session, encrypted-at-rest after—and only if your storage layer meets your organization's PHI requirements.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 2: Add PII redaction for the persisted transcript
&lt;/h2&gt;

&lt;p&gt;For research, audit, or training purposes you may want to keep a redacted version of the session. AssemblyAI's PII redaction handles this for streaming transcripts. For pre-recorded post-session re-processing (if you want to go back and re-transcribe with higher-accuracy pre-recorded models), the redaction options are richer:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;requests&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;redact_post_session&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;audio_url&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;
    Re-process the recorded session audio with PII redaction
    and entity detection. Use this for the persisted record.
    &lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
    &lt;span class="n"&gt;response&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;requests&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;post&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;https://api.assemblyai.com/v2/transcript&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;headers&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;authorization&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;API_KEY&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;audio_url&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;audio_url&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;speech_models&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;universal-3-pro&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;universal-2&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;domain&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;medical-v1&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;speaker_labels&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;speakers_expected&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;redact_pii&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;redact_pii_policies&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;person_name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;date_of_birth&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;phone_number&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;email_address&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;us_social_security_number&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;credit_card_number&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="p"&gt;],&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;redact_pii_sub&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;hash&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;redact_pii_audio&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;    &lt;span class="c1"&gt;# Returns redacted audio URL with PII silenced
&lt;/span&gt;            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;entity_detection&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;response&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The redact_pii_audio: True flag returns a redacted version of the audio file with PII silenced—essential if you ever need to share clips for supervision or QA.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 3: Generate the DAP note with LLM Gateway
&lt;/h2&gt;

&lt;p&gt;DAP (Data, Assessment, Plan) is the dominant therapy note format in mental health practices, alongside SOAP and BIRP. LLM Gateway with structured outputs gives you predictable JSON output that maps directly into your EHR. The chat completions endpoint handles the request.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;requests&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;

&lt;span class="n"&gt;DAP_SCHEMA&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;data&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Objective observations from the session — what the client said, body language, presentation. No interpretation.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;assessment&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Clinical assessment — themes, progress toward goals, risk factors, response to interventions.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;plan&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Clinical plan — interventions used, homework assigned, next session focus.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;risk_flags&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;array&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;items&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Any safety concerns, suicidal/homicidal ideation, or escalations noted.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;themes&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;array&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;items&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2-4 short clinical themes (e.g. &lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;workplace anxiety&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;, &lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;sleep disruption&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;).&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;data&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;assessment&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;plan&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;risk_flags&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;themes&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;generate_dap_note&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;transcript&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;list&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="n"&gt;transcript_text&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="se"&gt;\n&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;entry&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;entry&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;text&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;entry&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;transcript&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="n"&gt;response&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;requests&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;post&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;https://llm-gateway.assemblyai.com/v1/chat/completions&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;headers&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;authorization&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;API_KEY&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;claude-sonnet-4-6&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;messages&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;system&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                    &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;You are an experienced clinical documentation assistant. &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;You generate DAP-format therapy notes from session transcripts. &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Be precise, professional, and clinically appropriate. &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Never invent information not present in the transcript. &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;If the transcript indicates risk (SI/HI, abuse, etc.), &lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
                        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;flag it explicitly in risk_flags.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
                    &lt;span class="p"&gt;),&lt;/span&gt;
                &lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;user&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Generate a DAP note for this session:&lt;/span&gt;&lt;span class="se"&gt;\n\n&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;transcript_text&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;],&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;response_format&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;json_schema&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;json_schema&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;dap_note&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;schema&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;DAP_SCHEMA&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;strict&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;True&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;fallbacks&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;gpt-5.1&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
                &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;model&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;gemini-2.5-pro&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="p"&gt;],&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;fallback_config&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;depth&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;json&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;loads&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;response&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;choices&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;message&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;content&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Three production-grade choices baked into this:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Structured output via JSON schema.&lt;/strong&gt; Guarantees the response shape—your EHR mapping code never has to parse freeform clinical text.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;fallbacks chain.&lt;/strong&gt; If the primary Claude model is overloaded, the Gateway transparently retries with GPT-5.1, then Gemini 2.5 Pro. A clinician finishing their day shouldn't have to wait or retry because of an upstream provider hiccup.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Explicit "never invent" instruction.&lt;/strong&gt; The single most important sentence in the system prompt. Without it, LLMs sometimes generate plausible-sounding but fabricated clinical content. With it, they leave fields shorter and more conservative.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;The note is generated. The clinician reviews. Nothing goes into the patient record without explicit approval—that's a non-negotiable design pattern for any AI medical scribe.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 4: Conversational scribe interaction with the Voice Agent API
&lt;/h2&gt;

&lt;p&gt;Now the part that makes this a true scribe rather than a transcription tool: after the session, the clinician opens a Voice Agent connection and just &lt;em&gt;talks&lt;/em&gt; to the scribe.&lt;/p&gt;

&lt;p&gt;The agent is configured with the session transcript loaded as system context, plus tools for the actions a therapist actually wants to take post-session: generate the note, search the transcript, add a dictated addendum, push to the EHR.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;SCRIBE_TOOLS&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;generate_dap_note&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Generate a DAP-format therapy note from the current session transcript.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{},&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[]},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;search_session&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Search the session transcript for what the client said about a topic.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;topic&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;topic&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;add_addendum&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Add a dictated addendum to the session note (e.g., a clinical observation the therapist remembered after the fact).&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;text&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;text&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;function&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;name&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;save_to_ehr&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;description&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Save the finalized note to the EHR. Only call after the clinician confirms.&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;parameters&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;object&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;properties&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;confirmation&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;type&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;string&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}},&lt;/span&gt;
            &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;required&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;confirmation&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The system prompt for the scribe agent:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;scribe_system_prompt&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;transcript&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;list&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="n"&gt;transcript_text&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="se"&gt;\n&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;e&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;role&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;e&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;text&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;e&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;transcript&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;&lt;span class="s"&gt;
You are a clinical documentation assistant for a licensed therapist. The therapist
just finished a session. Below is the session transcript.

Your role:
- Help the therapist generate, refine, and finalize the session note.
- Answer questions about what was said in the session.
- Accept dictated addenda.
- Never invent content that wasn&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;t in the session.
- Push to EHR ONLY when the therapist explicitly confirms.

Tone: professional, brief, never chatty. The therapist is between clients.

Session transcript:
---
&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;transcript_text&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;
---
&lt;/span&gt;&lt;span class="sh"&gt;"""&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;When the clinician finishes the session, they open the scribe Voice Agent connection. A natural interaction looks like:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;Therapist: "Generate the DAP note for this session."
Scribe:    "One moment... I have a draft. Want me to read it, or
            should I push it to the EHR?"
Therapist: "Read me the assessment section."
Scribe:    "Assessment: client reported continued anxiety triggered by
            workplace conflict, with a notable improvement in sleep over
            the past two weeks following sleep hygiene homework. Engaged
            well with cognitive restructuring exercise around catastrophic
            thinking. No safety concerns noted."
Therapist: "Add an addendum: client mentioned a possible elevation in
            symptoms after the meeting on Friday — flag for next session."
Scribe:    "Added. Anything else?"
Therapist: "Push it to the EHR."
Scribe:    "Confirming — should I save this note to the EHR?"
Therapist: "Yes, save it."
Scribe:    "Saved."
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The Voice Agent API connection is the same one we covered in the support and shopping tutorials—wss://agents.assemblyai.com/v1/ws, system prompt, tools, voice. The difference is that the system prompt carries the session transcript as context, and the tools are scribe-specific.&lt;/p&gt;

&lt;h2&gt;
  
  
  What this changes for therapists
&lt;/h2&gt;

&lt;p&gt;Three things, in order of how often clinicians mention them:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Eye contact comes back.&lt;/strong&gt; When the scribe is ambient and the note is generated by voice afterward, the therapist isn't typing during the session. Clients notice. Multiple ambient AI scribe deployments in adjacent specialties report patient engagement gains tied to therapists not staring at a screen.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;"Pajama time" goes away.&lt;/strong&gt; The hours of post-session note-writing—done at home after the kids are in bed—collapse into a five-minute review of an AI-drafted note. The Permanente Medical Group has reported thousands of physician hours saved at scale with ambient AI scribes; the same principle applies to mental health caseloads.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;The note quality is consistent.&lt;/strong&gt; Variability in note quality across a long day is real. An AI scribe writes the 11am note with the same care as the 5pm note.&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  What to harden before clinical use
&lt;/h2&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;BAA in place.&lt;/strong&gt; Do not run with real PHI without a Business Associate Agreement signed with AssemblyAI.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Encrypted transcript storage.&lt;/strong&gt; Session transcripts are PHI. Storage layer needs to match.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Clinician sign-off on every note.&lt;/strong&gt; AI-drafted, human-approved. No exceptions.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Audit trail.&lt;/strong&gt; Every note edit, addendum, and save-to-EHR action should be logged to a tamper-evident store.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Retention policy.&lt;/strong&gt; Document explicitly how long transcripts are kept, who can access them, and when they're deleted.&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Where to take it from there
&lt;/h2&gt;

&lt;p&gt;The same pattern extends to other formats—SOAP notes for primary care therapy referrals, BIRP for behavioral health, group therapy notes with multi-speaker diarization. Swap the schema, swap the keyterms, keep the architecture.&lt;/p&gt;

&lt;p&gt;For practices that want a single deployment:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Solo practitioners&lt;/strong&gt; can run the whole pipeline locally and push to a single EHR&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Group practices&lt;/strong&gt; can host the scribe centrally with per-clinician auth and route to multiple EHRs via the save_to_ehr tool&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Telehealth platforms&lt;/strong&gt; can wire the streaming STT into the existing call audio path with no change to the client-facing UI—an approach that works well for medical speech-to-text in virtual care settings&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;The architecture is the same. The integrations differ.&lt;/p&gt;

&lt;p&gt;The shape of clinical documentation is changing. The therapists who get the time back are the ones whose practices ship a scribe that actually works in their workflow—and the workflow is voice in, voice out, EHR-ready note in the middle.&lt;/p&gt;

&lt;h2&gt;
  
  
  Frequently asked questions
&lt;/h2&gt;

&lt;h3&gt;
  
  
  How do I build an AI scribe for therapy sessions?
&lt;/h3&gt;

&lt;p&gt;Build it as a two-phase pipeline: ambient session capture with AssemblyAI's Universal-3 Pro Streaming model in Medical Mode (domain="medical-v1") with speaker diarization, then post-session note generation through LLM Gateway with a structured JSON schema for DAP, SOAP, or BIRP format. The clinician interacts with the scribe conversationally through the Voice Agent API after the session—dictating addenda, asking questions about the transcript, and pushing the finalized note to the EHR by voice.&lt;/p&gt;

&lt;h3&gt;
  
  
  Does AssemblyAI support HIPAA workloads for therapy and clinical documentation?
&lt;/h3&gt;

&lt;p&gt;AssemblyAI offers a Business Associate Agreement (BAA) for customers processing Protected Health Information and is SOC 2 Type 2, ISO 27001:2022, and PCI DSS v4.0 certified. A BAA is a contractual prerequisite for using AssemblyAI with real PHI, including therapy session recordings, transcripts, and clinical notes. Contact AssemblyAI sales to start a BAA conversation before deploying into a regulated environment.&lt;/p&gt;

&lt;h3&gt;
  
  
  What is Medical Mode and why does it matter for therapy transcription?
&lt;/h3&gt;

&lt;p&gt;Medical Mode is an AssemblyAI add-on enabled with domain="medical-v1" that improves transcription accuracy for medical terminology—medication names, procedures, conditions, dosages, and clinical assessments. For therapy specifically, it correctly transcribes SSRIs (sertraline, fluoxetine), assessment instruments (GAD-7, PHQ-9), and DSM-5 terminology that general-purpose transcription models frequently mishear. It works with all of AssemblyAI's pre-recorded and streaming speech-to-text models.&lt;/p&gt;

&lt;h3&gt;
  
  
  How do I handle the long pauses common in therapy sessions without triggering false end-of-turns?
&lt;/h3&gt;

&lt;p&gt;Raise the streaming turn-detection thresholds—set min_turn_silence to 800 ms and max_turn_silence to 3600 ms (the conservative settings recommended in the Medical Mode docs). The default streaming configuration is tuned for fast-paced voice agent dialogues, which would incorrectly fragment therapeutic pauses into separate turns. With the conservative settings, clients can pause for several seconds to think without the system breaking the turn.&lt;/p&gt;

&lt;h3&gt;
  
  
  Can an AI scribe distinguish between therapist and client in a session recording?
&lt;/h3&gt;

&lt;p&gt;Yes—enable speaker diarization with speaker_labels=True and the streaming API will tag each turn with a speaker ID. For two-person therapy sessions, that maps cleanly to therapist (Speaker A) and client (Speaker B). For couples or family therapy with three or more speakers, AssemblyAI's Speaker Identification feature can identify speakers by their actual name or role.&lt;/p&gt;

&lt;h3&gt;
  
  
  What format should AI-generated therapy notes use—DAP, SOAP, or BIRP?
&lt;/h3&gt;

&lt;p&gt;DAP (Data, Assessment, Plan) is the dominant format in mental health practices, but SOAP and BIRP are also widely used depending on the modality and payer requirements. With LLM Gateway's structured output support, you define a JSON schema for the format you want and the model returns exactly that shape—making it trivial to switch between DAP, SOAP, and BIRP by swapping schemas. Whichever format you choose, the AI generates a draft and the clinician reviews and approves before anything goes into the patient record.&lt;/p&gt;

&lt;h3&gt;
  
  
  Can I redact PII from a therapy session transcript?
&lt;/h3&gt;

&lt;p&gt;Yes—enable PII redaction with redact_pii=True and specify the PII policies you want to detect (person names, dates of birth, phone numbers, email addresses, social security numbers, credit card numbers). For pre-recorded post-session re-processing, AssemblyAI also supports redact_pii_audio=True, which returns a redacted version of the audio file with PII silenced—useful if you ever need to share clips for clinical supervision or quality assurance.&lt;/p&gt;

&lt;h3&gt;
  
  
  How does an AI scribe interact with the clinician after the session?
&lt;/h3&gt;

&lt;p&gt;The clinician opens a Voice Agent API connection and talks to the scribe directly—saying things like "generate the DAP note," "read me the assessment section," "add an addendum: client mentioned elevation in symptoms after Friday's meeting," or "push it to the EHR." The agent has the session transcript loaded as system prompt context and tools registered for note generation, search, addenda, and EHR push, so the entire post-session documentation workflow happens by voice without typing.&lt;/p&gt;

</description>
      <category>ai</category>
      <category>python</category>
      <category>tutorial</category>
      <category>healthcare</category>
    </item>
    <item>
      <title>Master Golang: 5 Hands-on Labs for Constants, Control Flow, and Data Structures</title>
      <dc:creator>Labby</dc:creator>
      <pubDate>Tue, 12 May 2026 17:38:25 +0000</pubDate>
      <link>https://dev.to/labex/master-golang-5-hands-on-labs-for-constants-control-flow-and-data-structures-1ook</link>
      <guid>https://dev.to/labex/master-golang-5-hands-on-labs-for-constants-control-flow-and-data-structures-1ook</guid>
      <description>&lt;p&gt;Go is renowned for its simplicity and performance, but true mastery requires more than just reading documentation. To become a proficient Go developer, you must internalize how the language handles memory, data organization, and logic flow. This curated learning path provides a hands-on, interactive environment where you can write, test, and debug Go code directly in your browser, moving beyond theory into practical application.&lt;/p&gt;

&lt;h2&gt;
  
  
  Go Constants Fundamentals
&lt;/h2&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fog-image.labex.io%2Flabs%2Fgo-go-constants-fundamentals-149070" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fog-image.labex.io%2Flabs%2Fgo-go-constants-fundamentals-149070" alt="Go Constants Fundamentals" width="800" height="400"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Difficulty:&lt;/strong&gt; Beginner | &lt;strong&gt;Time:&lt;/strong&gt; 20 minutes&lt;/p&gt;

&lt;p&gt;Learn the essentials of constants in Go, including declaration, &lt;code&gt;iota&lt;/code&gt; usage, and best practices for defining immutable values in Go programming.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://labex.io/labs/go-go-constants-fundamentals-149070" rel="noopener noreferrer"&gt;Practice on LabEx →&lt;/a&gt; | &lt;a href="https://labex.io/tutorials/go-go-constants-fundamentals-149070" rel="noopener noreferrer"&gt;Tutorial →&lt;/a&gt;&lt;/p&gt;

&lt;h2&gt;
  
  
  If Branch Statement in Golang
&lt;/h2&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fog-image.labex.io%2Flabs%2Fgo-if-branch-statement-in-golang-149071" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fog-image.labex.io%2Flabs%2Fgo-if-branch-statement-in-golang-149071" alt="If Branch Statement in Golang" width="800" height="400"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Difficulty:&lt;/strong&gt; Beginner | &lt;strong&gt;Time:&lt;/strong&gt; 20 minutes&lt;/p&gt;

&lt;p&gt;Learn Go programming's if statement variations, including basic conditionals, else-if branches, initialization, and formatting techniques for effective control flow.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://labex.io/labs/go-if-branch-statement-in-golang-149071" rel="noopener noreferrer"&gt;Practice on LabEx →&lt;/a&gt; | &lt;a href="https://labex.io/tutorials/go-if-branch-statement-in-golang-149071" rel="noopener noreferrer"&gt;Tutorial →&lt;/a&gt;&lt;/p&gt;

&lt;h2&gt;
  
  
  Go Dictionary Fundamentals
&lt;/h2&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fog-image.labex.io%2Flabs%2Fgo-go-dictionary-fundamentals-149080" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fog-image.labex.io%2Flabs%2Fgo-go-dictionary-fundamentals-149080" alt="Go Dictionary Fundamentals" width="800" height="400"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Difficulty:&lt;/strong&gt; Beginner | &lt;strong&gt;Time:&lt;/strong&gt; 50 minutes&lt;/p&gt;

&lt;p&gt;Learn the essentials of Go dictionaries (maps), including declaration, initialization, manipulation, and iteration techniques for efficient key-value data management.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://labex.io/labs/go-go-dictionary-fundamentals-149080" rel="noopener noreferrer"&gt;Practice on LabEx →&lt;/a&gt; | &lt;a href="https://labex.io/tutorials/go-go-dictionary-fundamentals-149080" rel="noopener noreferrer"&gt;Tutorial →&lt;/a&gt;&lt;/p&gt;

&lt;h2&gt;
  
  
  Golang Slice Data Structures
&lt;/h2&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fog-image.labex.io%2Flabs%2Fgo-golang-slice-data-structures-149077" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fog-image.labex.io%2Flabs%2Fgo-golang-slice-data-structures-149077" alt="Golang Slice Data Structures" width="800" height="400"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Difficulty:&lt;/strong&gt; Beginner | &lt;strong&gt;Time:&lt;/strong&gt; 40 minutes&lt;/p&gt;

&lt;p&gt;Learn the fundamentals of Golang slices, exploring their structure, operations, and key techniques for efficient data manipulation and management.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://labex.io/labs/go-golang-slice-data-structures-149077" rel="noopener noreferrer"&gt;Practice on LabEx →&lt;/a&gt; | &lt;a href="https://labex.io/tutorials/go-golang-slice-data-structures-149077" rel="noopener noreferrer"&gt;Tutorial →&lt;/a&gt;&lt;/p&gt;

&lt;h2&gt;
  
  
  Array Operations in Golang
&lt;/h2&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fog-image.labex.io%2Flabs%2Fgo-array-operations-in-golang-149075" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fog-image.labex.io%2Flabs%2Fgo-array-operations-in-golang-149075" alt="Array Operations in Golang" width="800" height="400"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Difficulty:&lt;/strong&gt; Beginner | &lt;strong&gt;Time:&lt;/strong&gt; 35 minutes&lt;/p&gt;

&lt;p&gt;Learn essential array operations in Go, including initialization, traversal, element access, and understanding array characteristics in a practical, hands-on lab.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://labex.io/labs/go-array-operations-in-golang-149075" rel="noopener noreferrer"&gt;Practice on LabEx →&lt;/a&gt; | &lt;a href="https://labex.io/tutorials/go-array-operations-in-golang-149075" rel="noopener noreferrer"&gt;Tutorial →&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;Theory is only the beginning. By completing these five labs, you will have built a solid foundation in Go's core syntax and data management techniques. Whether you are preparing for a backend engineering role or building your first microservice, these hands-on exercises provide the muscle memory needed to write efficient, idiomatic Go code. Start your journey today and transform your understanding of the language through practice.&lt;/p&gt;

</description>
      <category>go</category>
      <category>programming</category>
      <category>tutorial</category>
      <category>backend</category>
    </item>
    <item>
      <title>Building Push Notifications in GusLift</title>
      <dc:creator>Abdul-Salam Zakaria</dc:creator>
      <pubDate>Tue, 12 May 2026 17:37:00 +0000</pubDate>
      <link>https://dev.to/guslift/building-push-notifications-in-guslift-iec</link>
      <guid>https://dev.to/guslift/building-push-notifications-in-guslift-iec</guid>
      <description>&lt;p&gt;GusLift connects student drivers with riders heading the same way. The matching itself happens over a WebSocket, which is fine when both people are staring at the app. The problem is that most of the time they aren't. Someone requests a ride, locks their phone, and the driver on the other side of campus has no idea anyone is waiting.&lt;/p&gt;

&lt;p&gt;This post walks through how push notifications were wired into GusLift across the three services that make up the product: the Expo mobile app, the Next.js backend on Cloudflare, and the matching worker (a Durable Object on Cloudflare Workers).&lt;/p&gt;

&lt;h2&gt;
  
  
  The shape of the problem
&lt;/h2&gt;

&lt;p&gt;There are exactly two moments where a push notification meaningfully changes user behavior:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;A driver picks a rider from the waiting list. The rider needs to know to open the app and accept.&lt;/li&gt;
&lt;li&gt;The rider accepts. The driver needs to know the ride is locked in.&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;Everything else, like seat counts updating or another driver joining the slot, is noise. Sending push for those would train users to ignore the notifications they actually need. So the scope was deliberately narrow: two event types, both tied to a confirmed action on the other side.&lt;/p&gt;

&lt;h2&gt;
  
  
  Architecture in one diagram
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;  mobile (Expo)                backend (Next.js)              matching-worker (DO)
  -------------                ----------------               --------------------
  registerCurrentUser     --&amp;gt;  POST /api/notifications/token
  PushToken()                  upsert into PushTokens
                                                              MatchingRoom event:
                                                                rider reserved
                                                                  or match accepted
                                                              --&amp;gt;  sendMatchPush
                                                                   Notification()
                                                                   reads PushTokens
                                                                   POST exp.host
  Notifications handler   &amp;lt;--  (Expo push service)            &amp;lt;--
  routes user to screen
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The mobile app owns token acquisition. The backend owns token storage. The matching worker owns dispatch. None of them know about the other two beyond a shared Supabase table and a stable contract on the wire.&lt;/p&gt;

&lt;h2&gt;
  
  
  The storage layer
&lt;/h2&gt;

&lt;p&gt;The whole feature hinges on one table:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight sql"&gt;&lt;code&gt;&lt;span class="k"&gt;create&lt;/span&gt; &lt;span class="k"&gt;table&lt;/span&gt; &lt;span class="n"&gt;if&lt;/span&gt; &lt;span class="k"&gt;not&lt;/span&gt; &lt;span class="k"&gt;exists&lt;/span&gt; &lt;span class="k"&gt;public&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nv"&gt;"PushTokens"&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
  &lt;span class="n"&gt;id&lt;/span&gt; &lt;span class="nb"&gt;bigint&lt;/span&gt; &lt;span class="k"&gt;generated&lt;/span&gt; &lt;span class="k"&gt;by&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="k"&gt;identity&lt;/span&gt; &lt;span class="k"&gt;primary&lt;/span&gt; &lt;span class="k"&gt;key&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;user_id&lt;/span&gt; &lt;span class="nb"&gt;text&lt;/span&gt; &lt;span class="k"&gt;not&lt;/span&gt; &lt;span class="k"&gt;null&lt;/span&gt; &lt;span class="k"&gt;references&lt;/span&gt; &lt;span class="k"&gt;public&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nv"&gt;"User"&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;on&lt;/span&gt; &lt;span class="k"&gt;delete&lt;/span&gt; &lt;span class="k"&gt;cascade&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;token&lt;/span&gt; &lt;span class="nb"&gt;text&lt;/span&gt; &lt;span class="k"&gt;not&lt;/span&gt; &lt;span class="k"&gt;null&lt;/span&gt; &lt;span class="k"&gt;unique&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;platform&lt;/span&gt; &lt;span class="nb"&gt;text&lt;/span&gt; &lt;span class="k"&gt;null&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;is_active&lt;/span&gt; &lt;span class="nb"&gt;boolean&lt;/span&gt; &lt;span class="k"&gt;not&lt;/span&gt; &lt;span class="k"&gt;null&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="k"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="nb"&gt;timestamp&lt;/span&gt; &lt;span class="k"&gt;without&lt;/span&gt; &lt;span class="nb"&gt;time&lt;/span&gt; &lt;span class="k"&gt;zone&lt;/span&gt; &lt;span class="k"&gt;not&lt;/span&gt; &lt;span class="k"&gt;null&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="n"&gt;now&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="n"&gt;updated_at&lt;/span&gt; &lt;span class="nb"&gt;timestamp&lt;/span&gt; &lt;span class="k"&gt;without&lt;/span&gt; &lt;span class="nb"&gt;time&lt;/span&gt; &lt;span class="k"&gt;zone&lt;/span&gt; &lt;span class="k"&gt;not&lt;/span&gt; &lt;span class="k"&gt;null&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="n"&gt;now&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="p"&gt;);&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;A few choices worth calling out:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;code&gt;token&lt;/code&gt; is unique, not &lt;code&gt;(user_id, token)&lt;/code&gt;. The same physical device could in theory be reused across user accounts (think shared family phone, or a dev account on a personal device), and we want the latest user to claim it. Upserts use &lt;code&gt;onConflict: "token"&lt;/code&gt; so the row gets reassigned cleanly instead of duplicating.&lt;/li&gt;
&lt;li&gt;
&lt;code&gt;is_active&lt;/code&gt; is a boolean rather than deleting rows. When Expo reports &lt;code&gt;DeviceNotRegistered&lt;/code&gt; we mark the row inactive. This keeps history useful for debugging "why didn't I get a push" complaints without leaking junk into the active set.&lt;/li&gt;
&lt;li&gt;A small &lt;code&gt;set_push_tokens_updated_at&lt;/code&gt; trigger keeps &lt;code&gt;updated_at&lt;/code&gt; honest on every write. Push tokens rotate, especially on iOS, so the freshness of a token row is something we look at when triaging.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Indexes are on &lt;code&gt;user_id&lt;/code&gt; and on &lt;code&gt;(user_id, is_active)&lt;/code&gt;. The hot read path is always "give me the active tokens for this one user," which the composite index covers.&lt;/p&gt;

&lt;h2&gt;
  
  
  Registering a token from the mobile app
&lt;/h2&gt;

&lt;p&gt;The mobile side lives in &lt;code&gt;mobile/lib/pushNotifications.js&lt;/code&gt;. It runs on app start and also whenever the app comes back to the foreground:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="nf"&gt;useEffect&lt;/span&gt;&lt;span class="p"&gt;(()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;registerCurrentUserPushToken&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;sub&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;AppState&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;addEventListener&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;change&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;state&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;state&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;active&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;registerCurrentUserPushToken&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;});&lt;/span&gt;
  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;sub&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;remove&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;
&lt;span class="p"&gt;},&lt;/span&gt; &lt;span class="p"&gt;[]);&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The "on resume" call matters more than it looks. Tokens can be revoked or rotated while the app is backgrounded (an OS update, a permission change, a reinstall), and Expo will hand back a different value next time you ask. Re-registering on foreground is the cheapest way to stay correct.&lt;/p&gt;

&lt;p&gt;The registration function itself is deliberately defensive. It walks through these steps and bails out loudly at any point that fails:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Skip on web entirely. There is no Expo push token there.&lt;/li&gt;
&lt;li&gt;Look up the user in &lt;code&gt;AsyncStorage&lt;/code&gt;. No stored &lt;code&gt;@user&lt;/code&gt;, no registration, since we'd have nowhere to attribute the token.&lt;/li&gt;
&lt;li&gt;On Android, create the &lt;code&gt;default&lt;/code&gt; notification channel with &lt;code&gt;MAX&lt;/code&gt; importance. Without this, notifications arrive but never make a sound or appear as a heads-up.&lt;/li&gt;
&lt;li&gt;Ask for permissions, requesting them if not already granted.&lt;/li&gt;
&lt;li&gt;Call &lt;code&gt;getDevicePushTokenAsync&lt;/code&gt; for logging, then &lt;code&gt;getExpoPushTokenAsync&lt;/code&gt; with the EAS &lt;code&gt;projectId&lt;/code&gt; from &lt;code&gt;Constants.expoConfig.extra.eas&lt;/code&gt;. The Expo token is what the backend actually stores.&lt;/li&gt;
&lt;li&gt;POST it to &lt;code&gt;${BACKEND_URL}/api/notifications/token&lt;/code&gt; with an &lt;code&gt;x-user-id&lt;/code&gt; header.&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;Every step logs a &lt;code&gt;[push] ...&lt;/code&gt; line. That has paid for itself many times over. When a user reports "I never got the notification," the first question is always "what does logcat say at app start," and the answer comes from these breadcrumbs.&lt;/p&gt;

&lt;p&gt;Sign-out goes through &lt;code&gt;deactivateCurrentUserPushToken&lt;/code&gt;, which calls &lt;code&gt;DELETE&lt;/code&gt; on the same endpoint. The server marks the row inactive rather than deleting it. If the device immediately signs back in we re-activate by upsert, no row churn.&lt;/p&gt;

&lt;h2&gt;
  
  
  The backend endpoint
&lt;/h2&gt;

&lt;p&gt;The token route is one file: &lt;code&gt;backend/app/api/notifications/token/route.ts&lt;/code&gt;. It exposes &lt;code&gt;POST&lt;/code&gt; and &lt;code&gt;DELETE&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;The auth story is intentionally simple. The handler accepts a user id in three ways, in this order:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;fromHeader&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;headers&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;x-user-id&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)?.&lt;/span&gt;&lt;span class="nf"&gt;trim&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;
&lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;fromHeader&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;fromHeader&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;bearer&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;parseAuthHeaderUserId&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;headers&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;Authorization&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;));&lt;/span&gt;
&lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;!&lt;/span&gt;&lt;span class="nx"&gt;bearer&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;bodyUserId&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nf"&gt;trim&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;// fall back to Supabase auth.getUser(bearer)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;code&gt;x-user-id&lt;/code&gt; is what the mobile app sends today because we already have a verified Google user id in &lt;code&gt;AsyncStorage&lt;/code&gt; after login. The &lt;code&gt;Authorization: Bearer ...&lt;/code&gt; path is there for when we move the rest of the API behind Supabase JWTs. Keeping both paths in one helper means we can flip the flag on auth without touching the notifications surface.&lt;/p&gt;

&lt;p&gt;The &lt;code&gt;POST&lt;/code&gt; body looks like:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight json"&gt;&lt;code&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="nl"&gt;"token"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"ExponentPushToken[...]"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="nl"&gt;"platform"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"ios"&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The handler normalizes both fields (trim, lowercase platform), then upserts on &lt;code&gt;token&lt;/code&gt;. That's the entire write path. The service role key lives in &lt;code&gt;SUPABASE_SERVICE_ROLE_KEY&lt;/code&gt;, since this endpoint needs to write across users without going through RLS.&lt;/p&gt;

&lt;p&gt;&lt;code&gt;DELETE&lt;/code&gt; is almost the same shape. If the body includes a specific token, only that row gets deactivated. If it doesn't, every active token for that user gets flipped off. The "deactivate all" variant is what runs on sign-out, so a shared device doesn't keep buzzing the previous user.&lt;/p&gt;

&lt;h2&gt;
  
  
  Dispatching from the matching worker
&lt;/h2&gt;

&lt;p&gt;The matching worker is a Cloudflare Durable Object. Each ride slot (location + day + start_time) is its own room, and inside that room there's a small state machine driving who is waiting, who is reserved, and who is confirmed. The push dispatch is hooked into exactly two transitions in &lt;code&gt;MatchingRoom.ts&lt;/code&gt;:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;shouldSendPush&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;driver_selected_rider&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;ev&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;rider_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;ev&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;driver_id&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;sendMatchPushNotification&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;env&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;recipientUserId&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;ev&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;rider_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;eventType&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;driver_selected_rider&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;riderId&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;ev&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;rider_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;driverId&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;ev&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;driver_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="p"&gt;});&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;and&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;shouldSendPush&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;rider_confirmed_match&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;ev&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;rider_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;ev&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;driver_id&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;sendMatchPushNotification&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;env&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;recipientUserId&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;ev&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;driver_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;eventType&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;rider_confirmed_match&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;riderId&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;ev&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;rider_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;driverId&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;ev&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;driver_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;rideId&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;ride&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="p"&gt;});&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Two things to notice. First, the call is fire and forget (&lt;code&gt;void&lt;/code&gt;). The state machine should never wait on Expo, and a failed push should never break a match. Second, &lt;code&gt;shouldSendPush&lt;/code&gt; gates every call.&lt;/p&gt;

&lt;h3&gt;
  
  
  Why dedupe is necessary
&lt;/h3&gt;

&lt;p&gt;Durable Objects can replay events. State recovery, client reconnects, even a rider rapidly tapping "accept" can cause the same logical transition to fire twice. Without dedupe, the user gets two identical notifications back-to-back, which feels broken even though it isn't.&lt;/p&gt;

&lt;p&gt;&lt;code&gt;shouldSendPush&lt;/code&gt; keeps an in-memory map keyed by &lt;code&gt;${slotKey}:${riderId}:${driverId}:${eventType}:${bucket}&lt;/code&gt;, where &lt;code&gt;bucket = floor(now / 30s)&lt;/code&gt;. Anything inside the same 30-second window for the same pair and event type is dropped. The map self-prunes anything older than 2 minutes, so it doesn't grow unbounded.&lt;/p&gt;

&lt;p&gt;This lives in the DO instance memory rather than Supabase. Cross-instance dedupe isn't needed because each slot only has one DO, and that DO is the only sender for the slot.&lt;/p&gt;

&lt;h3&gt;
  
  
  Talking to Expo
&lt;/h3&gt;

&lt;p&gt;&lt;code&gt;pushNotifications.ts&lt;/code&gt; in the worker is the actual sender. It does three things:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Fetch active tokens for the recipient out of &lt;code&gt;PushTokens&lt;/code&gt;. If a user has multiple devices, all of them get the message.&lt;/li&gt;
&lt;li&gt;Build a message per token and POST the array to &lt;code&gt;https://exp.host/--/api/v2/push/send&lt;/code&gt;. The payload sets &lt;code&gt;sound: "default"&lt;/code&gt;, a short human title and body, and stuffs the event metadata into &lt;code&gt;data&lt;/code&gt;.&lt;/li&gt;
&lt;li&gt;Walk the response tickets. Any token that comes back with &lt;code&gt;DeviceNotRegistered&lt;/code&gt; gets bulk-updated to &lt;code&gt;is_active = false&lt;/code&gt;.&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;The cleanup step is the part that's easy to forget. Without it, a user who reinstalls the app accumulates stale token rows, every push attempt eats a slot in the array sent to Expo, and you get rate-limited for ghosts. Treating &lt;code&gt;DeviceNotRegistered&lt;/code&gt; as a hint to deactivate keeps the active set healthy with zero ops work.&lt;/p&gt;

&lt;p&gt;The &lt;code&gt;data&lt;/code&gt; payload is the contract with the mobile app:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nl"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;params&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;eventType&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;            &lt;span class="c1"&gt;// "driver_selected_rider" | "rider_confirmed_match"&lt;/span&gt;
  &lt;span class="nx"&gt;rider_id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;params&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;riderId&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;driver_id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;params&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;driverId&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;ride_id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;params&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;rideId&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;            &lt;span class="c1"&gt;// present only on rider_confirmed_match&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Deep-linking from a tapped notification
&lt;/h2&gt;

&lt;p&gt;A push that just makes a sound is half a feature. The reason the data payload includes &lt;code&gt;type&lt;/code&gt; is so the mobile app can route the user to the correct screen when they tap the notification, instead of dropping them on the home screen.&lt;/p&gt;

&lt;p&gt;That listener lives in &lt;code&gt;mobile/app/_layout.js&lt;/code&gt;:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;subscription&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;Notifications&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;addNotificationResponseReceivedListener&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
  &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;response&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;response&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nx"&gt;notification&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nx"&gt;content&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="p"&gt;{};&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;type&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;typeof&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nx"&gt;type&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;string&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt; &lt;span class="p"&gt;?&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;type&lt;/span&gt; &lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;""&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;type&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;driver_selected_rider&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="nx"&gt;router&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;push&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;/rider/ScheduledRidesRider&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;type&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;rider_confirmed_match&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="nx"&gt;router&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;push&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;/driver/ScheduledRidesDriver&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;);&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;setNotificationHandler&lt;/code&gt; above it controls in-app behavior. We show the banner and the list entry, but don't play a sound or set a badge while the app is foregrounded. The reasoning is that if the user is already in the app, the WebSocket has already delivered the same information through the UI, and an extra sound on top of that is annoying.&lt;/p&gt;

&lt;h2&gt;
  
  
  How we fixed push notifications
&lt;/h2&gt;

&lt;p&gt;Everything above describes the design as if it landed clean. It didn't. The first end-to-end test had token registration logs that looked perfect, no notifications arriving on the Android device, and a matching flow that broke after a successful match (the rides screen rendered empty). What follows is the actual debug trail.&lt;/p&gt;

&lt;h3&gt;
  
  
  The five things that were broken
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;1. Wrong EAS project ownership.&lt;/strong&gt; The Expo project ID baked into &lt;code&gt;app.json&lt;/code&gt; belonged to an account I no longer had access to. &lt;code&gt;npx eas credentials&lt;/code&gt; returned &lt;code&gt;Entity not authorized&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;Fix: removed the old &lt;code&gt;extra.eas.projectId&lt;/code&gt;, ran &lt;code&gt;npx eas init&lt;/code&gt; to mint a fresh one under my account, rebuilt the app.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;2. Missing FCM credentials on the new Expo project.&lt;/strong&gt; Expo can issue an &lt;code&gt;ExponentPushToken[...]&lt;/code&gt; without FCM credentials, so registration looked fine, but &lt;code&gt;https://expo.dev/notifications&lt;/code&gt; returned &lt;code&gt;InvalidCredentials: Unable to retrieve the FCM server key&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;Fix: in Firebase Console under Project Settings, Service accounts, Generate new private key (not &lt;code&gt;google-services.json&lt;/code&gt;, that's a different file). Uploaded it via &lt;code&gt;npx eas credentials&lt;/code&gt;, Android, Google Service Account, FCM V1.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;3. Stale tokens from the old project still in the DB.&lt;/strong&gt; After re-creating the project, the old &lt;code&gt;ExponentPushToken[...]&lt;/code&gt; rows in &lt;code&gt;PushTokens&lt;/code&gt; were still &lt;code&gt;is_active = true&lt;/code&gt;. Mixing them with the new token in a single Expo batch made the whole send return 400.&lt;/p&gt;

&lt;p&gt;Fix: &lt;code&gt;delete from "PushTokens" where user_id = '...';&lt;/code&gt; then re-open the app to register a fresh token under the new project.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;4. Backend swallowed Expo's error reason.&lt;/strong&gt; &lt;code&gt;pushNotifications.ts&lt;/code&gt; only logged the status code, so 400s were opaque.&lt;/p&gt;

&lt;p&gt;Fix: added the response body and the token list to the error log so future push failures self-explain.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;5. Notification tap went to the wrong screen.&lt;/strong&gt; &lt;code&gt;_layout.js&lt;/code&gt; routed &lt;code&gt;driver_selected_rider&lt;/code&gt; to &lt;code&gt;ScheduledRidesRider&lt;/code&gt; (upcoming rides), not the accept/reject card.&lt;/p&gt;

&lt;p&gt;Fix: routed to &lt;code&gt;/rider/AvailableDrivers&lt;/code&gt; with &lt;code&gt;driverId&lt;/code&gt; from the push payload.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;6. Tap stacked a duplicate AvailableDrivers screen.&lt;/strong&gt; When the rider was already on &lt;code&gt;AvailableDrivers&lt;/code&gt; (because the in-app &lt;code&gt;match_request&lt;/code&gt; had already routed them there with full driver details), tapping the notification called &lt;code&gt;router.push&lt;/code&gt; again, pushing a second copy on top, hydrated only with &lt;code&gt;driverId&lt;/code&gt;, so it showed "Unknown Driver".&lt;/p&gt;

&lt;p&gt;Fix: added a &lt;code&gt;pathnameRef&lt;/code&gt; guard, skip the navigation if already on the target screen. Same guard for the driver-side &lt;code&gt;rider_confirmed_match&lt;/code&gt; notif.&lt;/p&gt;

&lt;h3&gt;
  
  
  Side bugs found and fixed along the way
&lt;/h3&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Empty upcoming-rides screen after accept.&lt;/strong&gt; Worker wrote &lt;code&gt;ride_date&lt;/code&gt; in UTC; backend queried in local time. Aligned the writer to use local-date components.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Rider showing 3x on driver's screen.&lt;/strong&gt; Rider's WS reconnects re-sent &lt;code&gt;rider_request&lt;/code&gt;, and &lt;code&gt;handleRiderRequest&lt;/code&gt; had no dedupe. Now ignored if the rider is already waiting or in a pending match.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;&lt;code&gt;INVALID_STATE_ERR&lt;/code&gt; from &lt;code&gt;MatchingContext.send&lt;/code&gt;.&lt;/strong&gt; The &lt;code&gt;?.&lt;/code&gt; only guarded null, not &lt;code&gt;CONNECTING&lt;/code&gt;/&lt;code&gt;CLOSING&lt;/code&gt; &lt;code&gt;readyState&lt;/code&gt;. Now checks &lt;code&gt;readyState === 1&lt;/code&gt;.&lt;/li&gt;
&lt;/ul&gt;

&lt;h3&gt;
  
  
  The actual checklist for end-to-end push
&lt;/h3&gt;

&lt;p&gt;Working backwards from the bug list, the requirements turned out to be:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Own the Expo project (account access).&lt;/li&gt;
&lt;li&gt;Upload an FCM V1 service-account key to it (so Expo can deliver to Android).&lt;/li&gt;
&lt;li&gt;Have a fresh, valid token registered in your DB.&lt;/li&gt;
&lt;li&gt;Have the server actually call the send (it was, the matching flow does).&lt;/li&gt;
&lt;li&gt;Route the tap somewhere useful, without stacking duplicate screens.&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;Items 1 and 2 are environmental and have nothing to do with the code. Items 3 through 5 are the ones the codebase has to keep honest forever. Most of the time when push "stops working" for a user later, the cause will be one of those three.&lt;/p&gt;

&lt;h2&gt;
  
  
  What it cost, what it bought
&lt;/h2&gt;

&lt;p&gt;In code, this feature is small. One SQL file, one Next.js route, one mobile lib, one worker module, and a handful of call sites in the existing matching room. The whole thing is a few hundred lines.&lt;/p&gt;

&lt;p&gt;What it bought is the ability to stop telling users "keep the app open while you wait." That single sentence was the biggest source of friction in early testing, and it didn't go away until tokens, dispatch, and dedupe were all in place.&lt;/p&gt;

&lt;p&gt;A few things would be worth picking up later:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Server-side dedupe at the Supabase layer would let us survive a DO restart without re-sending. Today the 30-second bucket protects the common cases but isn't bulletproof across instance churn.&lt;/li&gt;
&lt;li&gt;The &lt;code&gt;Authorization&lt;/code&gt; header path in the token route is wired up but not exercised. Moving the mobile client onto Supabase JWTs would let us drop &lt;code&gt;x-user-id&lt;/code&gt; and the trust assumption that goes with it.&lt;/li&gt;
&lt;li&gt;Right now the notification title and body strings are hardcoded in the worker. A small templating layer would make it cheaper to localize and to A/B test the copy.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;None of those block shipping. The current setup has been quietly delivering both event types reliably, deactivating dead tokens on its own, and routing taps to the correct screen, which is exactly the bar I wanted before writing about it.&lt;/p&gt;

</description>
      <category>mobile</category>
      <category>nextjs</category>
      <category>serverless</category>
      <category>tutorial</category>
    </item>
    <item>
      <title>Grant Reporting Best Practices - May 2026</title>
      <dc:creator>Rashmi Sheel</dc:creator>
      <pubDate>Tue, 12 May 2026 17:00:34 +0000</pubDate>
      <link>https://dev.to/rashmi_sheel_d64540cbec2d/grant-reporting-best-practices-may-2026-39df</link>
      <guid>https://dev.to/rashmi_sheel_d64540cbec2d/grant-reporting-best-practices-may-2026-39df</guid>
      <description>&lt;h3&gt;
  
  
  Introduction to Grant Reporting Best Practices
&lt;/h3&gt;

&lt;p&gt;As of May 2026, the grant landscape is becoming increasingly competitive, with organizations vying for a limited pool of funds to support their projects and initiatives. According to a recent report, the global grant management market is expected to reach $1.9 billion by 2028, growing at a compound annual growth rate (CAGR) of 13.4% during the forecast period. With this growth, the importance of effective grant reporting cannot be overstated. Grant reporting is a critical component of the grant management process, as it enables organizations to demonstrate their accountability, transparency, and stewardship of grant funds. In this article, we will explore grant reporting best practices, providing practical tips and actionable advice to help organizations optimize their grant reporting processes.&lt;/p&gt;

&lt;h3&gt;
  
  
  Understanding the Importance of Grant Reporting
&lt;/h3&gt;

&lt;p&gt;Grant reporting is not just a necessary evil; it is an opportunity for organizations to showcase their impact, build trust with funders, and demonstrate their capacity to manage grant funds effectively. A well-crafted grant report can help organizations:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Demonstrate their accountability and transparency in the use of grant funds&lt;/li&gt;
&lt;li&gt;Showcase their achievements and impact, highlighting the difference they are making in their community or field&lt;/li&gt;
&lt;li&gt;Build trust with funders, increasing the likelihood of future funding opportunities&lt;/li&gt;
&lt;li&gt;Identify areas for improvement, informing future project planning and implementation&lt;/li&gt;
&lt;/ul&gt;

&lt;h3&gt;
  
  
  Grant Reporting Best Practices
&lt;/h3&gt;

&lt;p&gt;So, what are the grant reporting best practices that organizations should adopt? Here are some key tips:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Start early&lt;/strong&gt;: Don't wait until the last minute to start working on your grant report. Begin gathering data and information as soon as the grant period commences.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Use a robust grant management system&lt;/strong&gt;: Invest in a grant management system that can help you track grant funds, monitor progress, and generate reports.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Be transparent and honest&lt;/strong&gt;: Be open and honest in your grant report, acknowledging challenges and setbacks, as well as successes and achievements.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Use data and metrics&lt;/strong&gt;: Use data and metrics to demonstrate your impact and progress, making it easier to tell your story and make your case for future funding.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Tell a story&lt;/strong&gt;: Use narrative techniques to bring your grant report to life, telling a story that showcases your organization's mission, vision, and values.&lt;/li&gt;
&lt;/ul&gt;

&lt;h3&gt;
  
  
  Actionable Advice for Grant Reporting
&lt;/h3&gt;

&lt;p&gt;In addition to these best practices, here are some actionable tips to help you optimize your grant reporting process:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Develop a grant reporting template&lt;/strong&gt;: Create a template that outlines the key information and data required for your grant report, making it easier to gather and organize information.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Establish a grant reporting schedule&lt;/strong&gt;: Set a schedule for grant reporting, ensuring that reports are submitted on time and that all stakeholders are informed and engaged.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Provide regular updates&lt;/strong&gt;: Provide regular updates to funders, keeping them informed of progress and milestones achieved during the grant period.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Conduct a thorough review&lt;/strong&gt;: Conduct a thorough review of your grant report before submission, ensuring that it is accurate, complete, and free of errors.&lt;/li&gt;
&lt;/ul&gt;

&lt;h3&gt;
  
  
  Leveraging Technology to Enhance Grant Reporting
&lt;/h3&gt;

&lt;p&gt;Technology can play a critical role in enhancing grant reporting, providing organizations with the tools and resources they need to streamline their grant management processes. For example, grant management software can help organizations:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Track grant funds&lt;/strong&gt;: Monitor grant funds, ensuring that they are used effectively and efficiently.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Generate reports&lt;/strong&gt;: Generate reports quickly and easily, using data and metrics to demonstrate impact and progress.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Collaborate with stakeholders&lt;/strong&gt;: Collaborate with stakeholders, including funders, team members, and partners, to ensure that everyone is informed and engaged.&lt;/li&gt;
&lt;/ul&gt;

&lt;h3&gt;
  
  
  Conclusion
&lt;/h3&gt;

&lt;p&gt;Grant reporting is a critical component of the grant management process, enabling organizations to demonstrate their accountability, transparency, and stewardship of grant funds. By adopting grant reporting best practices, organizations can optimize their grant reporting processes, building trust with funders and increasing the likelihood of future funding opportunities. To learn more about grant reporting best practices and how to optimize your grant management processes, businesses can learn more at: &lt;a href="https://flowgrant.ai" rel="noopener noreferrer"&gt;https://flowgrant.ai&lt;/a&gt;. With the right tools, resources, and expertise, organizations can harness the power of grant reporting to drive their mission forward, making a meaningful difference in their community or field. By staying up-to-date with the latest trends and best practices in grant reporting, organizations can ensure that they are well-positioned to succeed in an increasingly competitive grant landscape.&lt;/p&gt;




&lt;p&gt;Originally published at &lt;a href="https://flowgrant.ai" rel="noopener noreferrer"&gt;https://flowgrant.ai&lt;/a&gt;&lt;/p&gt;

</description>
      <category>business</category>
      <category>technology</category>
      <category>productivity</category>
      <category>tutorial</category>
    </item>
    <item>
      <title>Intelligent Automation Trends - May 2026</title>
      <dc:creator>Rashmi Sheel</dc:creator>
      <pubDate>Tue, 12 May 2026 17:00:21 +0000</pubDate>
      <link>https://dev.to/rashmi_sheel_d64540cbec2d/intelligent-automation-trends-may-2026-108a</link>
      <guid>https://dev.to/rashmi_sheel_d64540cbec2d/intelligent-automation-trends-may-2026-108a</guid>
      <description>&lt;h3&gt;
  
  
  Introduction to Intelligent Automation Trends
&lt;/h3&gt;

&lt;p&gt;As we navigate the ever-evolving landscape of technological advancements, intelligent automation has emerged as a pivotal force in transforming the way businesses operate. By harnessing the power of artificial intelligence (AI), machine learning (ML), and robotic process automation (RPA), organizations are streamlining processes, enhancing efficiency, and driving innovation. In May 2026, the intelligent automation trends are not only about adopting new technologies but also about creating a strategic framework that integrates these technologies seamlessly into existing infrastructures. This article delves into the current trends, offers practical tips, and provides actionable advice for businesses looking to leverage intelligent automation to their advantage.&lt;/p&gt;

&lt;h3&gt;
  
  
  Current State of Intelligent Automation
&lt;/h3&gt;

&lt;p&gt;The current state of intelligent automation is characterized by rapid growth and widespread adoption. According to recent statistics, the global intelligent automation market is projected to reach $15.8 billion by 2025, growing at a Compound Annual Growth Rate (CAGR) of 12.1% during the forecast period. This growth is largely driven by the need for businesses to automate repetitive and mundane tasks, improve operational efficiency, and enhance customer experience.&lt;/p&gt;

&lt;h3&gt;
  
  
  Key Trends in Intelligent Automation for May 2026
&lt;/h3&gt;

&lt;p&gt;Several trends are shaping the intelligent automation landscape in May 2026. Some of the key trends include:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;HyperAutomation&lt;/strong&gt;: This involves the use of advanced technologies like AI, ML, and RPA to automate complex processes that previously required human intervention. HyperAutomation is expected to revolutionize industries by providing unprecedented levels of automation and efficiency.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Autonomous Systems&lt;/strong&gt;: Autonomous systems, powered by AI and ML, are becoming increasingly prevalent. These systems can operate independently, making decisions in real-time without human intervention, thereby reducing the need for manual oversight.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Process Mining&lt;/strong&gt;: Process mining involves the use of data analytics and ML algorithms to discover, monitor, and improve business processes. This trend is gaining traction as it helps organizations identify areas where intelligent automation can be applied for maximum impact.&lt;/li&gt;
&lt;/ul&gt;

&lt;h3&gt;
  
  
  Practical Tips for Implementing Intelligent Automation
&lt;/h3&gt;

&lt;p&gt;Implementing intelligent automation requires a strategic approach. Here are some practical tips and actionable advice for businesses:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Assess Current Processes&lt;/strong&gt;: Begin by assessing your current business processes to identify areas that can be automated. Look for tasks that are repetitive, time-consuming, and prone to human error.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Choose the Right Technology&lt;/strong&gt;: Select technologies that align with your business goals and processes. Consider factors like scalability, integration capabilities, and user adoption.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Develop a Strategic Framework&lt;/strong&gt;: Create a strategic framework that outlines how intelligent automation will be integrated into your organization. This should include plans for training, implementation, and ongoing support.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Monitor and Evaluate&lt;/strong&gt;: Continuously monitor and evaluate the impact of intelligent automation on your business. Use data analytics to identify areas of improvement and make adjustments as needed.&lt;/li&gt;
&lt;/ul&gt;

&lt;h3&gt;
  
  
  Overcoming Challenges in Intelligent Automation
&lt;/h3&gt;

&lt;p&gt;While intelligent automation offers numerous benefits, it also presents several challenges. Some of the common challenges include:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Data Quality Issues&lt;/strong&gt;: Poor data quality can hinder the effectiveness of intelligent automation solutions. Ensure that your data is accurate, complete, and consistent.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Change Management&lt;/strong&gt;: Implementing intelligent automation requires significant changes to business processes and employee roles. Develop a comprehensive change management plan to mitigate resistance and ensure a smooth transition.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Security and Compliance&lt;/strong&gt;: Intelligent automation solutions must be designed with security and compliance in mind. Ensure that your solutions adhere to relevant regulations and standards.&lt;/li&gt;
&lt;/ul&gt;

&lt;h3&gt;
  
  
  Conclusion and Next Steps
&lt;/h3&gt;

&lt;p&gt;In conclusion, intelligent automation is transforming the business landscape by providing unprecedented levels of efficiency, innovation, and customer satisfaction. By understanding the current trends, adopting practical tips, and overcoming challenges, businesses can harness the power of intelligent automation to drive growth and success. For businesses looking to learn more about how to leverage intelligent automation, visiting &lt;a href="https://myassistant365.ai" rel="noopener noreferrer"&gt;https://myassistant365.ai&lt;/a&gt; can provide valuable insights and resources. This platform offers a wealth of information on the latest trends, technologies, and best practices in intelligent automation, helping organizations make informed decisions about their automation strategies. As we move forward in 2026, embracing intelligent automation will be crucial for businesses aiming to stay competitive and thrive in a rapidly evolving market.&lt;/p&gt;




&lt;p&gt;Originally published at &lt;a href="https://myassistant365.ai" rel="noopener noreferrer"&gt;https://myassistant365.ai&lt;/a&gt;&lt;/p&gt;

</description>
      <category>business</category>
      <category>technology</category>
      <category>productivity</category>
      <category>tutorial</category>
    </item>
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