Orchestrator API
Create Chat Completion
Send a conversation to any Orchestrator API model using the OpenAI Chat Completions schema. Set stream: true to receive server-sent events; add stream_options: {"include_usage": true} to get token usage in the final chunk.
POST
Create Chat Completion
The Orchestrator API accepts the OpenAI Chat Completions schema, with a defined subset of parameters. Requests using an unsupported parameter fail with a
400 naming the parameter.Parameter support
Parameter support
Honored:
model, messages, stream, stream_options.include_usage, max_completion_tokens, max_tokens, temperature, top_p, stop, reasoning_effort, service_tier (auto, default, flex, priority), response_format (text, json_schema, json_object), tools, tool_choice (including allowed_tools), parallel_tool_calls, prompt_cache_key, prompt_cache_options, prompt_cache_retention, and message-part prompt_cache_breakpoint fields.Accepted but not forwarded to the model: user, safety_identifier, metadata.Accepted only at their default values: n (1), logprobs (false), store (false), presence_penalty (0), frequency_penalty (0).Rejected with a 400: seed, logit_bias, top_logprobs, functions (use tools), function_call (use tool_choice), modalities, audio, prediction, web_search_options, moderation, verbosity, stream_options.include_obfuscation set to true, plus any unrecognized top-level field.Notes: When reasoning_effort is omitted, the provider’s default for that model applies; defaults vary by provider and model. response_format.json_schema always runs in strict mode. Assistant messages and streamed deltas can include reasoning_content; replay it in an assistant message to preserve reasoning context across requests. Function tools require a description.Errors
Errors
Errors use the OpenAI envelope:
type is invalid_request_error for 4xx errors, rate_limit_error for 429 (rate limited or model overloaded — retry after the Retry-After interval), and server_error for 5xx. Requests that fail before producing output are not billed.Body
application/json
messages
(Developer message · object | System message · object | User message · object | Assistant message · object | Tool message · object | Function message · object)[]
required
The conversation so far, as an array of message objects with role and content. The leading system or developer message is applied as the system prompt.
Minimum array length:
1- Developer message
- System message
- User message
- Assistant message
- Tool message
- Function message
Response
Successful response. JSON for non-streaming requests; a text/event-stream of chat completion chunks terminated by data: [DONE] when stream is true.
Create Chat Completion