LSP MCP Server

An MCP (Model Context Protocol) server that provides unified access to Language Server Protocol features for multiple programming languages.

Features

Multi-language support: Rust, TypeScript/JavaScript, Python, Go, C/C++
Full IDE features exposed as MCP tools:
- lsp_hover - Type info and documentation
- lsp_goto_definition - Navigate to symbol definitions
- lsp_find_references - Find all usages of a symbol
- lsp_completion - Code completion suggestions
- lsp_document_symbols - List symbols in a file
- lsp_workspace_symbols - Search symbols across workspace
- lsp_rename_symbol - Rename symbols across files
- lsp_diagnostics - Get errors and warnings

Prerequisites

Language servers must be installed and available in PATH:

Language	Server	Install
Rust	rust-analyzer	`rustup component add rust-analyzer`
TypeScript/JS	typescript-language-server	`npm i -g typescript-language-server typescript`
Python	pyright	`npm i -g pyright` or `pip install pyright`
Go	gopls	`go install golang.org/x/tools/gopls@latest`
C/C++	clangd	Install via system package manager

Installation

cargo install --path .

Usage

As MCP Server

Add to your MCP client configuration:

{
  "mcpServers": {
    "lsp": {
      "command": "lsp-mcp"
    }
  }
}

Tool Examples

1. Activate a workspace first:

{
  "tool": "lsp_activate_workspace",
  "arguments": {
    "workspace_path": "C:/path/to/project"
  }
}

2. Get hover info:

{
  "tool": "lsp_hover",
  "arguments": {
    "file_path": "C:/path/to/project/src/main.rs",
    "line": 10,
    "character": 5
  }
}

3. Find definition:

{
  "tool": "lsp_goto_definition",
  "arguments": {
    "file_path": "C:/path/to/project/src/main.rs",
    "line": 15,
    "character": 12
  }
}

4. Find references:

{
  "tool": "lsp_find_references",
  "arguments": {
    "file_path": "C:/path/to/project/src/main.rs",
    "line": 5,
    "character": 7,
    "include_declaration": true
  }
}

Development

# Build

cargo build


# Run in development

cargo run


# Run tests

cargo test


# Build release

cargo build --release

Architecture

lsp-mcp/
├── src/
│   ├── main.rs           # Entry point
│   ├── lib.rs            # Public API
│   ├── error.rs          # Error types
│   ├── server/           # MCP server
│   │   └── mcp_server.rs # Tool registration
│   ├── lsp/              # LSP client layer
│   │   ├── client.rs     # LSP client wrapper
│   │   ├── manager.rs    # Multi-server manager
│   │   ├── config.rs     # Server configurations
│   │   └── transport.rs  # Stdio transport
│   └── tools/            # MCP tools
│       ├── workspace.rs  # Workspace management
│       ├── hover.rs      # Hover info
│       ├── definition.rs # Go to definition
│       └── ...           # Other tools

License

MIT

lsp-mcp 0.1.0