Create formatted output

POST

/v1/messages

Given a hint, the model will return one or more complete predictions, and may also return the probability of an alternative label at each location.

Complete creation for the provided hint and parameters

Official documentation: https://docs.anthropic.com/en/docs/agents-and-tools/tool-use/overview#how-tool-use-works

Request

Authorization

Bearer Token

Provide your bearer token in the

Authorization

header when making requests to protected resources.

Example:

Authorization: Bearer ********************

Header Params

Body Params application/json

Examples

Responses

🟢200

application/json

Body

Request Example

Shell

JavaScript

Java

Swift

curl --location --request POST '/v1/messages' \
--header 'Accept: application/json' \
--header 'anthropic-beta: structured-outputs-2025-11-13' \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data-raw '{
    "model": "claude-sonnet-4-5-20250929",
    "max_tokens": 1024,
    "messages": [
        {
            "role": "user",
            "content": "Extract the key information from this email: John Smith (john@example.com) is interested in our Enterprise plan and wants to schedule a demo for next Tuesday at 2pm."
        }
    ],
    "output_format": {
        "type": "json_schema",
        "schema": {
            "type": "object",
            "properties": {
                "name": {
                    "type": "string"
                },
                "email": {
                    "type": "string"
                },
                "plan_interest": {
                    "type": "string"
                },
                "demo_requested": {
                    "type": "boolean"
                }
            },
            "required": [
                "name",
                "email",
                "plan_interest",
                "demo_requested"
            ],
            "additionalProperties": false
        }
    }
}'

Response Example

{
    "id": "chatcmpl-123",
    "object": "chat.completion",
    "created": 1677652288,
    "choices": [
        {
            "index": 0,
            "message": {
                "role": "assistant",
                "content": "\n\nHello there, how may I assist you today?"
            },
            "finish_reason": "stop"
        }
    ],
    "usage": {
        "prompt_tokens": 9,
        "completion_tokens": 12,
        "total_tokens": 21
    }
}

Modified at 2026-02-08 15:54:11

Create chat autocomplete (streaming)

Create a Thinking Chat