OpenRouter provides developers with a single API endpoint that routes requests to over 300 language models from 60+ providers - including Anthropic, OpenAI, Google, Meta, and Mistral - using the OpenAI-compatible SDK. Instead of managing separate API keys, billing, and rate limits for each provider, you route everything through one interface and switch models by changing a parameter. The platform handles automatic fallback to backup providers when a model is down, fine-grained data policies to control which providers can process your prompts, and transparent token-level pricing across every model in the catalog. Developers building AI products use it to hedge against provider outages, benchmark models against each other, and optimize cost without changing their codebase. OpenRouter processes over 30 trillion tokens monthly across 5+ million global users. It's the default multi-model infrastructure layer for teams that want provider flexibility without the operational overhead.