What an OpenAI-compatible API is
OpenAI-compatible means an endpoint speaks the same wire format as OpenAI’s chat completions API. Point any OpenAI client at it by changing the base URL, and your existing code works unchanged.
What compatibility covers
The shape of the request (model, messages, max_tokens, stream), the bearer-token auth, and the response and server-sent-event format. Redline serves https://redline-gateway.pages.dev/v1/chat/completions and https://redline-gateway.pages.dev/v1/models in this dialect.
What it does not cover
Not every OpenAI route Compatibility is about the chat completions surface. Redline does not serve /v1/responses, /v1/completions or /v1/embeddings. Tools that default to the Responses API (the Vercel AI SDK’s plain openai provider, n8n’s chat node) need to be told to use chat completions instead. The per-tool guides call this out.
Set it up
Set your client's base URL to https://redline-gateway.pages.dev/v1 and its key to your Redline key. See the Python, TypeScript and curl guides.