Messages API (Anthropic-compatible)

Anthropic-compatible This endpoint mirrors Anthropic’s Messages API. It is used by tools like Claude Code and the official Anthropic SDK.

Request Parameters

model

string

required

Target model ID (for example: claude-sonnet-4.5).

max_tokens

integer

required

Maximum number of tokens to generate (minimum: 1).

messages

array

required

Conversation messages (minimum: 1; maximum: 100000).Each item is a MessageParam object:

role (required): "user" | "assistant"
content (required): string or an array of typed blocks (discriminator: type)

Show MessageParam shape

{ "role": "user|assistant", "content": "string|array" }

Show content blocks (messages[].content[])

Show text

{ "type": "text", "text": "..." }

text (required): string

Show image

{ "type": "image", "source": { "type": "url", "url": "https://..." } }

Show image.source (oneOf)

URL image:

{ "type": "url", "url": "https://..." }

Base64 image:
```
{ "type": "base64", "media_type": "image/png", "data": "<base64>" }
```
- media_type (required): image/jpeg | image/png | image/gif | image/webp
- data (required): raw base64

Show document

{ "type": "document", "title": "optional", "source": { "type": "url", "url": "https://..." } }

title (optional): string | null

Show document.source (oneOf)

URL PDF:

{ "type": "url", "url": "https://..." }

Base64 PDF:
```
{ "type": "base64", "data": "<base64>" }
```
(media_type is implicitly application/pdf)
Plain text:
```
{ "type": "text", "data": "..." }
```
Inline content:
```
{ "type": "content", "content": "..." }
```
(content can also be an array of objects)

Show search_result

{ "type": "search_result", "title": "optional", "source": "optional", "content": [{ "type": "text", "text": "..." }] }

Show thinking

{ "type": "thinking", "thinking": "...", "signature": "optional" }

Show redacted_thinking

{ "type": "redacted_thinking", "data": "..." }

Show tool_use

{ "type": "tool_use", "id": "toolu_...", "name": "my_tool", "input": { "x": 1 } }

Show tool_result

{ "type": "tool_result", "tool_use_id": "toolu_...", "content": "..." }

content (optional): string | array (defaults to "")

system

string | array

Optional system prompt. Can be:

a string, or
an array of text blocks: { "type": "text", "text": "..." }

stream

boolean

default:"false"

Whether to stream the response.

temperature

number

Sampling temperature (0..2). Higher values make output more random.

top_p

number

Nucleus sampling probability (0..1). Alternative to temperature.

stop_sequences

string[]

Stop sequences. Generation stops when any stop sequence is encountered.

tools

array

Tool definitions (Anthropic Messages API format).

Show ToolParam shape

{ "name": "my_tool", "description": "optional", "input_schema": { "type": "object", "properties": {} } }

name (required): string
description (optional): string | null
input_schema (required): object (JSON Schema for tool inputs)

tool_choice

object

Tool choice strategy (Anthropic format).

Show Supported shapes (discriminator: type)

Auto tool use:

{ "type": "auto", "disable_parallel_tool_use": false }

Any tool (force tool usage):

{ "type": "any", "disable_parallel_tool_use": false }

Specific tool by name:

{ "type": "tool", "name": "my_tool", "disable_parallel_tool_use": false }

No tools:
```
{ "type": "none" }
```

thinking

object

Thinking configuration (Anthropic format).

Show Supported shapes (discriminator: type)

Disable thinking:
```
{ "type": "disabled" }
```
Enable thinking:
```
{ "type": "enabled", "budget_tokens": 0 }
```
- budget_tokens (optional): integer (minimum 0)

Usage examples

from anthropic import Anthropic

client = Anthropic(
    base_url="https://api.naga.ac",
    api_key="YOUR_API_KEY",
)

message = client.messages.create(
    max_tokens=1024,
    messages=[
        {
            "role": "user",
            "content": "Hello, Claude!",
        }
    ],
    model="claude-sonnet-4.5",
)

print(message.content)

Response

Returns an Anthropic-compatible Messages API response object.

API Guides

API Reference

Messages API (Anthropic-compatible)

Request Parameters

Usage examples

Response

API Guides

API Reference

​Request Parameters

​Usage examples

​Response

Request Parameters

Usage examples

Response