jj

Jujutsu (jj) Version Control

This project uses jj (Jujutsu) for version control. Always use jj commands — never git commit, git add, or git branch.

Before making any code changes

Run:

jj log --no-graph -r @ --template 'change_id.short() ++ " | " ++ if(description, description, "(empty)")'

This gives you the current working-copy revision and its description.

Decision rule

Compare the current revision description with the task you are about to implement:

• Same semantic scope (e.g. both about fixing the same bug, same feature): continue working in the current revision — no action needed.
• Different semantic scope (different feature, unrelated fix, new task): create a new revision before touching any files:

jj new -m "<short description of what you're about to do>"

This ensures each revision stays focused on a single logical change.

Core workflow

Check status

jj status

Describe current revision

jj describe -m "<message>"

Use after completing a logical unit of work. Follow the project's commit message convention if present.

Create new revision from current

jj new -m "<message>"

View history

jj log

Undo last operation

jj undo

Hard rules

• Check jj log -r @ before editing any file
• If the revision description is empty (empty) — describe it before or after your changes
• Never use git commit or git add — jj tracks changes automatically, no staging needed
• One revision = one logical change; do not mix unrelated modifications in a single revision
• If unsure whether the scope matches — create a new revision; it's cheap to squash later with jj squash