Claude message

POST

/v1/messages

Claude

Creates a message using Claude models via native Anthropic Messages API format. This endpoint follows the official Anthropic API specification.

How To Use

Simply specify the model name in your request payload. All other parameters remain the same across different models.

Authentication

Use x-api-key header instead of Bearer token.

Supported Models

claude-opus-4-8

claude-opus-4-7

claude-opus-4-7-thinking

claude-opus-4-6

claude-opus-4-6-thinking

claude-haiku-4-5-20251001

claude-haiku-4-5-20251001-thinking

claude-opus-4-5-20251101

claude-opus-4-5-20251101-thinking

claude-sonnet-4-5-20250929

claude-sonnet-4-5-20250929-thinking

Request

Authorization

API Key

Add parameter in header

x-api-key

Example:

x-api-key: ********************

Header Params

Body Params application/jsonRequired

Examples

Basic messageWith system promptMulti-turn conversation

{
    "model": "claude-sonnet-4-5-20250929",
    "max_tokens": 1024,
    "messages": [
        {
            "role": "user",
            "content": "Hello, Claude"
        }
    ]
}

Request Code Samples

Shell

JavaScript

Java

Swift

PHP

Python

HTTP

Objective-C

Ruby

OCaml

Dart

cURL

Basic messageWith system promptMulti-turn conversation

curl --location '/v1/messages' \
--header 'anthropic-version;' \
--header 'x-api-key: <api-key>' \
--header 'Content-Type: application/json' \
--data '{
    "model": "claude-sonnet-4-5-20250929",
    "max_tokens": 1024,
    "messages": [
        {
            "role": "user",
            "content": "Hello, Claude"
        }
    ]
}'

Responses

🟢200

application/json

Successful response

Bodyapplication/json

Example

{
    "id": "msg_01XFDUDYJgAACzvnptvVoYEL",
    "type": "message",
    "role": "assistant",
    "content": [
        {
            "type": "text",
            "text": "Hello! How can I assist you today?"
        }
    ],
    "model": "claude-sonnet-4-5-20250929",
    "stop_reason": "end_turn",
    "usage": {
        "input_tokens": 12,
        "output_tokens": 8
    }
}

🟠400

🟠401

🟠429

🔴500

Modified at 2026-07-29 01:22:52

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