# Connect Anthropic Messages API to aicharged.io

> Anthropic Messages API MCP connector (beta): mcp_servers plus an mcp_toolset — Claude calls aicharged.io straight from the API.

## At a glance

| Kind | Sign-in | Platforms | Status | Verified |
|---|---|---|---|---|
| SDKs & frameworks | API key (Bearer) | macOS, Linux, Windows | works today | 2026-10-22 |

- MCP: `https://aicharged.io/api/v1/mcp`
- Docs: https://platform.claude.com/docs/en/agents-and-tools/mcp-connector

## Recipe

Hosted MCP tool — the API calls aicharged.io for you:

```python
import os
import anthropic

client = anthropic.Anthropic()
response = client.beta.messages.create(
    model="claude-opus-5-5",
    max_tokens=16000,
    betas=["mcp-client-2025-11-20"],
    messages=[{"role": "user", "content": "List my recent aicharged.io runs"}],
    mcp_servers=[{
        "type": "url",
        "url": "https://aicharged.io/api/v1/mcp",
        "name": "aicharged",
        "authorization_token": os.environ["AICHARGED_API_KEY"],
    }],
    tools=[{"type": "mcp_toolset", "mcp_server_name": "aicharged"}],
)
print(response.content)
```

Beta feature: keep the mcp-client-2025-11-20 beta flag. The API sends authorization_token to aicharged.io as the Bearer token.

The same request with curl:

```sh
curl https://api.anthropic.com/v1/messages \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: mcp-client-2025-11-20" \
  -H "content-type: application/json" \
  -d '{
    "model": "claude-opus-5-5",
    "max_tokens": 16000,
    "messages": [{"role": "user", "content": "List my recent aicharged.io runs"}],
    "mcp_servers": [{"type": "url", "url": "https://aicharged.io/api/v1/mcp", "name": "aicharged", "authorization_token": "<API_KEY>"}],
    "tools": [{"type": "mcp_toolset", "mcp_server_name": "aicharged"}]
  }'
```

[Client documentation](https://platform.claude.com/docs/en/agents-and-tools/mcp-connector)

## Authentication

- Send `Authorization: Bearer <API_KEY>` with every request. Create a key at https://aicharged.io/admin/account/api-keys.
- OAuth 2.1 (PKCE S256) is available for clients that cannot send a static key (ChatGPT).
- Without a key the endpoint answers 401 with a WWW-Authenticate header that points to https://aicharged.io/.well-known/oauth-protected-resource.

All 51 clients: https://aicharged.io/connect.md

HTML version: https://aicharged.io/connect/anthropic-messages-api