I discovered git worktree while asking Claude to work on several features in parallel. Agents editing the same checkout would step on each other's toes, so each one got its own worktree instead.

A worktree is an additional working directory attached to the same repository. All worktrees share the same .git history, objects and branches, but each has its own checked out branch, index and files on disk. No need to git stash or clone the repository a second time to work on another branch.

# Create ../myrepo-feature-a with a new branch feature-a
git worktree add -b feature-a ../myrepo-feature-a

# Check out an existing branch in another directory
git worktree add ../myrepo-fix fix-typo

# List the worktrees
git worktree list

# Remove a worktree once the branch is merged
git worktree remove ../myrepo-feature-a

A commit made in one worktree is immediately visible from the others, as they are the same repository. The only rule: a branch can be checked out in a single worktree at a time.