Claude Integration

LazyJJ integrates with Claude CLI for AI-assisted development workflows.

Prerequisites

Install Claude CLI:

npm install -g @anthropic-ai/claude-code

Optional but recommended:

• tmux - For workspace management

Commands

Command	Shortcut	Purpose
claude-start	clstart	Create JJ workspace + tmux session
claude-stop	clstop	Stop and clean up workspace
claude-resolve	clresolve	Resolve conflicts using Claude
claude-review	clreview	Review a PR using Claude
claude-checkpoint	-	Save checkpoint with message

Workspace Management

Claude workspaces let you have Claude work on your code in an isolated JJ workspace:

# Start a Claude workspace
jj claude-start my-feature

# Output:
# Started tmux session: my-feature
# Attach with: tmux attach -t my-feature

This creates:

1. A JJ workspace at .jj-workspaces/my-feature
2. A tmux session running Claude

When done:

# Stop and clean up
jj claude-stop my-feature

Conflict Resolution

When you have merge conflicts, Claude can help:

# After a rebase with conflicts
jj claude-resolve

This runs Claude on each conflicted file to help resolve it.

PR Review

Have Claude review a pull request:

# Review current PR
jj claude-review

# Review specific PR
jj claude-review 123

Checkpointing

Create checkpoints while working:

# Save your progress with a message
jj claude-checkpoint "got auth working"

This describes the current commit and creates a new one.

Why Claude + JJ is Powerful

The combination of Claude and JJ creates unique advantages:

1. Safe Experimentation

JJ’s operation log means Claude can try things without fear. If Claude makes a mistake:

jj undo  # Reverse Claude's last action
jj op log  # See what Claude did
jj op restore <id>  # Jump back if needed

2. First-Class Conflicts

JJ’s conflict model means Claude can attempt merges or rebases without blocking you. If conflicts arise, they’re just marked—you can keep working.

3. Natural Language → Stack Operations

Claude understands stack-based workflows. You can ask:

• “Split this change into 3 stacked commits”
• “Rebase my stack onto main and resolve conflicts”
• “Edit the second commit in my stack to fix the bug”

Claude can manipulate your stack directly using JJ’s powerful commands.

Workflow Example

A typical AI-assisted development session:

# Start fresh from trunk
jj stack-start

# Start a Claude workspace for your feature
jj claude-start auth-feature

# Attach to Claude session
tmux attach -t auth-feature

# ... Claude helps you implement the feature ...

# Checkpoint your work periodically
jj claude-checkpoint "basic auth flow done"

# When done, stop the workspace
jj claude-stop auth-feature

# Review and clean up your commits
jj stack-view
jj squash  # if needed

# Create PR
jj pr-stack-create

Tips

Multiple Claude Sessions

You can have multiple Claude workspaces:

jj claude-start feature-a
jj claude-start feature-b

# List workspaces
jj workspace list

# Attach to specific session
tmux attach -t feature-a

Without tmux

If you don’t have tmux, claude-start still creates the workspace:

.jj-workspaces/my-feature

jj claude-start my-feature
# tmux not available - start Claude manually in that directory

cd .jj-workspaces/my-feature
claude

Cleaning Up Old Workspaces

# List all workspaces
jj workspace list

# Forget a workspace
jj workspace forget workspace-name

# Remove the directory
rm -rf .jj-workspaces/workspace-name