Chat With Structured Outputs

Chat with Structured Outputs

post

Generate structured JSON responses that conform to a specific schema, ensuring predictable and reliable data formats for your applications.

Header parameters

AuthorizationstringRequiredExample: sk-lZxz8

Body

modelstringRequired

Responses

200Success

application/json

idstringRequired

modelstringRequired

objectstringRequired

createdintegerRequired

request_idstringRequired

post/v1/chat/completions

POST /v1/chat/completions HTTP/1.1
Host: llm.onerouter.pro
Authorization: text
Content-Type: application/json
Accept: */*
Content-Length: 528

{
  "model": "openai/gpt-5.4",
  "messages": [
    {
      "role": "user",
      "content": "What's the weather like in London?"
    }
  ],
  "response_format": {
    "type": "json_schema",
    "json_schema": {
      "name": "weather",
      "strict": true,
      "schema": {
        "type": "object",
        "properties": {
          "location": {
            "type": "string",
            "description": "City or location name"
          },
          "temperature": {
            "type": "number",
            "description": "Temperature in Celsius"
          },
          "conditions": {
            "type": "string",
            "description": "Weather conditions description"
          }
        },
        "required": [
          "location",
          "temperature",
          "conditions"
        ],
        "additionalProperties": false
      }
    }
  }
}

200Success

{
  "id": "chatcmpl-DL28X0Shp6uFdggB0HWMDJDePQj1t",
  "model": "openai/gpt-5.4",
  "object": "chat.completion",
  "created": 1773905473,
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "{\"conditions\":\"Cloudy\",\"location\":\"London\",\"temperature\":12}"
      },
      "finish_reason": "stop",
      "logprobs": null
    }
  ],
  "request_id": "386e633a3c254d5a8940d73645b7bb90",
  "usage": {
    "prompt_tokens": 71,
    "completion_tokens": 21,
    "total_tokens": 92,
    "prompt_tokens_details": {
      "cached_tokens": 0,
      "cache_write_tokens": 0,
      "audio_tokens": 0,
      "video_tokens": 0
    },
    "completion_tokens_details": {
      "reasoning_tokens": 0,
      "image_tokens": 0,
      "audio_tokens": 0
    }
  }
}