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Customer Support Agent with ADK and LangGraph

#agents #ai #fastapi #python

Customer Support Agent

Customer support agent via WhatsApp with Jira integration, built with Python, FastAPI, LangGraph, and Redis.

Architecture 

┌─────────────────┐     ┌─────────────────┐     ┌─────────────────┐
│    WhatsApp     │────▶│     FastAPI     │────▶│   AgentRunner   │
│   (Webhook)     │     │   /webhooks     │     │   (ADK Style)   │
└─────────────────┘     └─────────────────┘     └────────┬────────┘
│
▼
┌─────────────────┐     ┌─────────────────┐     ┌─────────────────┐
│      Redis      │◀───▶│   StateStore    │◀───▶│    LangGraph    │
│   (Sessions)    │     │                 │     │   StateGraph    │
└─────────────────┘     └─────────────────┘     └────────┬────────┘
│
┌───────────────┼───────────────┐
▼               ▼               ▼
┌────────────┐  ┌────────────┐  ┌────────────┐
│ CustomerDB │  │    Jira    │  │  Parsing   │
│   (Tool)   │  │   (Tool)   │  │  (Utils)   │
└────────────┘  └────────────┘  └────────────┘
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Conversational Flow 

[Customer] “Hi”
│
▼
[Agent] “Hi! To help you, please send me your CNPJ.”
│
▼
[Customer] “11.111.111/0001-91”
│
▼
[System] Validates CNPJ in the database
│
├─── Invalid CNPJ ──▶ “I couldn’t find an active account. Please confirm the number.”
│                           │
│                           └──▶ [Back to requesting CNPJ]
│
└─── Valid CNPJ ──▶ “Perfect! Tell me the product and describe your request.”
│
▼
[Customer] “Product: ERP, Request: error in the report”
│
▼
[System] Creates ticket in Jira
│
▼
[Agent] “✅ Request created: SUP-123”
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Requirements

  • Python 3.12+
  • Docker and Docker Compose
  • Poetry (dependency manager)

Installation

1. Clone the repository 

cd customer-support-agent
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  1. Install dependencies 
# Install Poetry (if needed)
curl -sSL https://install.python-poetry.org | python3 -
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Install dependencies 

poetry install
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  1. Configure environment variables

Create a .env file at the root of the project:

# Redis
REDIS_URL=redis://localhost:6379/0

# Jira
JIRA_BASE_URL=https://your-domain.atlassian.net
JIRA_EMAIL=your-email@example.com
JIRA_API_TOKEN=your-api-token
JIRA_PROJECT_KEY=SUP
JIRA_ISSUE_TYPE=Task

# WhatsApp (optional)
WHATSAPP_PROVIDER=cloudapi
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  1. Start the services

Start Redis and the application 

docker compose up -d

# Or start only Redis (for local development)
docker compose up -d redis

# Run the application locally
poetry run uvicorn app.main:app --reload --port 8000
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Usage

Testing with cURL 

# Health check
curl http://localhost:8000/health

# Simulate WhatsApp message - Greeting
curl -X POST http://localhost:8000/webhooks/whatsapp \
  -H "Content-Type: application/json" \
  -d '{"from":"+5511999999999","text":"hi"}'

# Send valid CNPJ
curl -X POST http://localhost:8000/webhooks/whatsapp \
  -H "Content-Type: application/json" \
  -d '{"from":"+5511999999999","text":"11111111000191"}'

# Send product and request
curl -X POST http://localhost:8000/webhooks/whatsapp \
  -H "Content-Type: application/json" \
  -d '{"from":"+5511999999999","text":"Product: ERP System, Request: error when generating report"}'
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bash

Valid CNPJs for testing (mock)

CNPJ Name Status
11111111000191 Demo Client Ltd. Active
22222222000191 Test Company S.A. Active
33333333000191 Inactive Company Inactive

API Endpoints

Method Endpoint Description
GET /health Health check
POST /webhooks/whatsapp Receives WhatsApp messages
GET /sessions/{phone} Retrieves session state
DELETE /sessions/{phone} Removes session

Tests

# Run all tests
poetry run pytest

# Run with coverage
poetry run pytest --cov=app

# Run a specific test
poetry run pytest tests/test_graph_flow.py -v
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Project Structure 

customer-support-agent/
├── app/
│   ├── main.py                    # FastAPI webhook
│   ├── settings.py                # Config via env vars
│   └── agent/
│       ├── runner.py              # AgentRunner (ADK style)
│       ├── graph.py               # LangGraph StateGraph
│       ├── state.py               # SupportState TypedDict
│       ├── nodes.py               # Node functions
│       ├── tools/
│       │   ├── customer_db.py     # Customer validation (mock)
│       │   └── jira.py            # Jira REST integration
│       └── utils/
│           ├── parsing.py         # CNPJ, product, request parsing
│           └── store.py           # Redis state store
├── tests/
│   └── test_graph_flow.py         # Flow tests
├── docker-compose.yml
├── Dockerfile
├── pyproject.toml
└── README.md
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Jira Configuration

Creating an API Token

  1. Go to https://id.atlassian.com/manage-profile/security/api-tokens
  2. Click “Create API token”
  3. Copy the token and add it to the .env

Creating the Project

  1. Create a project in Jira (e.g., “SUP” for Support)
  2. Configure the issue type (Task, Bug, etc.)
  3. Update the variables JIRA_PROJECT_KEY and JIRA_ISSUE_TYPE

WhatsApp Integration

WhatsApp Cloud API

Configure the webhook URL in Meta Business:

https://your-domain.com/webhooks/whatsapp
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Twilio

Configure the webhook URL in the Twilio Console:

https://your-domain.com/webhooks/whatsapp
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Repository URL

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