Code Forge — Worktree

Create an isolated git worktree for feature development with automated project setup and safety verification.

When to Use

• Starting feature work that should not affect the main workspace
• Before running code-forge:impl to isolate implementation changes
• When you need a clean baseline for testing or experimentation

Iron Law

NEVER create a project-local worktree without verifying it is git-ignored. Worktree contents tracked by git will cause repository corruption.

Workflow

Detect Directory → Verify Safety → Create Worktree → Project Setup → Baseline Tests → Report

Step 1: Detect Worktree Directory

Check in order:

1. Existing .worktrees/ or worktrees/ directory in project root — use if found
2. Project CLAUDE.md for worktree preference — use without asking
3. Ask user:
   • Project-local .worktrees/ (Recommended) — keeps worktrees near the code
   • Global ~/.config/code-forge/worktrees/ — outside project, no .gitignore needed

Step 2: Verify Safety (Project-Local Only)

CRITICAL: If using a project-local directory:

git check-ignore -q <worktree-dir>

• Ignored: Proceed
• NOT ignored: Add to .gitignore immediately, then commit:

  echo "<worktree-dir>/" >> .gitignore
  git add .gitignore && git commit -m "chore: add worktree directory to .gitignore"
  

Global directory: skip this step.

Step 3: Create Worktree

# Detect project name
PROJECT_NAME=$(basename "$(git rev-parse --show-toplevel)")

# Create worktree with new branch
git worktree add <worktree-dir>/<feature-name> -b <feature-name>

Branch naming: use the feature name provided by the user, prefixed with feat/ if not already prefixed.

Step 4: Project Setup

Auto-detect and run setup in the worktree directory:

If multiple markers exist, run the most specific one. If none match, skip setup.

Step 5: Baseline Tests

Run the project's test command to establish a clean baseline:

# Auto-detect test command from package.json, Makefile, etc.
# Run tests and report results

• All pass: Report green baseline, proceed
• Some fail: Warn user — "Baseline has N failing tests. These are pre-existing, not caused by your changes."
• No test command found: Skip, inform user

Step 6: Report

Worktree created:
  Branch:    feat/<feature-name>
  Location:  <worktree-dir>/<feature-name>
  Setup:     npm install (completed)
  Baseline:  42/42 tests passing

Next steps (code-forge workflow):
  /code-forge:impl <feature-name>    Execute implementation tasks
  /code-forge:finish                  When done, merge/PR/cleanup

Next steps (ad-hoc development):
  /code-forge:tdd                    Enforce TDD discipline
  /code-forge:finish                  When done, merge/PR/cleanup

Example

$ /code-forge:worktree user-auth

Worktree created:
  Branch:    feat/user-auth
  Location:  .worktrees/user-auth
  Setup:     npm ci (completed)
  Baseline:  42/42 tests passing

Next steps:
  /code-forge:impl user-auth    Execute implementation tasks
  /code-forge:finish             When done, merge/PR/cleanup

Cleanup

To remove a stale worktree manually: git worktree remove <path>. List all worktrees with git worktree list. The /code-forge:finish skill handles cleanup automatically.

Common Mistakes

• Creating project-local worktree without checking .gitignore
• Skipping baseline tests — pre-existing failures mask new regressions
• Hardcoding setup commands instead of auto-detecting
• Proceeding when baseline tests fail without user acknowledgment