OpenRouter

A unified API gateway that provides access to hundreds of AI models (open-source and proprietary) through a single OpenAI-compatible endpoint. Includes many free models and a model ranking/comparison interface.

Use with Claude Code

Configure Claude Code to route requests through OpenRouter instead of Anthropic’s API. Enables access to free and cheap models without running anything locally.

Key configuration (.claude/settings.local.json):

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://openrouter.ai/api/v1",
    "ANTHROPIC_AUTH_TOKEN": "<your-openrouter-api-key>",
    "ANTHROPIC_MODEL": "<model-id>:free",
    "ANTHROPIC_SMALL_FAST_MODEL": "<model-id>:free"
  }
}

Critical: Set ALL model env vars. Omitting ANTHROPIC_SMALL_FAST_MODEL causes Claude Code to silently fall back to paid Anthropic Haiku/Sonnet for small tool calls.

Get your API key from: openrouter.ai → Credits → API Keys.

Free Model Tier

• Append :free to any free model’s ID
• OpenRouter also offers a free router (openrouter/auto) that dynamically selects the most available free model
• Rate limits: 50 requests/day with no deposit; 1,000 requests/day with any deposit ($5+)
• Free models still cost $0 even with a deposit — the deposit only unlocks rate limits

Model Discovery

OpenRouter’s website shows rankings by category (programming, reasoning, etc.) with ELO scores and pricing. Useful for comparing open-source and proprietary models side by side.

Trade-Offs vs Local (Ollama)

	OpenRouter	Local (Ollama)
Privacy	Data leaves your machine	Fully local
Speed	Fast (cloud inference)	Depends on hardware
Cost	Free or very cheap	Hardware cost
Model quality	Access to large models	Capped by local RAM/GPU

See Also

• Claude Code
• Ollama
• Open-Source Model Integration