VSC-MCP

VSC-MCP

This project provides tools that expose Language Server Protocol (LSP) functionality as MCP (Model Context Protocol) tools. It enables AI agents to programmatically analyze and edit TypeScript/JavaScript code through standardized MCP tool calls.

Features

• Works in single-file mode or project mode (tsconfig.json detection).
• Language-agnostic code manipulation through LSP APIs.
• Fully compatible with Model Context Protocol (MCP) SDK.

Installation

Prerequisites

• Bun (for package management and building)
• Node.js (for running the server)

Setup

1. Clone the repository
2. Install dependencies:

   bun install
   

Configuration in Claude (macOS)

To use with Claude Desktop, add the server configuration to the Claude Desktop config file:

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

Add the following configurations to the mcp_servers section of the config file:

{
  "mcpServers": {
    "repomix": {
      "command": "npx",
      "args": [
        "-y",
        "repomix",
        "--mcp"
      ]
    },
    "vsc-mcp": {
      "command": "bun",
      "args": [
        "/path/to/your/vsc-mcp/src/index.ts"
      ],
      "env": {
        "LOG_DIR": "/path/to/your/vsc-mcp/logs",
        "ALLOWED_DIRECTORIES": "/path/to/your/vsc-mcp"
      }
    }
  }
}

We need the repomix mcp server dependency.

Replace /path/to/your/vsc-mcp with the actual path to your vsc-mcp cloned directory.

Security Features

Path Restriction

The VSC-MCP tools include a security feature to restrict file operations to specific directories:

• ALLOWED_DIRECTORIES: An environment variable that specifies a comma-separated list of directories where file operations are permitted.

  Example:

  ALLOWED_DIRECTORIES=/home/user/projects,/tmp/workspace
  

• If this environment variable is not set, operations default to the current working directory only.

• All file operations (read, write, edit) will check if the target path is within the allowed directories.

• Attempting to access files outside allowed directories will result in an "Access denied" error.

This feature helps prevent unauthorized access to sensitive files and directories on the system.

How It Works

• Launches the typescript-language-server in --stdio mode.
• Sends LSP initialize and didOpen notifications.
• Finds symbols using workspace/symbol and textDocument/documentSymbol requests.
• Falls back to textDocument/implementation for additional symbol discovery.
• Applies edits directly to files using applyWorkspaceEdit utility.
• Returns the result of the operation to the caller.

Available Tools

Currently, the following tools are available:

• editSymbol: Edits a symbol (function, class, method, etc.) by name and type in a given file using LSP.

  • Supports various symbol types: function, method, class, interface, variable, constant, property, field
  • Uses LSP's workspace/symbol and textDocument/documentSymbol requests to find symbols
  • Applies edits directly to files

• readSymbol: Reads a symbol (function, class, method, etc.) by name and type in a given file using LSP.

  • Supports the same symbol types as editSymbol
  • Uses LSP to locate the symbol and extract its content
  • Returns the symbol content along with its location information

• readFile: Reads the content of a file.

  • Returns the file content with appropriate MIME type based on file extension
  • Handles various file formats including code, text, and configuration files
  • Provides detailed error messages for common issues (file not found, directory access, etc.)

• writeFile: Creates a new file or overwrites an existing file with the provided content.

  • Creates parent directories if they don't exist
  • Supports any file type
  • Returns information about the file operation (created/overwritten, file size)

• searchReplaceFile: Searches for content in a file and replaces it with new content.

  • Ignores whitespace differences when searching (spaces, tabs, newlines)
  • Supports flexible matching of content patterns
  • Returns the number of replacements made