Gateway

Create chat completion

Creates a completion for the chat message.

post/chat/completions

Request

  • Base URL: https://api.phaseo.app/v1
  • URL: https://api.phaseo.app/v1/chat/completions
  • 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.

reasoning_effort'none' | 'instant' | 'minimal' | 'low' | 'medium' | 'high' | 'xhigh' | 'max'

OpenAI-compatible alias for reasoning.effort.

frequency_penaltynumber
logit_biasobject
max_completion_tokensinteger
max_tokensinteger
metadataobject
session_idstring

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

presence_penaltynumber
seedinteger
storeboolean
streamboolean
stream_optionsobject
temperaturenumber
max_tool_callsinteger
parallel_tool_callsboolean
logprobsboolean
top_logprobsinteger
top_pnumber
modalitiesstring[]
usageboolean
user_idstring
userstring
service_tier'standard' | 'default' | 'fast' | 'ultrafast' | 'priority' | 'flex' | 'batch'
prompt_cache_keystring nullable
safety_identifierstring nullable
metaboolean
echo_upstream_requestboolean

Example request

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

Response

Chat completion response

idstring
nativeResponseIdstring nullable
objectstring
createdinteger
modelstring
providerstring

Changes

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