Language Server MCP server

The MCP Server is a TypeScript implementation of the Model Context Protocol designed to enhance code editing experiences. It provides language features such as hover information, code completion, and diagnostics for code, with current testing focused primarily on TypeScript support.

Installation

Prerequisites

Before installing the MCP server, ensure you have Node.js installed on your system.

Setup Process

1. Install the MCP server package:

npm install language-server-mcp

2. Configure Claude Desktop to use the MCP server by adding the server configuration to the Claude Desktop config file:

MacOS:

~/Library/Application Support/Claude/claude_desktop_config.json

Windows:

%APPDATA%/Claude/claude_desktop_config.json

3. Add the following configuration to the JSON file:

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

Make sure to replace /path/to/language-server-mcp with the actual path to the installed server on your system.

Usage

Available Tools

The MCP server provides three main tools for code assistance:

Get Hover Information

Retrieves hover information for a specific position in a document.

Required parameters:

• languageId: The language identifier (e.g., "typescript")
• filePath: Path to the file
• content: The document content
• line: Line number (zero-based)
• character: Character position (zero-based)

Get Completions

Fetches completion suggestions for a specific position in a document.

Required parameters:

• languageId: The language identifier (e.g., "typescript")
• filePath: Path to the file
• content: The document content
• line: Line number (zero-based)
• character: Character position (zero-based)

Get Diagnostics

Retrieves diagnostic information (errors, warnings) for a document.

Required parameters:

• languageId: The language identifier (e.g., "typescript")
• filePath: Path to the file
• content: The document content

Debugging

Since MCP servers communicate over stdio, you can use the MCP Inspector for debugging:

npm run inspector

The Inspector will provide a URL to access debugging tools in your browser, helping you track communications between the client and server.

Supported Languages

While the server has been primarily tested with TypeScript, it should theoretically support Python as well. Support for additional languages may be added in future versions.

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "language-server-mcp" '{"command":"/path/to/language-server-mcp/build/index.js"}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

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

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

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

3. Restart Claude Desktop for the changes to take effect