OpenRouter Has a Free API: One API Key for Every AI Model

#ai #api #openai #programming

Managing API keys for OpenAI, Anthropic, Google, Mistral, Meta — it's a mess. OpenRouter gives you one key for all of them.

What Is OpenRouter?

OpenRouter is a unified API that routes your requests to 200+ AI models from every major provider. One API key. One format. OpenAI-compatible.

import openai

client = openai.OpenAI(
    base_url="https://openrouter.ai/api/v1",
    api_key="your-openrouter-key"
)

# Use ANY model with the same code
response = client.chat.completions.create(
    model="anthropic/claude-sonnet-4",  # or "openai/gpt-4o" or "google/gemini-2.0-flash"
    messages=[{"role": "user", "content": "Hello!"}]
)

Switch models by changing one string. No SDK changes. No code changes.

Free Models

OpenRouter offers several free models:

google/gemma-2-9b-it:free
mistralai/mistral-7b-instruct:free
meta-llama/llama-3.1-8b-instruct:free
qwen/qwen-2.5-7b-instruct:free

Free tier with rate limits — enough for prototyping.

Model Routing

# Auto-select the best model for your task
response = client.chat.completions.create(
    model="openrouter/auto",  # OpenRouter picks the best model
    messages=[{"role": "user", "content": "Explain quantum computing"}]
)

# Fallback chains — if one model fails, try the next
response = client.chat.completions.create(
    model="anthropic/claude-sonnet-4",
    extra_body={
        "route": "fallback",
        "models": ["anthropic/claude-sonnet-4", "openai/gpt-4o", "google/gemini-2.0-flash"]
    },
    messages=[{"role": "user", "content": "Hello"}]
)