Anthropic API: Messages

ZenMux supports the Anthropic API. See the API call examples below for usage. For detailed request parameters and response schemas, refer to the Anthropic documentation.

Supported Features

All Anthropic API features are supported except for the following:

1. The header parameter anthropic-version only supports "2023-06-01".
2. The header parameter anthropic-beta does not support "code-execution-2025-08-25", i.e., the code_execution tool is unavailable.

API Call Examples

When using cURL directly, you must specify anthropic-version: 2023-06-01 (this is the only supported version).

Python

import anthropic

## 1. Initialize the Anthropic client
client = anthropic.Anthropic(
    # Replace with the API key from your ZenMux console
    api_key="<YOUR ZENMUX_API_KEY>", 
    # 3. Point the base URL to the ZenMux endpoint
    base_url="https://zenmux.ai/api"
)
message = client.messages.create(
    model="anthropic/claude-3.5-sonnet",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Hello, Claude"}
    ]
)
print(message.content)

TypeScript

import Anthropic from '@anthropic-ai/sdk';

// 1. Initialize the Anthropic client
const anthropic = new Anthropic({
  // 2. Replace with the API key from your ZenMux console
  apiKey: '<YOUR ZENMUX_API_KEY>', 
  // 3. Point the base URL to the ZenMux endpoint
  baseURL: "https://zenmux.ai/api", 
});

async function main () {
    const msg = await anthropic.messages.create({
        model: "anthropic/claude-3.5-sonnet",
        max_tokens: 1024,
        messages: [{ role: "user", content: "Hello, Claude" }],
    });
    console.log(msg);
}

main();

cURL

curl https://zenmux.ai/api/v1/messages \
     --header "x-api-key: $ZENMUX_API_KEY" \
     --header "anthropic-version: 2023-06-01" \
     --header "content-type: application/json" \
     --data \
'{
    "model": "anthropic/claude-3.5-sonnet",
    "max_tokens": 1024,
    "messages": [
        {"role": "user", "content": "Hello, world"}
    ]
}'

Claude Code Usage

See Claude Code Integration