jj Version Control Skill

Prerequisites

Always try jj commands directly without any prerequisite checks.

If a jj command fails (e.g., "There is no jj repo in..."), ask the user how they would like to proceed (e.g., use git instead, initialize jj, or something else).

Common Operations

Check Status

bash

jj status

Shows the current working copy status and any conflicts.

View History

bash

jj log

Shows commit history with change IDs. Use -r to filter revisions.

View Diff

bash

# Diff of working copy
jj diff

# Diff of specific revision
jj diff -r @-

Create a Commit

In jj, you work differently from git. The working copy is always a commit:

bash

# Describe the current working copy change
jj describe -m "commit message"

# Start a new empty change on top
jj new

Or combine both:

bash

jj commit -m "commit message"

Amend Current Change

bash

# Add more changes to current commit
jj squash

Squash Into Parent

bash

jj squash

Split a Commit

bash

jj split

Interactive tool to split the current change into multiple commits.

Rebase

bash

# Rebase current change onto main
jj rebase -d main

# Rebase a branch
jj rebase -s <change-id> -d <destination>

Bookmarks (Branches)

bash

# List bookmarks
jj bookmark list

# Create/move bookmark to current change
jj bookmark set <name>

# Delete bookmark
jj bookmark delete <name>

Undo

bash

jj undo

Undo the last jj operation.

Push to Remote

bash

# Push all bookmarks
jj git push

# Push specific bookmark
jj git push -b <bookmark-name>

Fetch from Remote

bash

jj git fetch

Commit Message Guidelines

•Use conventional commit format when appropriate (feat:, fix:, docs:, etc.)
•Keep the first line under 72 characters
•Add blank line before detailed description if needed
•
Add Co-Authored-By trailer for AI-assisted commits:
code
```
Co-Authored-By: Claude <noreply@anthropic.com>
```

Key Differences from Git

Git	jj
`git add` + `git commit`	`jj commit` or `jj describe` + `jj new`
`git stash`	Not needed - just `jj new`
`git branch`	`jj bookmark`
`git checkout`	`jj edit` or `jj new -r`
`git rebase -i`	`jj rebase` + `jj squash` / `jj split`
`git log`	`jj log`
`git diff`	`jj diff`