How OpenRouter Model Routing Works

If Anthropic rate-limits you mid-traffic, your app shouldn’t return a 500. That single failure mode is a big reason teams reach for an LLM router in the first place. OpenRouter routes every request across 70+ providers, and you control how, down to the provider order, the price ceiling, and the fallback chain. Routing in OpenRouter is 2 independent decisions: which model answers the request and which provider serves that model. Every configuration option in this guide maps to one of those 2 decisions. Keeping them separate is what lets you configure the right layer when something breaks. The OpenRouter Python SDK (pip install openrouter) gets you there in a few lines, and switching models is a one-string change. (Already on the OpenAI SDK? Point its base URL at https://openrouter.ai/api/v1 and it works too.) That’s the whole integration. The routing happens behind that one endpoint, and the rest of this guide works through the routing layers it exposes, with the exact config you copy in. Those 2 decisions sit inside a bigger job. A router takes one request to one endpoint and handles the handoff to whatever model and provider should answer it. Every router does 4 of these jobs, and…