Enable structured output

How to configure structured output in Serverless Inference responses

Structured Output is similar to JSON mode but provides the added benefit of ensuring that the model’s response adheres to the schema you specify. We recommend using structured output instead of JSON mode when possible.

To enable structured output, specify json_schema as the response_format type in the request:

Python

import json
import openai

client = openai.OpenAI(
    base_url='https://api.inference.wandb.ai/v1',
    api_key="<your-api-key>",  # Create an API key at https://wandb.ai/settings
)

response = client.chat.completions.create(
    model="openai/gpt-oss-20b",
    messages=[
        {"role": "system", "content": "Extract the event information."},
        {"role": "user", "content": "Alice and Bob are going to a science fair on Friday."},
    ],
    response_format={
        "type": "json_schema",
        "json_schema": {
            "name": "CalendarEventResponse",
            "strict": True,
            "schema": {
                "type": "object",
                "properties": {
                    "name": {"type": "string"},
                    "date": {"type": "string"},
                    "participants": {"type": "array", "items": {"type": "string"}},
                },
                "required": ["name", "date", "participants"],
                "additionalProperties": False,
            },
        },
    },
)

content = response.choices[0].message.content
parsed = json.loads(content)
print(parsed)

Bash

curl https://api.inference.wandb.ai/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <your-api-key>" \
  -d '{
    "model": "openai/gpt-oss-20b",
    "messages": [
        {"role": "system", "content": "Extract the event information."},
        {"role": "user", "content": "Alice and Bob are going to a science fair on Friday."},
    ],
    "response_format": {
        "type": "json_schema",
        "json_schema": {
            "name": "CalendarEventResponse",
            "strict": True,
            "schema": {
                "type": "object",
                "properties": {
                    "name": {"type": "string"},
                    "date": {"type": "string"},
                    "participants": {"type": "array", "items": {"type": "string"}},
                },
                "required": ["name", "date", "participants"],
                "additionalProperties": False,
            },
        },
    },
  }'