From Free Tier to Production: Building an App on One Multi-Model API

#ai #api #llm

Every LLM project follows the same arc: you start experimenting, you compare models, you pick one, you build, and then — if you're lucky — your token bill shows up like a surprise tax at the end of the month.

Here's how that whole journey looks on AIBridge, an OpenAI-compatible gateway in front of 15+ models, and why the "one endpoint" idea changes every step of it.

Step 1: Experiment for free, in the browser

Before writing a line of code, open the Playground and poke at models side by side. Same prompt, three models — you'll see the gap immediately:

deepseek-chat answers fast and cheap
kimi-k3 reasons through the hard ones
glm-4-plus sits somewhere in between No account needed, a few free requests a day. By the time you register, you already know which model your app wants.

Step 2: Register, get real quota, keep using the same key

Sign up and you get 500,000 tokens every month, reset automatically. No credit card, no trial countdown. Register with email or one-click GitHub login.

The switch from "playing in the playground" to "calling the API" is two lines:

from openai import OpenAI

client = OpenAI(
    base_url="https://aibridge-api.com/v1",
    api_key="mb-your-key",
)

resp = client.chat.completions.create(
    model="deepseek-chat",
    messages=[{"role": "user", "content": "Hello"}],
    stream=True,
)

You're already on the OpenAI SDK. Nothing new to learn.

Step 3: Let the app pick the model, not your code

The real payoff of a gateway is that model choice becomes data, not architecture. Cheap model for summaries, strong model for the hard 5%, embeddings through the same key:

def answer(q):
    model = "deepseek-chat" if len(q) < 500 else "kimi-k3"
    return client.chat.completions.create(model=model, messages=[{"role": "user", "content": q}])

Swap model by string, keep everything else. No per-provider SDKs, no vendor lock-in, no "we built on DeepSeek so we're stuck on DeepSeek."

Step 4: Scale without the surprise bill
When free quota runs out, the pricing is deliberately boring:

Top-up packs: 1M tokens 2.99⋅5M9.90 · 20M $29.90 — raw tokens, 1:1, no expiry, no multiplier games
Pro plan: $9.90/month for 5M monthly tokens + higher rate limits

Your balance and per-model usage live on one dashboard, so "which model is eating my budget" is a glance, not a spreadsheet excavation.

The two features you'll notice quietly

PII redaction — prompts get scanned and names/emails/phones are masked before they leave your app. Compliance without the build effort.
Failover & model health tracking — if a provider hiccups, traffic routes around it while you sleep.