pi-jj — jj (jujutsu) extension for pi

Automatically intercepts git commands when working in a jj project and redirects to jj equivalents.

What it does

When a .jj directory is detected in your project:

• System prompt injection — appends a jj guide to every agent turn, so the agent always knows it's in a jj project
• Git command interception — intercepts bash tool calls that use git and either:
  • Auto-transforms safe read-only commands (git status → jj status, git log → jj log, etc.)
  • Blocks dangerous commands (git commit, git add, git stash, etc.) with a message explaining the jj equivalent
• Status indicator — shows 🦀 jj in the footer when active

Auto-transformed commands

These git commands are silently rewritten to jj equivalents:

git	jj
git status	jj status
git log	jj log
git diff	jj diff
git show	jj show
git blame	jj annotate
git push	jj git push
git pull	jj git pull
git fetch	jj git fetch
git branch -a	jj bookmark list --all

Blocked commands with guidance

These git commands are blocked with a message suggesting the jj equivalent:

git commit, git add, git stash, git checkout, git merge, git rebase, git reset, git cherry-pick, git revert, git switch, and more.

Install

pi install https://github.com/cole/pi-jj

Manual install

cp -r extensions/pi-jj ~/.pi/agent/extensions/

Then /reload in pi.

Commands

Command	Description
/jj	Show current jj detection status
/jj on	Re-enable jj interception
/jj off	Disable jj interception for this session
/jj status	Show whether jj project is detected
/jj help	Show help

How it works

1. On session_start, checks for .jj directory in the project root
2. On before_agent_start, injects a jj reference into the system prompt
3. On tool_call for bash commands, detects git invocations and either transforms or blocks them
4. Uses /jj command for manual control

Why?

AI agents default to git commands. In a jj project, running git commit or git stash can cause confusion because jj manages the working copy differently. This extension ensures the agent always uses the right tool for the job.