MCP Server

The tree-sitter-language-pack CLI includes an MCP server that exposes parsing, code intelligence extraction, language detection, and cache management as standard tools for AI agents. Use it to add code analysis to Claude, Cursor, VS Code, or any MCP-compatible application.

There are three ways to run it:

Bundled with the plugin — the coding-agent plugin registers the tree-sitter-language-pack MCP server for you and resolves the CLI automatically. Nothing to install by hand.
Direct MCP client config — point any MCP client at the published ts-pack CLI (see Installing the CLI below).
Hermes — for Hermes-based agents, install the runtime plugin with pip install tree-sitter-language-pack-hermes-plugin.

Installing the CLI

The ts-pack binary is published to every major registry. Install it with whichever fits your toolchain:

# Homebrew
brew install xberg-io/tap/ts-pack

# npm (Node.js)
npm install -g @xberg-io/ts-pack-cli

# uv / uvx (Python)
uvx --from ts-pack-cli ts-pack --version

# Cargo (Rust)
cargo install ts-pack-cli

Once ts-pack is on your PATH, any of the client configs below will work.

What is MCP?

The Model Context Protocol (MCP) is an open standard for connecting AI applications to tools and data. The tree-sitter-language-pack MCP server provides tools for parsing source code, analyzing structure and symbols, and managing language packs — all through a unified interface.

Starting the Server

Stdio Transport (Default)

For local AI tools — Claude Desktop, Cursor, VS Code — use stdio transport:

ts-pack mcp --transport stdio

Stdio is the default, so ts-pack mcp is equivalent. The server runs as a subprocess and communicates over stdin/stdout with JSON-RPC messages. No network configuration needed.

HTTP Transport

For remote agents or team environments where stdio doesn’t work:

ts-pack mcp --transport http --host 127.0.0.1 --port 8011

The server listens on http://127.0.0.1:8011 (default). Change --host to 0.0.0.0 for network-wide access (use with caution).

Custom Configuration

Point the server at a language-pack.toml config file:

ts-pack mcp --config /path/to/language-pack.toml

This sets default languages and download preferences for all tool calls.

Registering with AI Tools

Claude Desktop / Claude Code

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "tree-sitter-language-pack": {
      "command": "ts-pack",
      "args": ["mcp", "--transport", "stdio"]
    }
  }
}

Or use the CLI to register automatically:

claude mcp add tree-sitter-language-pack -- ts-pack mcp --transport stdio

Restart Claude. The tree-sitter-language-pack tools appear in the Tools panel.

Cursor

Edit .cursor/mcp.json in your project root (or global Cursor settings):

{
  "mcpServers": {
    "tree-sitter-language-pack": {
      "command": "ts-pack",
      "args": ["mcp", "--transport", "stdio"]
    }
  }
}

Reload Cursor. Tools are now available in the AI chat.

VS Code / GitHub Copilot

Edit .vscode/settings.json or your VS Code global settings:

{
  "mcpServers": [
    {
      "name": "tree-sitter-language-pack",
      "command": "ts-pack",
      "args": ["mcp", "--transport", "stdio"]
    }
  ]
}

Then reference tools in GitHub Copilot chat or use the Tools panel.

Generic MCP Client

For a client that spawns the server over stdio, point it at the ts-pack binary:

{
  "mcpServers": [
    {
      "name": "tree-sitter-language-pack",
      "command": "ts-pack",
      "args": ["mcp", "--transport", "stdio"]
    }
  ]
}

For an HTTP client, start the server yourself (ts-pack mcp --transport http --port 8011) and connect to its URL:

{
  "mcpServers": [
    {
      "name": "tree-sitter-language-pack",
      "url": "http://127.0.0.1:8011"
    }
  ]
}

Tools

The MCP server exposes 8 tools for parsing, analysis, and management:

parse

Render the syntax tree as S-expression or JSON.

Parameter	Type	Description
`source`	string	Source code to parse
`language`	string	Language name (e.g., `python`, `rust`)
`format`	string	Output format: `sexp` or `json` (default: `sexp`)

process

Extract code intelligence: structure, imports, exports, symbols, docstrings, comments, diagnostics, and optionally chunk for LLMs.

Parameter	Type	Description
`source`	string	Source code to analyze
`language`	string	Language name
`all`	boolean	Extract all intelligence fields (default: false)
`chunk_size`	integer	Split output into chunks for LLMs (optional)
`chunk_overlap`	integer	Overlap between chunks in tokens (optional)

detect_language

Identify language from file path or source code.

Parameter	Type	Description
`path`	string	File path (e.g., `main.rs`) — optional
`source`	string	Source code — optional, used if path unclear

list_languages

Enumerate available, downloaded, or manifest languages.

Parameter	Type	Description
`filter`	string	One of: `available` (default), `downloaded`, `manifest`
`query`	string	Filter by name or pattern (optional)

info

Get status of a specific language (available, downloaded, extensions, aliases).

Parameter	Type	Description
`name`	string	Language name (e.g., `python`)

download

Fetch language parsers for offline use.

Parameter	Type	Description
`languages`	array	List of language names — optional
`groups`	string	Download a group: `web`, `systems`, `data`, `all` — optional
`fresh`	boolean	Force fresh download (ignore cache)

cache_dir

Retrieve the local cache directory where parsers are stored.

Returns: path to the cache (e.g., ~/.ts-pack-cache)

clean_cache

Delete cached parsers.

Parameter	Type	Description
`all`	boolean	Delete all cached parsers (default: false)
`languages`	array	Delete parsers for specific languages — optional

Resources

The MCP server provides read-only resources for browsing the language catalog:

ts-pack://languages — list of all 371 available languages with extensions and aliases
ts-pack://languages/downloaded — list of user-downloaded languages
ts-pack://language/{name} — status of a specific language (template resource)

Prompt

The MCP server includes a built-in prompt template:

analyze-code

Analyzes source code by detecting its language, extracting code intelligence, and formatting results for readability. Use this when you want the agent to understand code structure without manual language specification.

Parameter	Type	Description
`source`	string	Source code to analyze
`focus`	string	What to extract: `all`, `structure`, `imports`, `exports`, `symbols` (default: `all`)

Using the Plugin Instead

For most users, installing the tree-sitter-language-pack plugin from the self-hosted xberg-io/tree-sitter-language-pack marketplace is simpler than manual MCP registration. The plugin ships a launcher script (scripts/mcp-launch.sh) that resolves the ts-pack CLI at runtime — via a cached binary, npx @xberg-io/ts-pack-cli, uvx --from ts-pack-cli ts-pack, Homebrew, or a prebuilt release download — and registers the tree-sitter-language-pack server for you.

See AI Coding Assistants for installation steps.

Next Steps

CLI Guide — full CLI command reference
Parsing Code — understanding syntax trees
Code Intelligence — extract structure and symbols
Installation — install ts-pack-cli