Core chain: brainstorming → writing-plans → [choice] → droids implement

When to use this skill:

• Working on existing git repository
• Need isolation from main branch
• Multiple features in parallel

Overview

Git worktrees create isolated workspaces sharing the same repository, allowing work on multiple branches simultaneously without switching.

Core principle: Systematic directory selection + safety verification = reliable isolation.

Announce at start: "I'm using the using-git-worktrees skill to set up an isolated workspace."

Directory Selection Process

Follow this priority order:

1. Check Existing Directories

# Use LS to check directories
LS(directory_path: ".worktrees") # Preferred (hidden)
LS(directory_path: "worktrees")  # Alternative

If found: Use that directory. If both exist, .worktrees wins.

2. Check AGENTS.md

Grep(pattern: "worktree.*director", path: "AGENTS.md")

If preference specified: Use it without asking.

3. Ask User

If no directory exists and no AGENTS.md preference:

No worktree directory found. Where should I create worktrees?

1. .worktrees/ (project-local, hidden)
2. ~/.factory/worktrees/<project-name>/ (global location)

Which would you prefer?

Safety Verification

For Project-Local Directories (.worktrees or worktrees)

MUST verify .gitignore before creating worktree:

Grep(pattern: "^\.worktrees/$", path: ".gitignore")
Grep(pattern: "^worktrees/$", path: ".gitignore")

If NOT in .gitignore:

Per Jesse's rule "Fix broken things immediately":

1. Add appropriate line to .gitignore
2. Commit the change using Execute
3. Proceed with worktree creation

Why critical: Prevents accidentally committing worktree contents to repository.

For Global Directory (~/.factory/worktrees)

No .gitignore verification needed - outside project entirely.

Creation Steps

1. Detect Project Name

Execute(command: "basename $(git rev-parse --show-toplevel)")

2. Create Worktree

# Use Execute to create worktree
Execute(command: "git worktree add path/to/worktree -b branch-name")

Bash logic for path determination (internal reference):

case $LOCATION in
  .worktrees|worktrees)
    path="$LOCATION/$BRANCH_NAME"
    ;;
  ~/.factory/worktrees/*)
    path="~/.factory/worktrees/$project/$BRANCH_NAME"
    ;;
esac

3. Run Project Setup

Auto-detect and run appropriate setup:

# Use Execute for setup commands
if [ -f package.json ]; then npm install; fi

# Rust
if [ -f Cargo.toml ]; then cargo build; fi

# Python
if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
if [ -f pyproject.toml ]; then poetry install; fi

# Go
if [ -f go.mod ]; then go mod download; fi

4. Verify Clean Baseline

Run tests to ensure worktree starts clean:

# Use Execute to run tests
npm test
cargo test
pytest
go test ./...

If tests fail: Report failures, ask whether to proceed or investigate.

If tests pass: Report ready.

5. Report Location

Worktree ready at <full-path>
Tests passing (<N> tests, 0 failures)
Ready to implement <feature-name>

Quick Reference

Common Mistakes

Skipping .gitignore verification

• Problem: Worktree contents get tracked, pollute git status
• Fix: Always Grep .gitignore before creating project-local worktree

Assuming directory location

• Problem: Creates inconsistency, violates project conventions
• Fix: Follow priority: existing > AGENTS.md > ask

Proceeding with failing tests

• Problem: Can't distinguish new bugs from pre-existing issues
• Fix: Report failures, get explicit permission to proceed

Hardcoding setup commands

• Problem: Breaks on projects using different tools
• Fix: Auto-detect from project files (package.json, etc.)

Example Workflow

You: I'm using the using-git-worktrees skill to set up an isolated workspace.

[Check .worktrees/ - exists]
[Grep .gitignore - contains .worktrees/]
[Execute: git worktree add .worktrees/auth -b feature/auth]
[Execute: npm install]
[Execute: npm test - 47 passing]

Worktree ready at /Users/galangryandana/myproject/.worktrees/auth
Tests passing (47 tests, 0 failures)
Ready to implement auth feature

TRANSITION: Loading writing-plans skill...
[SKILL(skill: "writing-plans")]

Red Flags

Never:

• Create worktree without .gitignore verification (project-local)
• Skip baseline test verification
• Proceed with failing tests without asking
• Assume directory location when ambiguous
• Skip AGENTS.md check

Always:

• Follow directory priority: existing > AGENTS.md > ask
• Verify .gitignore for project-local
• Auto-detect and run project setup
• Verify clean test baseline

Integration

Called by:

• brainstorming (Phase 4) - REQUIRED when design is approved and implementation follows
• Any skill needing isolated workspace

Pairs with:

• finishing-a-development-branch - REQUIRED for cleanup after work complete
• executing-plans or subagent-driven-development - Work happens in this worktree

⚠️ MANDATORY NEXT STEP - DO NOT SKIP

When worktree setup is complete:

1. Report worktree location and test status
2. IMMEDIATELY load: SKILL(skill: "writing-plans")
3. Create detailed implementation plan
4. ONLY THEN offer execution choice

You are FORBIDDEN from:

• Asking "what would you like to do next?" after worktree ready
• Offering execution choice before plan exists
• Starting to code without calling writing-plans
• Skipping plan "because design is clear enough"

Correct output after worktree ready:

Worktree ready at /path/to/worktree
Tests passing (N tests, 0 failures)

Now I'll create the implementation plan.

[IMMEDIATELY call SKILL(skill: "writing-plans")]

WRONG output (VIOLATION):

Worktree ready at /path/to/worktree
Tests passing (N tests, 0 failures)

What would you like to do next?  ← VIOLATION - must call writing-plans