Chat Completions

Request fields, response shape and streaming behaviour for POST /v1/chat/completions.

POST https://api.tokrouter.dev/v1/chat/completions
Authorization: Bearer sk-…
Content-Type: application/json

The most universal entry point: OpenAI protocol, and the default path for most clients and frameworks.

Request fields

Field	Type	Required	Notes
`model`	string	Yes	Model id, see Models
`messages`	array	Yes	Items have `role` (`system` / `user` / `assistant` / `tool`) and `content`
`stream`	boolean	No	`true` returns SSE, see Streaming
`max_tokens`	integer	No	Output token cap
`temperature`	number	No	Sampling temperature
`top_p`	number	No	Nucleus sampling
`stop`	string / array	No	Stop sequences
`tools`	array	No	Function declarations, see Tool calling
`tool_choice`	string / object	No	`auto` / `none` / a named function
`response_format`	object	No	Structured output, see Structured output
`user`	string	No	Caller-defined end-user identifier

A subset of the OpenAI protocol

The gateway interprets requests as OpenAI Chat Completions and maps them to the target vendor. Vendor-exclusive fields are not guaranteed — see Protocol bridging.

Response

{
  "id": "chatcmpl-...",
  "object": "chat.completion",
  "created": 1793000000,
  "model": "gpt-5.4-mini",
  "choices": [
    {
      "index": 0,
      "message": {"role": "assistant", "content": "Hello"},
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 12,
    "completion_tokens": 3,
    "total_tokens": 15
  }
}

usage.prompt_tokens_details.cached_tokens (when present) corresponds to the cache-read billed portion.

Streaming

With stream: true each chunk carries choices[0].delta and the stream ends with data: [DONE]. usage usually appears only in the final chunk, and some upstreams omit it entirely.

Status codes

Status	Meaning
`200`	Success (streaming also starts with 200; errors after the stream opens arrive as events)
`400`	Invalid body, e.g. unknown `model`
`401`	Authentication failure, see Authentication
`429`	Rate limit or quota cap
`5xx`	Upstream vendor error

Specific type / code values come from the upstream and are not enumerated here.

Request fields

Response

Streaming

Status codes

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