New Feature skill

New Feature

Each editing task gets its own worktree and branch, created from the latest origin/main unless the user specifies a different base. Read-only work can use the existing checkout. Never build on main or reuse another task's work.

Check existing isolation first

Inspect git worktree list, git status --short, the current branch, and the session's task assignment. If the environment already created a worktree for this task, keep its path and branch and skip steps 3 and 4. In step 5, use the actual assigned path. Do not infer isolation from the editor name or a branch prefix alone. Otherwise follow all steps.

Steps

1. Sync: git fetch origin.

2. Scope check: run gh pr list and skim the open PRs' changed files (gh pr diff <n> --name-only). For shared files, read the overlapping diffs. Independent edits may proceed in your own worktree. Ask for direction only when the changes conflict in behavior, require another task's unfinished work, or ownership is unclear. Check shared checkouts for uncommitted work without changing it. On another hosting platform, use its equivalent PR/MR tools; if unavailable, report the scope-check limitation and still isolate.

3. Name the task: lowercase-with-hyphens plus a short unique suffix, e.g. user-auth-0816a. If git worktree add fails because the name exists, pick a different name — never force or reuse.

4. Create the worktree from the repo root:

   git worktree add <worktrees-dir>/<task-name> \
     -b <branch-prefix>/<task-name> origin/main
   

   Use a directory outside the checkout, or a gitignored directory inside it, so worktrees cannot be committed by accident. Use a consistent branch prefix (e.g. agent/). Follow the repo's conventions if it defines them.

5. Enter and verify:

   cd <worktrees-dir>/<task-name>
   git branch --show-current   # must print your new branch, not main
   

   Confirm the required runtime version. Install dependencies inside the worktree when needed for the task's checks. Documentation-only work does not require installing an unrelated application toolchain.

Remember

• Worktrees do not isolate dev-server ports or shared databases. Tracked dependency lockfiles are separate in each worktree. Confirm a port answers your process (lsof -i :<port>) before trusting what it serves, and resolve lockfile conflicts by regenerating, never by hand-merging.

• Keep the worktree until the PR is merged or closed. Cleanup after merge:

  git worktree remove <worktrees-dir>/<task-name>
  git branch -D <branch-prefix>/<task-name>
  

  -D is expected: after a squash- or rebase-merge, -d refuses even though the work is merged.