language-server-mcp MCP Server

language-server-mcp MCP Server

A Model Context Protocol (MCP) server providing language support for code editing.

This is a TypeScript-based MCP server designed to enhance code editing experiences by providing features such as hover information, code completion, and diagnostics. It demonstrates core MCP concepts by providing:

• Language-specific tools for code analysis and manipulation
• Integration with the Model Context Protocol for seamless communication

Features

Language Support

• Provides hover information for symbols in code
• Offers code completion suggestions
• Reports diagnostic information (errors, warnings)
• Only tested with typescript, theoretically should support Python. Would love to add additional language servers or be more agnostic if possible.

MCP Integration

• Implements the MCP protocol for communication with clients
• Exposes language features as MCP tools

Tools

• get_hover: Get hover information for a position in a document
  • Takes languageId, filePath, content, line, and character as required parameters
• get_completions: Get completion suggestions for a position in a document
  • Takes languageId, filePath, content, line, and character as required parameters
• get_diagnostics: Get diagnostic information for a document
  • Takes languageId, filePath, and content as required parameters

Development

Install dependencies:

npm install

Build the server:

npm run build

For development with auto-rebuild:

npm run watch

Installation

To use with Claude Desktop, add the server config:

On MacOS: ~/Library/Application Support/Claude/claude_desktop_config.json On Windows: %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "language-server-mcp": {
      "command": "/path/to/language-server-mcp/build/index.js"
    }
  }
}

Debugging

Since MCP servers communicate over stdio, debugging can be challenging. We recommend using the MCP Inspector, which is available as a package script:

npm run inspector

The Inspector will provide a URL to access debugging tools in your browser.