Create Message

Send a structured list of input messages with text and/or image content, and the model will generate the next message in the conversation.

POST /v1/messages

Create a Message

cURL

curl --request POST \
  --url https://www.anyfast.ai/v1/messages \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "claude-sonnet-5",
  "messages": [
    {
      "role": "user",
      "content": "Hello, Claude!"
    }
  ],
  "max_tokens": 1024,
  "system": "<string>",
  "metadata": {
    "user_id": "<string>"
  },
  "stop_sequences": [
    "<string>"
  ],
  "temperature": 1,
  "top_p": 0.5,
  "top_k": 1,
  "stream": false,
  "tools": [
    {
      "name": "<string>",
      "input_schema": {},
      "description": "<string>"
    }
  ],
  "tool_choice": {
    "name": "<string>"
  },
  "output_config": {},
  "thinking": {
    "budget_tokens": 1025
  }
}
'

import requests

url = "https://www.anyfast.ai/v1/messages"

payload = {
    "model": "claude-sonnet-5",
    "messages": [
        {
            "role": "user",
            "content": "Hello, Claude!"
        }
    ],
    "max_tokens": 1024,
    "system": "<string>",
    "metadata": { "user_id": "<string>" },
    "stop_sequences": ["<string>"],
    "temperature": 1,
    "top_p": 0.5,
    "top_k": 1,
    "stream": False,
    "tools": [
        {
            "name": "<string>",
            "input_schema": {},
            "description": "<string>"
        }
    ],
    "tool_choice": { "name": "<string>" },
    "output_config": {},
    "thinking": { "budget_tokens": 1025 }
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    model: 'claude-sonnet-5',
    messages: [{role: 'user', content: 'Hello, Claude!'}],
    max_tokens: 1024,
    system: '<string>',
    metadata: {user_id: '<string>'},
    stop_sequences: ['<string>'],
    temperature: 1,
    top_p: 0.5,
    top_k: 1,
    stream: false,
    tools: [{name: '<string>', input_schema: {}, description: '<string>'}],
    tool_choice: {name: '<string>'},
    output_config: {},
    thinking: {budget_tokens: 1025}
  })
};

fetch('https://www.anyfast.ai/v1/messages', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://www.anyfast.ai/v1/messages",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'model' => 'claude-sonnet-5',
    'messages' => [
        [
                'role' => 'user',
                'content' => 'Hello, Claude!'
        ]
    ],
    'max_tokens' => 1024,
    'system' => '<string>',
    'metadata' => [
        'user_id' => '<string>'
    ],
    'stop_sequences' => [
        '<string>'
    ],
    'temperature' => 1,
    'top_p' => 0.5,
    'top_k' => 1,
    'stream' => false,
    'tools' => [
        [
                'name' => '<string>',
                'input_schema' => [
                                
                ],
                'description' => '<string>'
        ]
    ],
    'tool_choice' => [
        'name' => '<string>'
    ],
    'output_config' => [
        
    ],
    'thinking' => [
        'budget_tokens' => 1025
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://www.anyfast.ai/v1/messages"

	payload := strings.NewReader("{\n  \"model\": \"claude-sonnet-5\",\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"Hello, Claude!\"\n    }\n  ],\n  \"max_tokens\": 1024,\n  \"system\": \"<string>\",\n  \"metadata\": {\n    \"user_id\": \"<string>\"\n  },\n  \"stop_sequences\": [\n    \"<string>\"\n  ],\n  \"temperature\": 1,\n  \"top_p\": 0.5,\n  \"top_k\": 1,\n  \"stream\": false,\n  \"tools\": [\n    {\n      \"name\": \"<string>\",\n      \"input_schema\": {},\n      \"description\": \"<string>\"\n    }\n  ],\n  \"tool_choice\": {\n    \"name\": \"<string>\"\n  },\n  \"output_config\": {},\n  \"thinking\": {\n    \"budget_tokens\": 1025\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://www.anyfast.ai/v1/messages")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"claude-sonnet-5\",\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"Hello, Claude!\"\n    }\n  ],\n  \"max_tokens\": 1024,\n  \"system\": \"<string>\",\n  \"metadata\": {\n    \"user_id\": \"<string>\"\n  },\n  \"stop_sequences\": [\n    \"<string>\"\n  ],\n  \"temperature\": 1,\n  \"top_p\": 0.5,\n  \"top_k\": 1,\n  \"stream\": false,\n  \"tools\": [\n    {\n      \"name\": \"<string>\",\n      \"input_schema\": {},\n      \"description\": \"<string>\"\n    }\n  ],\n  \"tool_choice\": {\n    \"name\": \"<string>\"\n  },\n  \"output_config\": {},\n  \"thinking\": {\n    \"budget_tokens\": 1025\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://www.anyfast.ai/v1/messages")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"claude-sonnet-5\",\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"Hello, Claude!\"\n    }\n  ],\n  \"max_tokens\": 1024,\n  \"system\": \"<string>\",\n  \"metadata\": {\n    \"user_id\": \"<string>\"\n  },\n  \"stop_sequences\": [\n    \"<string>\"\n  ],\n  \"temperature\": 1,\n  \"top_p\": 0.5,\n  \"top_k\": 1,\n  \"stream\": false,\n  \"tools\": [\n    {\n      \"name\": \"<string>\",\n      \"input_schema\": {},\n      \"description\": \"<string>\"\n    }\n  ],\n  \"tool_choice\": {\n    \"name\": \"<string>\"\n  },\n  \"output_config\": {},\n  \"thinking\": {\n    \"budget_tokens\": 1025\n  }\n}"

response = http.request(request)
puts response.read_body

200

{
  "id": "msg_01XFDUDYJgAACzvnptvVoYEL",
  "type": "message",
  "role": "assistant",
  "content": [
    {
      "type": "text",
      "text": "Hello! How can I help you today?"
    }
  ],
  "model": "claude-sonnet-5",
  "usage": {
    "input_tokens": 123,
    "output_tokens": 123,
    "cache_creation_input_tokens": 123,
    "cache_read_input_tokens": 123
  },
  "stop_sequence": "<string>"
}

{
  "type": "error",
  "error": {
    "type": "<string>",
    "message": "<string>"
  }
}

{
  "type": "error",
  "error": {
    "type": "<string>",
    "message": "<string>"
  }
}

{
  "type": "error",
  "error": {
    "type": "<string>",
    "message": "<string>"
  }
}

Authorizations

Authorization · string · header · required

Bearer authentication header of the form Bearer <token>, where <token> is your auth token.

Body

application/json

model · enum<string> · required

The model that will complete your prompt.

Available options: claude-sonnet-5, claude-sonnet-4-6, claude-sonnet-4-5-20250929, claude-sonnet-4-20250514, claude-opus-4-6, claude-opus-4-5-20251101, claude-opus-4-1-20250805, claude-opus-4-20250514, claude-haiku-4-5-20251001, claude-3-7-sonnet-20250219, claude-3-5-sonnet-20241022

Example:

"claude-sonnet-5"

messages · object[] · required

Input messages. Each message has a role and content.

Minimum array length: 1

Show child attributes

Example:

[
  {
    "role": "user",
    "content": "Hello, Claude!"
  }
]

max_tokens · integer · required

The maximum number of tokens to generate before stopping.

Required range: x >= 1

Example:

1024

system · string object[]

System prompt. Provides context and instructions to Claude.

metadata · object

An object describing metadata about the request.

Show child attributes

stop_sequences · string[]

Custom text sequences that will cause the model to stop generating.

temperature · number · default: 1

Amount of randomness injected into the response. Ranges from 0.0 to 1.0.

Required range: 0 <= x <= 1

Example:

1

top_p · number

Use nucleus sampling. Recommended to use either temperature or top_p, but not both.

Required range: 0 <= x <= 1

top_k · integer

Only sample from the top K options for each subsequent token.

Required range: x >= 0

stream · boolean · default: false

Whether to incrementally stream the response using server-sent events.

tools · object[]

Definitions of tools that the model may use.

Show child attributes

tool_choice · object

How the model should use the provided tools.

Show child attributes

output_config · object

Output controls for models that support adaptive thinking effort.

Show child attributes

thinking · object

Thinking configuration. For Claude Sonnet 5, use adaptive thinking or disable thinking; manual extended thinking with budget_tokens is not supported.

Show child attributes

Response

200

application/json

Message created successfully

id · string · required

Example:

"msg_01XFDUDYJgAACzvnptvVoYEL"

type · string · required

Example:

"message"

role · string · required

Example:

"assistant"

content · object[] · required

Show child attributes

Example:

[
  {
    "type": "text",
    "text": "Hello! How can I help you today?"
  }
]

model · string · required

Example:

"claude-sonnet-5"

stop_reason · enum<string> · required

Includes refusal when a request is declined.

Available options: end_turn, max_tokens, stop_sequence, tool_use, refusal, null

usage · object · required

Show child attributes

stop_sequence · string | null