Gateway

Create message

Creates a message using the Anthropic Messages API.

post/messages

Request

  • Base URL: https://api.phaseo.app/v1
  • URL: https://api.phaseo.app/v1/messages
  • Auth: HTTP bearer

Request body

modelstring required
modelsstring[]

Optional ordered fallback models tried after model. model is required and is always the primary model. When an attempt fails with 429, 500, 502, 503, or 504, the next entry is tried; other errors are returned unchanged. Accepts up to 25 model IDs or presets; duplicates and entries equal to model are ignored. Each attempt is validated, logged, and billed as its own request, and the response model field and routing trace show the model that served the request. Streaming requests fall back only before the first byte, and video and music jobs fall back only at submission. Batch, realtime, and council requests reject models. Fallbacks set on a dynamic route take precedence, and phaseo/auto cannot be combined with models.

max_tokensinteger required
service_tier'standard' | 'default' | 'fast' | 'ultrafast' | 'priority' | 'flex' | 'batch'

Selects a supported routing or pricing tier on compatible text APIs.

temperaturenumber
top_pnumber
top_kinteger
streamboolean
metadataobject
session_idstring

Unique identifier for grouping related requests (for example, a conversation or agent workflow) for observability.

stop_sequencesstring[]
usageboolean
metaboolean
echo_upstream_requestboolean

Example request

{
  "models": [
    "anthropic/claude-sonnet-5-5",
    "google/gemini-2.5-flash"
  ]
}

Response

Message response

idstring
typestring
role'assistant'
modelstring
stop_reasonstring
stop_sequencestring

Changes

No recorded changes to this operation across all 1 revision of this API.