Chat Completions

/v1/chat/completions is the OpenAI Chat Completions compatible entrypoint. OpenAI groups use the OpenAI-compatible path; other groups are converted by the gateway when supported.

Interface

Item	Value
Method	POST
Path	/v1/chat/completions
Content-Type	application/json
Authentication	Authorization: Bearer YOUR_API_KEY

Request Parameters

Parameter	Type	Required	Description
model	string	Yes	Requested model.
messages	array	Yes	OpenAI Chat Completions message array.
stream	boolean	No	Whether to stream the response.
temperature	number	No	Sampling temperature. Availability depends on the selected model.
max_tokens	integer	No	Maximum output tokens. Availability depends on the selected model.

Request Example

curl https://api.llmapi.site/v1/chat/completions \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "gpt-5.1",
    "messages": [
      { "role": "user", "content": "Hello" }
    ]
  }'

Response — 200 OK

{
  "id": "chatcmpl_123",
  "object": "chat.completion",
  "model": "gpt-5.1",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello."
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 12,
    "completion_tokens": 4,
    "total_tokens": 16
  }
}

When stream is true, the response uses OpenAI Chat Completions-compatible SSE chunks.

Compatible Path

Some clients use the path without /v1:

POST /chat/completions

This path points to the same gateway capability as /v1/chat/completions.

Errors

Status	Cause
400	Request body, model, or messages payload is invalid.
401	API key is missing or invalid.
403	Balance, quota, group, or subscription check failed.
404	Requested model or chat-compatible route is unavailable.
429	Rate limit or concurrency limit was reached.
500 / 502 / 503	Gateway or upstream provider failed.