Chat Completions - airmux

POST /inf/v1/chat/completions

This route always accepts and returns OpenAI Chat Completions. Headers and request-body fields cannot select another caller protocol.

Request

curl https://llm.example.com/inf/v1/chat/completions \
  -H "Authorization: Bearer $AIRMUX_INFERENCE_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "openai/gpt-4o-mini",
    "messages": [{"role": "user", "content": "Say hello"}],
    "max_completion_tokens": 128
  }'

Core fields

Field	Type	Notes
`model`	string	Required catalog model ID
`messages`	array	System, developer, user, assistant, and tool messages
`stream`	boolean	Defaults to `false`
`max_tokens`	integer	Legacy Chat Completions spelling; minimum 1
`max_completion_tokens`	integer	Current Chat Completions spelling; minimum 1
`temperature`	number	Minimum 0
`top_p`	number	Greater than 0 and at most 1
`stop`	string or array	Normalized to an array
`seed`	integer	Forwarded when supported
`tools`	array	Function tools
`tool_choice`	string or object	`auto`, `none`, `required`, or a named function
`parallel_tool_calls`	boolean	Requires provider support when supplied
`response_format`	object	`text`, `json_object`, or `json_schema`
`reasoning_effort`	string	Folded into canonical reasoning configuration
`reasoning`	object	Extended reasoning configuration

Other top-level fields are treated as provider extras. A provider profile either forwards them or reports them as dropped in gateway.adjustments. Supplying both output-limit fields is invalid. Either field maps to canonical max_output_tokens.

Response

{
  "id": "019...",
  "object": "chat.completion",
  "created": 1789000000,
  "model": "openai/gpt-4o-mini",
  "choices": [
    {
      "index": 0,
      "message": {"role": "assistant", "content": "Hello!"},
      "finish_reason": "stop"
    }
  ],
  "usage": {"prompt_tokens": 8, "completion_tokens": 2, "total_tokens": 10},
  "gateway": {"finish_reason": "stop", "adjustments": []}
}

finish_reason is one of stop, length, tool_calls, or content_filter when present.

Streaming

Streaming returns Chat Completions SSE chunks, a terminal choice carrying finish_reason, a usage-only chunk with choices: [] and gateway, then data: [DONE]. Usage is always included even if the caller omits stream_options.