velo/eclipse-mcp

Eclipse MCP Server Plugin

An Eclipse plugin that provides MCP (Model Context Protocol) server functionality, allowing external clients to interact with Eclipse IDE features programmatically.

Features

This plugin exposes the following Eclipse functionality through MCP tools:

Core Tools

• find_type: Locate Java types by name (similar to "Open Type" - Ctrl+Shift+T)
• find_resource: Locate resources by name (similar to "Open Resource" - Ctrl+Shift+R)
• run_tests: Run JUnit tests for individual files or methods
• get_problems: Read problems (errors/warnings) by project

Source Actions (Alt+Shift+S equivalent)

• source_actions: Execute Eclipse source actions
  • Generate getters/setters
  • Generate constructors
  • Generate toString()
  • Generate hashCode() and equals()

Refactoring Actions (Alt+Shift+T equivalent)

• refactor_actions: Execute Eclipse refactoring actions
  • Rename
  • Extract method
  • Extract variable
  • Inline
  • Move

Maven Integration

• maven_goal: Run Maven goals on projects
• maven_update_project: Update Maven project configuration

Architecture

The plugin consists of:

• MCP Server: JSON-RPC 2.0 compliant server running on configurable port (default: 8080)
• Tool System: Modular tool implementations for each Eclipse feature
• Resource System: Access to workspace projects and files
• Eclipse Integration: Deep integration with Eclipse JDT, Maven (M2E), and debug frameworks

Building

This project uses Eclipse Tycho for building. To build the plugin:

mvn clean install

To build for specific target platform:

mvn clean install -Dtycho.targetPlatform=/path/to/eclipse/installation

Installation

From Update Site

1. In Eclipse, go to Help → Install New Software
2. Add the update site URL (built in com.eclipse.mcp.updatesite/target/repository)
3. Select "MCP (Model Context Protocol)" category
4. Install and restart Eclipse

Manual Installation

1. Copy the built JAR from com.eclipse.mcp.server/target/ to Eclipse's dropins folder
2. Restart Eclipse

Configuration

Configure the MCP Server through Eclipse preferences:

• Go to Window → Preferences → MCP Server
• Enable/disable the server
• Configure server port (default: 8080)
• Set auto-start behavior

Usage

Once installed and configured, the MCP server will start automatically when Eclipse starts. External MCP clients can connect to the server on the configured port.

Example MCP Client Usage

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "find_type",
    "arguments": {
      "typeName": "String",
      "caseSensitive": false
    }
  }
}

Requirements

• Eclipse 2024-12 or later
• Java 21 or later
• Maven projects require M2E plugin
• Jackson OSGi bundles (typically included in Eclipse IDE packages)

Development

Project Structure

eclipse-mcp/
├── com.eclipse.mcp.server/          # Main plugin bundle
│   ├── src/main/java/
│   │   └── com/eclipse/mcp/server/
│   │       ├── handlers/            # MCP message handlers
│   │       ├── tools/              # Tool implementations
│   │       ├── protocol/           # MCP protocol classes
│   │       ├── startup/            # Eclipse startup integration
│   │       └── preferences/        # Preference pages
│   ├── META-INF/MANIFEST.MF        # OSGi bundle manifest
│   ├── plugin.xml                  # Eclipse plugin configuration
│   └── build.properties            # Build configuration
├── com.eclipse.mcp.feature/         # Eclipse feature definition
├── com.eclipse.mcp.updatesite/      # P2 update site
└── pom.xml                         # Parent Maven POM

Adding New Tools

1. Implement the Tool interface in com.eclipse.mcp.server.tools
2. Register the tool in ToolsCallHandler
3. Add tool definition in ToolsListHandler
4. Update documentation

Testing

The plugin can be tested by:

1. Running as Eclipse Application from the development environment
2. Using a MCP client to connect to port 8080
3. Sending MCP requests to test tool functionality

License

Eclipse Public License v2.0

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request