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v1

latestOpenAPI 3.1.0Commercial2026-07-26232551.7 KB
Chat

Create a chat completion

OpenAI-compatible chat completions. Supports:

  • Streaming (stream: true, SSE)
  • Tool / function calling (tools, tool_choice)
  • Structured outputs (response_format)
  • Multimodal — send images via content: [{type: "image_url", ...}] (see ChatMessageContentPart schema below). https:// URLs work against every vision-capable model; OrcaRouter's translation layer adapts the content part for each upstream (OpenAI, Anthropic, Google, xAI Grok).
  • OrcaRouter fallback chains via extra_body.models.

Use provider-prefixed model names (openai/gpt-4o-mini, anthropic/claude-sonnet-4.6, google/gemini-2.5-flash), plain bare-name aliases when available, or named routers (orcarouter/auto).

post/chat/completions

Request body

modelstring required

Model ID. Supports three forms:

  • Provider-prefixed (default): openai/gpt-4o-mini, anthropic/claude-sonnet-4.6, google/gemini-2.5-flash
  • Plain alias: gpt-4o-mini (when a bare-name alias is available)
  • Named router: orcarouter/{name} (resolves to a model at request time; orcarouter/auto is seeded on signup for every account and picks the cheapest live chat model)
streamboolean

When true, response is streamed as server-sent events.

parallel_tool_callsboolean
temperaturenumber
top_pnumber
max_tokensinteger
max_completion_tokensinteger

Preferred over max_tokens for reasoning models.

ninteger
seedinteger

For deterministic sampling.

logprobsboolean
top_logprobsinteger
presence_penaltynumber
frequency_penaltynumber
logit_biasobject
userstring
reasoning_effort'low' | 'medium' | 'high'

For OpenAI reasoning models (o1, o3*, o4*, gpt-5*-pro, etc.). Anthropic Claude uses the thinking field instead; Gemini uses provider-specific configuration.

{"stackTrail":"components:schemas:ChatCompletionRequest:properties:web_search","oasType":"schema","type":"unknown","description":"Free-form raw payload forwarded to the upstream's web-search\ntool when `web_search_options` is not expressive enough.\nMost users should prefer `web_search_options`.\n"}

Example request

{
  "model": "gpt-4o",
  "messages": [
    {
      "content": [
        {
          "image_url": {
            "url": "https://example.com/photo.jpg"
          }
        }
      ]
    }
  ],
  "extra_body": {
    "models": [
      "openai/gpt-4o",
      "anthropic/claude-haiku-4.5",
      "google/gemini-2.5-pro"
    ]
  }
}

Response

Successful completion. Streaming responses use SSE (text/event-stream).

idstring
object'chat.completion'
createdinteger
modelstring

Example response

{
  "choices": [
    {
      "message": {
        "content": [
          {
            "image_url": {
              "url": "https://example.com/photo.jpg"
            }
          }
        ]
      }
    }
  ]
}