OpenRouter

platform
https://openrouter.ai

OpenRouter aggregates language models from every major provider behind a single OpenAI-compatible API. Send requests to one endpoint, specify any model, and OpenRouter handles the rest — provider selection, rate limiting, and billing.

For agent systems, OpenRouter's killer feature is the models array: specify multiple models and the API automatically falls back to the next one if the first fails. Combined with provider routing (choosing the fastest or cheapest endpoint for a model), this gives your agents high availability without complex client-side logic.

The platform tracks usage across all models in one dashboard, making it easy to optimize costs and identify which models perform best for your use cases.

Key Features

  • 200+ models from all major providers
  • Native model fallback with models array
  • Provider routing for cost/latency optimization
  • Unified billing and usage tracking
  • OpenAI-compatible API format

Pros

  • +One API key for all models
  • +Built-in fallback routing
  • +Competitive pricing
  • +Great for multi-model systems

Cons

  • Additional latency from proxy layer
  • New features may lag behind direct APIs
  • Dependency on third-party service

In the Glossary