Installation & Setup

Get jj running on your system and initialize your first repository.

Installing jj

macOS:

brew install jj

Linux (via cargo):

cargo install jj-cli

Download binary: Visit github.com/jj-vcs/jj/releases and download for your platform.

jj --version

You should see version output like jj 0.20.1.

jj can work alongside git in the same repository. This is called a "colocated" repository.

In an existing git repo:

cd my-project
jj git init --colocate

This creates .jj/ directory alongside .git/. Your git history is preserved and can still be used with git commands.

Start fresh (new repo):

mkdir new-project
cd new-project
jj git init

NOTE:

jj stores all its data in the .jj/ directory. You can always delete it to remove jj without affecting your git repository.

jj status

If successful, you'll see "No working copy changes" or similar status output.

With jj installed, let's explore the fundamental mental model difference between git and jj.