What it is
OpenRouter is a gateway: the agent talks to one OpenAI-compatible endpoint and OpenRouter forwards each call to a provider of the model you named.
Strengths
- One endpoint and one bill for Anthropic, OpenAI, Google, Mistral, open models and more
- Routes to another provider of the same model when one fails, per its provider-routing docs
- OpenAI-compatible: works with any agent that accepts a custom base URL
Limits
- One more company sees your prompts
- An extra network hop on every call
Best for
- Trying several models without several accounts
- Fallback between providers
Not for
- Setups where a direct contract with the model provider is required
Our take
Our opinion: convenient for comparing models on your own tasks and for fallback, at the cost of one more party in the path of your prompts. If you settle on one model, a direct account with its provider removes that party; if you need fallback, OpenRouter is the simplest way to get it.
Sources
Read on 2026-10-27.
Alternatives
- Anthropic (Claude API): Anthropic's API for the Claude models, which several of the agents we follow were built around.
- OpenAI (GPT API): OpenAI's API for the GPT models. Its chat format is the one that OpenAI-compatible servers and gateways copy.