Create Message
Messages
Create Message
Anthropic-compatible Messages endpoint.
Auth: x-api-key: rsk_<ULID> (or Authorization: Bearer rsk_<ULID>)
Models: any model this gateway serves, not only Anthropic's
Streaming: set stream=true for Anthropic SSE events
POST
Create Message
Authorizations
Enter your MeshAPI key (rsk_...) — sent as Authorization: Bearer <key>.
Headers
Dated version of the API contract to pin this request to. Omit it and the request is served under 2026-08 — the oldest supported version, so an existing integration is never moved by a release. A malformed or unsupported value is rejected with 400 invalid_api_version rather than falling back silently. The version actually served is echoed as X-Mesh-Version on every response, including errors.
Available options:
2026-08 Body
application/json
Required range:
x >= 1Required range:
0 <= x <= 1Required range:
0 <= x <= 1Response
Successful Response