Gl Fpc

MCP is a Free Pascal implementation of the Model Context Protocol It offers classes to implement a MCP server as well as a MCP client.

It also offers the start of a MCP tool server that will allow an AI agent to control Lazarus, and a MCP server that allows a LLM to execute queries on a database. Any database supported by FPC's SQLDB is supported.

License

This code is licensed with the usual FPC LGPL with linking exception license.

Repo layout

The docs directory contains a presentation of the framework given at the Pascal AI workshop organized by Blaise Pascal Magazine on 2025-07-12.

• mcp.lpg This is the project group containing all
• Src/Base contains the source code for all classes to create a MCP server
• Src/Client Contains the units with classes to create a MCP client.
• Src/IDE Contains the packages for Lazarus IDE integration
  • Lazarus IDE MCP tools
• Src/proxy Contains the MCP proxy (using the private socket protocol)
  • mcpproxy lifecycle and reconnect behavior
• demo Contains a demo project. Simulates a weather service
• dbconnector Contains a MCP server allowing to execute SQL statements on a database/

Installation

• Open the Src/Base/mcpbase.lpk package in the lazarus IDE.
• Open the Src/Client/mcpclient.lpk package in the lazarus IDE.
• Open the Src/Base/mcpdesign.lpk package in the lazarus IDE and install it. This will install 4 components on the component palette on tab MCP.
• if you wish to allow an LLM to control the lazarus IDE, compile and install Src/IDE/mcplazcontrol.lpk to actually allow the LLM to control the IDE, you must use the mcpproxy.

Compiling the programs:

After you have opened the mcpbase.lpk package; you can compile all three sample programs:

• demo/client/mcpclient.lpi (a generic MCP client)
• demo/client/mockserver.pp (a small mock MCP server, to be used for testing)
• demo/weather.lpi (small demo)
• demo/search/mcpsearch.lpi (MCP server to execute web searches using Tavily)
• src/proxy/mcpproxy.lpi (StdIO to Socket transport proxy)
• dbconnector/mcpdbconnector.lpi