Implementing a client

Overview

• Shifting focus from server to client implementation in mcp_client. py
• This project uniquely implements both client and server (typically you'd use one or the other)
• Client allows access to server functionality from the rest of the codebase

MCPClient Class Purpose

• Wraps a client_session (the actual connection to the MCP server)
• Client session is part of the MCP Python SDK
• Manages resource cleanup through connect(), async_enter(), and async_exit() functions
• Wrapping the session in a class simplifies resource management

Client Responsibilities

• Exposes server functionality to the codebase
• Gets list of tools to send to Claude
• Executes tools requested by Claude
• Other code in the core/ directory calls client functions like list_tools(), call_tool(), list_prompts(), get_prompt()

Key Functions to Implement

list_tools()

• Returns await self. session. list_tools()
• Returns result. tools to get all available tools from the server
• Provides tool definitions (name, description, input schema) to Claude

call_tool()

• Returns await self. session. call_tool(tool_name, tool_input)
• Takes tool name and input parameters from Claude
• Executes the tool on the server and returns results

Testing

• Testing harness at bottom of file allows running mcp_client. py directly
• Can verify tools are accessible and callable
• Once implemented, other code can use these functions to enable Claude to inspect and edit documents

Takeaways

• MCPClient wraps a client_session to manage the connection to the MCP server and simplify resource cleanup
• The client exposes server functionality to the codebase through functions like list_tools(), call_tool(), list_prompts(), and get_prompt()
• list_tools() returns available tool definitions (name, description, input schema) to send to Claude
• call_tool() executes tools requested by Claude by calling the server with the tool name and input parameters
• A testing harness at the bottom of the file allows direct verification that tools are accessible and callable