Jujutsu MCP Server

A comprehensive Model Context Protocol (MCP) server that provides access to Jujutsu VCS operations. This server enables AI assistants to interact with Jujutsu repositories through a standardized interface.

Installation

Prerequisites

• Jujutsu VCS must be installed and available in your PATH
• Node.js 18+

Installation for Popular MCP Clients

Claude Desktop

1. Install the server globally:

   npm install -g jujutsu-mcp-server

2. Add this to your Claude Desktop configuration:

   macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%/Claude/claude_desktop_config.json

   {
     "mcpServers": {
       "jujutsu": {
         "command": "jujutsu-mcp-server"
       }
     }
   }

Cursor

1. Install the server using npx (no global installation needed):

   npx jujutsu-mcp-server --version

2. In Cursor, go to Settings → Features → Model Context Protocol

3. Add the server configuration:

   {
     "jujutsu": {
       "command": "npx",
       "args": ["jujutsu-mcp-server"]
     }
   }

Cline (VS Code Extension)

1. Install the server using npx (no global installation needed):

   npx jujutsu-mcp-server --version

2. In VS Code, open Cline settings (Cmd/Ctrl + Shift + P → "Cline: Open Settings")

3. Add to the MCP servers configuration:

   {
     "mcpServers": {
       "jujutsu": {
         "command": "npx",
         "args": ["jujutsu-mcp-server"]
       }
     }
   }

Continue (VS Code Extension)

1. Install globally or use npx:

   npm install -g jujutsu-mcp-server
   # OR use npx (no installation needed)
   npx jujutsu-mcp-server --version

2. Add to your ~/.continue/config.json:

   {
     "mcpServers": {
       "jujutsu": {
         "command": "jujutsu-mcp-server"
       }
     }
   }

   Or if using npx:

   {
     "mcpServers": {
       "jujutsu": {
         "command": "npx",
         "args": ["jujutsu-mcp-server"]
       }
     }
   }

Other MCP Clients

This server follows the standard MCP protocol and should work with any compatible client. You can use either:

• Global installation: npm install -g jujutsu-mcp-server then use jujutsu-mcp-server as command
• Via npx: Use npx as command with ["jujutsu-mcp-server"] as args

Features

• Complete Jujutsu Command Coverage: Access to all major jj commands including bookmarks, commits, rebasing, and more
• Repository Information as Resources: Get real-time repository status, configuration, and history
• Safe Command Execution: Proper error handling and command validation
• Automatic Repository Detection: Finds Jujutsu repositories by looking for .jj directories
• Modern MCP Implementation: Built with the latest MCP SDK patterns and best practices

Available Tools

The server provides comprehensive access to Jujutsu commands through MCP tools:

Repository Information

• jj_status - Show repository status including working copy changes and conflicts
• jj_log - Show revision history with optional filtering and formatting
• jj_show - Show commit description and changes in a specific revision
• jj_diff - Compare file contents between revisions
• jj_root - Show workspace root directory
• jj_version - Display Jujutsu version information

Bookmark Operations

• jj_bookmark_list - List bookmarks and their targets
• jj_bookmark_create - Create new bookmarks
• jj_bookmark_set - Update existing bookmarks
• jj_bookmark_delete - Delete bookmarks (marked as dangerous)
• jj_bookmark_move - Move bookmarks between revisions

Working Copy Operations

• jj_new - Create new, empty changes
• jj_edit - Set working-copy revision
• jj_describe - Update change descriptions and metadata
• jj_commit - Update description and create new change on top

Change Operations

• jj_squash - Move changes from one revision to another
• jj_split - Split a revision into two
• jj_duplicate - Create copies of existing changes

Rebase Operations

• jj_rebase - Move revisions to different parents
• jj_abandon - Abandon revisions (marked as dangerous)

Git Integration

• jj_git_fetch - Fetch from Git remotes
• jj_git_push - Push to Git remotes
• jj_git_clone - Clone Git repositories

File Operations

• jj_file_list - List files in revisions
• jj_file_show - Show file contents

Conflict Resolution

• jj_resolve - Resolve conflicts with merge tools

Operation Log

• jj_operation_log - Show operation history
• jj_operation_undo - Undo operations (marked as dangerous)

Workspace Management

• jj_workspace_list - List workspaces
• jj_workspace_add - Add new workspaces

Configuration

• jj_config_list - List configuration variables
• jj_config_get - Get configuration values
• jj_config_set - Set configuration values

Available Resources

The server exposes repository information as MCP resources accessible via jj:// URIs:

• jj://repository/status - Current repository status
• jj://repository/config - Repository configuration
• jj://repository/log - Recent commit history
• jj://repository/bookmarks - List of bookmarks
• jj://repository/remotes - Git remotes
• jj://repository/operation-log - Recent operations
• jj://repository/workspaces - Available workspaces

Usage Examples

Basic Repository Operations

Ask your AI assistant to:

• "Show me the current status of the repository"
• "Display the recent commit history"
• "List all bookmarks in the repository"

Working with Changes

• "Create a new change with message 'Fix bug in parser'"
• "Show the diff between the current change and its parent"
• "Squash the current change into its parent"

Bookmark Management

• "Create a bookmark called 'feature-branch' on the current change"
• "List all remote bookmarks"
• "Move the 'main' bookmark to revision abc123"

Git Integration

• "Fetch changes from the origin remote"
• "Push the current bookmark to origin"
• "Clone the repository from https://github.com/example/repo.git"

Safety Features

Commands marked as "dangerous" in the tool definitions (like jj_abandon, jj_bookmark_delete, jj_operation_undo) will be clearly identified. The AI assistant should warn users before executing these operations.

Error Handling

The server includes comprehensive error handling:

• Validates that Jujutsu is installed before starting
• Automatically detects Jujutsu repository roots
• Provides clear error messages for failed operations
• Handles command timeouts (60 seconds default)

Development

If you want to contribute or modify the server:

1. Clone the repository
2. Install dependencies:

   pnpm install

3. Build the server:

   pnpm run build

4. Test locally:

   pnpm test

For development with auto-rebuild:

pnpm run watch

Debugging

Since MCP servers communicate over stdio, debugging can be challenging. We recommend using the MCP Inspector:

pnpm run inspector

The Inspector will provide a URL to access debugging tools in your browser.

Adding New Commands

To add support for additional Jujutsu commands:

1. Add the command definition to the getJJCommands() method
2. Add argument parsing logic in buildCommandArgs()
3. Test the command with the MCP Inspector
4. Update this README with the new functionality

Troubleshooting

"jj is not installed or not in PATH"

Make sure Jujutsu VCS is installed and available in your system PATH. You can test this by running jj --version in your terminal.

"Not in a Jujutsu repository"

The server automatically detects Jujutsu repositories by looking for .jj directories. Make sure you're working within a Jujutsu repository or create one with jj git clone or jj init.

Server not responding

Check that the server configuration in your MCP client points to the correct command (jujutsu-mcp-server for global install or npx with ["jujutsu-mcp-server"] args).

Contributing

Contributions are welcome! Please ensure:

• New commands include proper input validation
• Error handling follows existing patterns
• Documentation is updated for new features
• Commands that can modify repository state are clearly marked

License

This project is open source under the MIT License. See the LICENSE file for details.