MCP Language Server

🚀 MCP Language Server

A Model Context Protocol (MCP) server that runs a language server and provides tools to communicate with it.

🚀 Quick Start

This README provides an overview of the MCP Language Server, including its motivation, current state, available tools, feedback mechanisms, and future plans.

✨ Features

Motivation

Claude Desktop with the filesystem server feels like magic when working on small projects. But as you add a few files and imports, that magic starts to fade. With this project, I hope to bring that experience to large projects as well.

Language servers excel at tasks where LLMs often struggle, such as precisely understanding types, relationships, and providing accurate symbol references. This project aims to bring these tools to LLMs. LSP also seems like an obvious inspiration for MCP, so why not combine them?

Status

⚠️ Pre-beta quality ⚠️

I've tested this server with the following language servers:

• gopls (Go)
• pyright (Python)
• typescript-language-server (TypeScript)
• rust-analyzer (Rust)

But it should be compatible with many other language servers.

Tools

• read_definition: Retrieve the full source code definition of any symbol (function, type, constant, etc.) in the codebase.
• find_references: Locate all uses and references of a symbol in the codebase.
• get_diagnostics: Provide diagnostic information, including warnings and errors, for a specific file.
• get_codelens: Retrieve code lens hints for additional context and actions.
• execute_codelens: Execute a code lens action.
• apply_text_edit: Allow multiple text edits to a file.
• hover: Display documentation, type hints, or other hover information at a location.
• rename_symbol: Rename a symbol throughout the project.

Feedback

Include the following to get detailed LSP and application logs:

env: {
  "LOG_LEVEL": "DEBUG",
}

Setting LOG_LEVEL to DEBUG enables detailed logging for all components. Add LOG_COMPONENT_LEVELS with wire:DEBUG to show the raw LSP JSON messages. Please provide as much detail as possible when submitting an issue.

Future Plans

The following features are on my radar:

• [x] Read definition
• [x] Find references
• [x] Apply edits
• [x] Get diagnostics
• [x] Code lens
• [x] Hover information
• [x] Rename symbol
• [ ] Code actions
• [ ] Better handling of context and cancellation
• [ ] Add LSP server configuration options and presets for common languages
• [ ] Create tools at a higher level of abstraction that combine diagnostics, code lens, hover, and code actions to read definitions or references.