anthropic-mcp-connector

Anthropic MCP Connector Test Scripts

Test scripts demonstrating the Anthropic MCP Connector feature, which enables direct connection to remote MCP servers from the Messages API without a separate MCP client.

Overview

This repository contains both Python and TypeScript implementations that test the MCP Connector against a remote time server, demonstrating:

• Tool Discovery: Listing available MCP tools
• Tool Execution: Using MCP tools through the Messages API
• Multiple Tool Calls: Executing multiple tools in sequence
• New Content Types: Handling mcp_tool_use and mcp_tool_result blocks

Features Tested

• ✅ Direct API Integration: Connect to MCP servers without implementing an MCP client
• ✅ Tool Calling Support: Access MCP tools through the Messages API
• ✅ Multiple Servers: Support for connecting to multiple MCP servers
• ✅ Beta Feature: Uses the required anthropic-beta: mcp-client-2025-04-04 header

Files

Test Scripts

• test_mcp_connector.py - Python implementation using direct HTTP requests
• test-mcp-connector.ts - TypeScript implementation using the Anthropic SDK

Configuration

• mcp_servers.json - MCP server URL configuration
• .env - Environment variables (API key)
• package.json - Node.js dependencies for TypeScript version
• pyproject.toml - Python dependencies

Debug & Documentation

• debug_time_test.py - Debug script for isolating server issues
• README.md - This documentation

Prerequisites

1. Anthropic API Key: Get one from Anthropic Console
2. Python 3.9+ (for Python version)
3. Node.js 18+ (for TypeScript version)

Setup

1. Clone Repository

git clone <repository-url>
cd anthropic-mcp-connector

2. Environment Variables

Create a .env file:

ANTHROPIC_API_KEY=your_api_key_here

3. Python Setup

# Using uv (recommended)
uv pip install -r pyproject.toml

# Or using pip
pip install anthropic python-dotenv pytz requests

4. TypeScript Setup

npm install

Usage

Python Version

python test_mcp_connector.py

TypeScript Version

npm run test
# or
npm run dev  # with watch mode

Sample Output

Testing MCP Connector with server: https://mcp-server-http-time.mcpcentral.io
============================================================

🔍 Test 1: Discovering available tools
----------------------------------------
Response: Based on the available tools, I have access to a time server with the following functions:

## Time Server Tools
1. **current_time** - Get the current time
2. **relative_time** - Get relative time from now
3. **days_in_month** - Get days in a specific month
4. **get_timestamp** - Convert date/time to timestamp
5. **convert_time** - Convert time between timezones
6. **get_week_year** - Get week number and ISO week

⏰ Test 2: Getting current time
----------------------------------------
Text response: I'll get the current time for you using the time server.
🔧 MCP Tool Use:
  - Tool: current_time
  - Server: time-server
  - Input: {}
📊 MCP Tool Result:
  - Tool Use ID: mcptoolu_01E52bdMGmqrEqdfeQvXLxLU
  - Is Error: False
  - Content: [{'type': 'text', 'text': 'Current UTC time is 2025-05-31 04:23:31'}]

🌍 Test 3: Converting time between timezones
----------------------------------------
[Multiple tool calls demonstrating timezone conversion...]

✅ MCP Connector testing completed!

MCP Server Configuration

The test scripts connect to a time server that provides various time-related tools:

{
  "type": "url",
  "url": "https://mcp-server-http-time.mcpcentral.io",
  "name": "time-server"
}

Key Technical Implementation

Python Implementation

• Uses direct HTTP requests to the Messages API
• Includes proper error handling and status code checks
• Demonstrates manual parsing of MCP content blocks

TypeScript Implementation

• Uses the official Anthropic SDK with beta headers
• Includes comprehensive TypeScript interfaces for type safety
• Demonstrates modern async/await patterns

MCP Content Blocks

Both implementations handle the new MCP-specific content types:

interface MCPToolUse {
  type: 'mcp_tool_use';
  id: string;
  name: string;
  server_name: string;
  input: Record<string, any>;
}

interface MCPToolResult {
  type: 'mcp_tool_result';
  tool_use_id: string;
  is_error: boolean;
  content: Array<{ type: string; text?: string; [key: string]: any }>;
}

Testing Different Scenarios

You can modify the test scripts to test various scenarios:

1. Different MCP Servers: Update mcp_servers.json with your server URL
2. Authentication: Add authorization_token to the server configuration
3. Multiple Servers: Add multiple server objects to the mcp_servers array
4. Different Models: Change the model parameter to test with different Claude versions

Limitations

• Currently only tool calls are supported (not resources)
• Server must be publicly accessible via HTTP
• Local STDIO servers are not supported
• Not available on Amazon Bedrock or Google Vertex

Troubleshooting

Common Issues

1. "TypeError: Messages.create() got an unexpected keyword argument 'mcp_servers'"

   • Ensure you're using Anthropic SDK version 0.52.1 or later
   • Verify the beta header is included

2. Connection Errors

   • Check that the MCP server URL is accessible
   • Verify the server supports the required transport type

3. Authentication Errors

   • Ensure your API key is correctly set in .env
   • Check that you have access to the beta feature

Contributing

Feel free to submit issues or pull requests to improve these test scripts or add support for additional MCP server types.

License

MIT License - feel free to use and modify as needed.