Create a message (Anthropic shape)
Anthropic Messages API-compatible endpoint. Accepts Anthropic's wire format; ModelBeat's own catalog-driven routing still decides which model actually serves the request — sending this shape does not pin you to an Anthropic-served model, and does not require one to exist in the catalog. Prompt-cache tokens (`cache_creation_input_tokens`/`cache_read_input_tokens`) are billed at the regular input rate, not Anthropic's cheaper cache-read rate.
Anthropic Messages API-compatible endpoint. Accepts Anthropic's wire format;
ModelBeat's own catalog-driven routing still decides which model actually serves the
request — sending this shape does not pin you to an Anthropic-served model, and does
not require one to exist in the catalog. Prompt-cache tokens
(cache_creation_input_tokens/cache_read_input_tokens) are billed at the regular
input rate, not Anthropic's cheaper cache-read rate.
Authorization
bearerAuth A ModelBeat API key, prefixed mb_live_, sent as Authorization: Bearer <key>.
Keys are issued in the ModelBeat console and are scoped to one tenant. The
example value used throughout this document
(mb_live_EXAMPLE_NOT_A_REAL_KEY_00000000000000000000) is a placeholder and
will not authenticate.
In: header
Header Parameters
Opaque, caller-chosen key that makes a retry safe. The OpenAI SDK — the integration path ModelBeat advertises — retries 5xx and timeouts by default; without this header each retry is a new logical request, i.e. a second reservation and a second charge for one prompt. Send the same key on a retry and ModelBeat returns the original reservation: one hold, one charge.
Reusing a key for a different request body, or one whose reservation was already settled,
is refused with 409. Keys longer than 255 characters are ignored (treated as absent).
length <= 255Request Body
application/json
TypeScript Definitions
Use the request body type in TypeScript.
Response Body
application/json
application/json
application/json
application/json
application/json
application/json
application/json
application/json
curl -X POST "https://example.com/messages" \ -H "Idempotency-Key: req-8f3a1c00-2b7e-4d9a-9c11-000000000000" \ -H "Content-Type: application/json" \ -d '{ "model": "auto", "max_tokens": 1, "messages": [ {} ] }'{}