jj MCP Server

A Model Context Protocol (MCP) server for Jujutsu (jj) version control. Enables AI assistants to work with jj repositories using the correct workflow.

Tools

Tool	Description
status	Show working directory state
log	View commit history and graph
diff	Show changes in a revision
describe	Set commit message for @ (does NOT create new commit)
new	Create new empty commit (optionally from specific parent)
bookmark_create	Create a named bookmark at a revision
push	Push a bookmark to remote
sync	Fetch from all remotes
rebase	Move commits in the graph

jj Workflow (for AI assistants)

jj is NOT git. Key differences:

• @ is your current working commit - changes go directly into it
• There is no staging area
• describe sets a message but doesn't move anything
• new creates a fresh empty commit; previous @ becomes @-

Correct workflow:

sync                              # fetch latest
new(parents="main")               # start from main
[make changes]                    # changes are in @
describe(message="what I did")    # label the work
new                               # ready for next change
[repeat as needed]
bookmark_create(name="feature")   # name the work
push(bookmark="feature")          # ship it

Installation

cargo install --path .

Configuration

Add to ~/.claude/mcp.json:

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

Prerequisites

• Jujutsu (jj) installed and in PATH
• Rust toolchain (for building)

License

MIT