Your First Commits

Making commits in jj is different from git—there's no staging area to manage.

The jj Commit Workflow

In jj, commits are created in two steps:

jj describe - Name/edit the current @ commit
jj new - Finalize @ and create a new empty commit

echo "hello" > file.txt

jj describe -m "Add file"

jj new

Command comparison: git commands on the left, jj commands on the right
git	jj
echo "hello" > file.txt	echo "hello" > file.txt
git add file.txt	jj describe -m "Add file"
git commit -m "Add file"	jj new

Understanding `jj describe`

jj describe edits the current @ commit's message. It doesn't create a new commit.

# Edit the @ commit message
jj describe -m "Initial implementation"

# Or open editor
jj describe

# See the updated message
jj show @

Understanding `jj new`

jj new finalizes the current @ commit and creates a new @ commit on top of it.

# Current @ commit has changes
jj status

# Finalize it, create new @
jj new

# Now @ is empty (no changes yet)
jj status

Step-by-Step Example

Let's create three commits:

# 1. Start with a clean slate
jj new
# Working copy now at @

# 2. Create first file and commit
echo "console.log('hello')" > app.js
jj describe -m "Add hello world"
jj new

# 3. Create second file and commit
echo "export const x = 42" > config.js
jj describe -m "Add config"
jj new

# 4. Modify existing file
echo "console.log('hello world')" >> app.js
jj describe -m "Update greeting"
jj new

Editing the Last Commit

Need to change the last commit message?

jj describe -m "New message"

Command comparison: git commands on the left, jj commands on the right
git	jj
git commit --amend -m "New message"	jj describe -m "New message"

If you've already run jj new and want to edit the previous commit:

# Edit the parent of @
jj edit @-

# Now @ is that commit
jj describe -m "Corrected message"

# Create new @ to finalize
jj new

Viewing Your Commits

# Show current @ commit
jj show @

# Show commit history
jj log

# Show parent commit
jj show @-

What About `git add`?

In jj, there's no jj add command. All file changes are automatically part of the @ commit.

vim a.js

vim b.js

vim c.js

jj status

Command comparison: git commands on the left, jj commands on the right
git	jj
vim a.js	vim a.js
vim b.js	vim b.js
vim c.js	vim c.js
git add a.js	jj status
git add b.js
git commit -m "Partial commit"

NOTE:

jj's philosophy is that it's better to create separate commits for different changes, then use jj squash or jj rebase to reorganize. This avoids the complexity of selective staging.

Common Patterns

Quick commit cycle:

# Make changes
vim file.js

# Commit
jj describe -m "Fix bug"
jj new

Forget to describe before jj new:

# Made changes, ran jj new too soon
jj new
# Oops, commit message is empty

# Fix it
jj edit @-
jj describe -m "The message I meant"
jj new

Multiple edits before finalizing:

# Make changes
vim app.js

# Describe
jj describe -m "Add feature"

# Make more changes
vim config.js

# Update description
jj describe -m "Add feature and config"

# Finally commit
jj new

Try It Yourself

Key Takeaways

jj describe edits the current @ commit message
jj new finalizes @ and creates a new empty commit
No staging area—all changes are auto-tracked
Edit previous commits with jj edit @-

Next Steps

Now that you can create commits, let's explore how jj handles branching differently from git.

Practice Exercises

0/4 completed

1Check repository status
2View commit history
3Name the working copy commit
4Create a new commit