How Do You Keep Parallel AI Agents From Stepping on Each Other?

Give every agent its own isolated workspace. The proven mechanism is one git worktree per agent — a separate working copy of the codebase on its own branch — so parallel agents physically cannot overwrite each other's files. Work merges back through commits a human reviews, and an agent that goes off the rails gets replaced without contaminating anyone else's lane.

This is the question that separates people who've run one agent from people who've run five. One agent can't conflict with anyone. The moment you run several against the same project, you've inherited the oldest problem in team software: concurrent edits to shared state. Orchestration lives or dies on how it answers.

What actually goes wrong when agents share a workspace?

Run two capable agents in the same directory and the failure modes arrive fast, in escalating order of pain:

• Silent overwrites. Agent A writes a file; Agent B rewrites it thirty seconds later. No error, no conflict marker — A's work is just gone, and nobody tells you.
• Cross-contamination. Agent B reads A's half-finished changes as if they were the real codebase and builds on sand.
• Unreviewable output. When both finish, the diff is a braid of two intentions. You can't approve one task's work without untangling the other's.
• One crash poisons everything. An agent that goes sideways leaves debris in the one workspace every other agent depends on.

None of these are the model's fault. They're an architecture fault: shared mutable state with no isolation.

Why are git worktrees the right isolation cell?

Git worktrees are git's native answer to "work on several branches at once": each worktree is a full working copy in its own folder, on its own branch, sharing one repository history. That maps one-to-one onto the parallel-agent problem, which is why Orca builds on them directly — orca work dispatches each task to an agent in its own isolated worktree, where you watch the commits land and review the diffs.

The properties you get for free:

1. Physical isolation. Two agents "editing the same file" are editing two copies. Live collision is impossible, not just unlikely.
2. Attribution. Every branch is one agent's work on one task. The diff you review is exactly what that agent did — it spot-checks cleanly, one lane at a time.
3. Honest conflicts. If two tasks really did touch the same lines, git surfaces it as a merge conflict at integration time — visible, resolvable once, instead of silent lost work.
4. Disposable failure. A bad run is a branch you never merge. Delete it; the codebase never knew.

Isolation isn't enough — who's watching the lanes?

Worktrees stop agents from destroying each other's work. They don't stop an agent from quietly doing the wrong work in its own lane. That's the orchestrator's job on top of the isolation layer, and it's why Orca pairs worktrees with three habits:

• One screen over everything. 8+ sessions visible in one terminal UI — you can watch and steer any agent without alt-tabbing through windows.
• Spot-checks on the work, not the word. Autopilot checks the actual diffs and commits, not the agent's summary of them, and surfaces each commit as it ships.
• Harpoon + recycle. An agent stuck or off track gets harpooned; Orca reuses the slot instantly with a fresh agent that picks up clean. Because the failure was confined to a worktree, the crew never stalls and nothing leaks.

A self-healing pod: nothing stalls the others.

What about conflicts you create at the planning step?

The cheapest conflict is the one you never dispatch. If you hand two agents overlapping tasks — "refactor the auth module" and "add logging to the auth module" — worktrees will keep them from corrupting each other, but you've still bought yourself a merge to untangle. Split the backlog into genuinely independent lanes first; the planning discipline is covered in how to run multiple AI agents in parallel, and the overlapping-task trap is mistake #2 in orchestration mistakes founders make.

Does the same principle apply beyond the agents?

Yes — and it's a tell for judging orchestration tools. Orca applies the isolation principle to itself: it installs into its own folder plus a single command on your PATH, writes only to its own directory at runtime, and never edits your shell config, your Claude Code settings, or any dotfiles. The one Claude config file it touches, it reads only. A tool built on "never step on what isn't yours" tends to extend that respect to your machine.

FAQ

What is a git worktree, in plain terms?

A git worktree is an additional working copy of your repository, checked out on its own branch in its own folder, sharing the same underlying history. It's git's built-in way to work on several branches simultaneously — which makes it a natural isolation cell for parallel agents.

Can two Orca agents edit the same file at the same time?

Each edits its own copy of that file, in its own worktree, on its own branch — so nothing is overwritten live. If both changes touch the same lines, that surfaces later as an ordinary git merge conflict you resolve once, with full visibility, instead of silent lost work.

What happens when an agent goes off the rails mid-task?

In Orca you harpoon it. The stuck agent is removed, the slot is reused instantly with a fresh agent that picks up clean, and because all its work was confined to its own worktree, nothing it did can leak into anyone else's lane. The pod keeps a full crew working.

Will Orca itself mess with my existing setup or settings?

No. Orca installs into its own folder plus a single command on your PATH, and at runtime only writes to its own directory. It never edits your shell config, your Claude Code settings, or any dotfiles — isolation is the design principle for the tool itself, not just the agents.