Response Format

UNLI returns standardized responses based on the endpoint and format used.

OpenAI Format (`/v1/chat/completions`)

Standard Response

{
  "choices": [
    {
      "finish_reason": "stop",
      "index": 0,
      "message": {
        "content": "Hello! How can I help you today? 😊",
        "padding": "abcdefghijklmnopqrstuvwxyz",
        "role": "assistant"
      }
    }
  ],
  "id": "chatcmpl-BsUWgXcLO95QZEJsoaLdtj9HHf9sj",
  "usage": {
    "completion_tokens": 11,
    "prompt_tokens": 8,
    "prompt_tokens_details": {
      "cached_tokens": 0
    },
    "total_tokens": 19
  },
  "model": "auto",
  "system_fingerprint": "fp_07e970ab25"
}

Streaming Response

When stream: true, responses are sent as Server-Sent Events (SSE):

data: {"choices":[],"created":0,"id":""}

data: {"choices":[{"index":0,"delta":{"content":"","role":"assistant"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"index":0,"delta":{"content":"Hello"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"index":0,"delta":{"content":"!"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"index":0,"delta":{"content":" How"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"index":0,"delta":{"content":" can"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"index":0,"delta":{"content":" I"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"index":0,"delta":{"content":" help"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"index":0,"delta":{"content":" you"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"index":0,"delta":{"content":" today"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"index":0,"delta":{"content":"?"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"index":0,"delta":{"content":" 😊"}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","model":"auto","system_fingerprint":"fp_07e970ab25"}

data: {"choices":[{"finish_reason":"stop","index":0,"delta":{"content":null}}],"created":1752331931,"id":"chatcmpl-BsVsBmSED2kGgzlZFq9xLxNSkE03L","usage":{"completion_tokens":11,"prompt_tokens":9,"total_tokens":20},"model":"auto","system_fingerprint":"fp_07e970ab25"}

data: [DONE]

Anthropic Messages Format (`/v1/messages`)

Standard Response

{
  "id": "msg_01XFDUDYJgAACgrFtApKcNx3",
  "type": "message",
  "role": "assistant",
  "model": "unli-auto",
  "content": [
    {
      "type": "text",
      "text": "Hello! How can I assist you today?"
    }
  ],
  "stop_reason": "end_turn",
  "stop_sequence": null,
  "usage": {
    "input_tokens": 10,
    "output_tokens": 12
  }
}

Streaming Response (Anthropic SSE Events)

When stream: true, the API sends named events:

event: message_start
data: {"type":"message_start","message":{"id":"msg_01XFDUDYJgAACgrFtApKcNx3","type":"message","role":"assistant","content":[],"model":"unli-auto","stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":10,"output_tokens":1}}}

event: content_block_start
data: {"type":"content_block_start","index":0,"content_block":{"type":"text","text":""}}

event: content_block_delta
data: {"type":"content_block_delta","index":0,"delta":{"type":"text_delta","text":"Hello"}}

event: content_block_delta
data: {"type":"content_block_delta","index":0,"delta":{"type":"text_delta","text":"! How can I help you today?"}}

event: content_block_stop
data: {"type":"content_block_stop","index":0}

event: message_delta
data: {"type":"message_delta","delta":{"stop_reason":"end_turn","stop_sequence":null},"usage":{"output_tokens":12}}

event: message_stop
data: {"type":"message_stop"}

Error Responses

The API returns standard HTTP status codes and detailed error objects:

400 Bad Request

{
  "type": "error",
  "error": {
    "type": "invalid_request_error",
    "message": "Invalid request format or missing required fields"
  }
}

401 Unauthorized

{
  "type": "error",
  "error": {
    "type": "authentication_error",
    "message": "Invalid API key provided"
  }
}

429 Too Many Requests

{
  "type": "error",
  "error": {
    "type": "rate_limit_error",
    "message": "Rate limit exceeded. Please retry after some time."
  }
}

500 Internal Server Error

{
  "type": "error",
  "error": {
    "type": "api_error",
    "message": "An internal server error occurred"
  }
}

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