Delphi MCP Server

A Model Context Protocol (MCP) server implementation in Delphi, designed to integrate with Claude Code, Codex, and other MCP-compatible clients for AI-powered Delphi development workflows.

Table of Contents

• Features
• Requirements
• Installation
• Transport Modes
• Protocol Versions and Dual-Era Behaviour
• Using as a Library
• Integration with Claude Code
• Integration with Codex
• Testing with MCP Inspector
• Available Example Tools
• Available Example Prompts
• Available Example Resources
• Configuration
  • Authentication
  • Network and Security
• License
• Contributing
• About GDK Software
• Support
• Commercial Support

Features

• Dual-era MCP: Serves MCP 2026-07-28 (per-request _meta, server/discover) and the initialize-based revisions 2025-06-18 and 2025-11-25 on the same endpoint and the same stdio process; see Protocol versions
• Dual Transport Support: HTTP (Streamable HTTP with SSE) and STDIO (stdin/stdout)
• Dual Response Mode: Supports both JSON-RPC and Server-Sent Events in the same server
• Tool System: Extensible tool system with RTTI-based discovery and execution
• Resource Management: Modular resource system supporting various content types
• Security: Origin and Host validation against DNS rebinding on every request, loopback binding by default, CORS headers for browser clients, request size and nesting limits, opt-in bearer authentication with OAuth 2.1 resource-server discovery
• Multi round-trip requests, streaming and subscriptions: InputRequiredResult with signed requestState, progress and log notifications on the response stream, subscriptions/listen for change notifications
• Native HTTP stack: Indy HTTP server with keep-alive, no external runtime
• Optional Parameters: Support for optional tool parameters using custom attributes
• Cross-Platform: Supports Windows (Win32/Win64) and Linux (x64)

Requirements

• Delphi 11 Alexandria or later. The source uses no language feature beyond inline variables (10.3) and no RTL unit newer than Delphi 11; development happens on Delphi 12 Athens, which is what the default project files target.
• Windows (Win32/Win64) or Linux (x64)
• No external dependencies (all required libraries included)

Building with Delphi 11 Alexandria

build.bat and build-tests.bat compile the .dpr directly, so only DELPHI_PATH needs to point at your installation:

set DELPHI_PATH=C:\Program Files (x86)\Embarcadero\Studio\22.0
build.bat

For the IDE and for the Linux64 build, open src/MCPServer.D11.dproj (tests: tests/MCPServerTests.D11.dproj) instead of the Athens project files. They carry the same units and settings, write their output to a separate D11 subdirectory, and exist because Alexandria will not load a ProjectVersion 20.3 project file.

Installation

For Standalone Usage

1. Clone the repository:

git clone https://github.com/GDKsoftware/delphi-mcp-server.git
cd delphi-mcp-server

2. Build the project:

Windows Build

build.bat

Or specify configuration and platform:

build.bat Debug Win32
build.bat Release Win64