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2 min readThe Agent Swarm Team

Why every agent gets its own sandbox

Isolation isn't a nice-to-have for parallel agents — it's the thing that makes them safe. Here's how we think about it.

If you've ever run two agents against the same working directory, you know the failure mode: one edits a file, the other reads a half-written version, and both end up confused.

Isolation makes parallelism safe

In Agent Swarm, every agent runs in its own cloud sandbox, branched from main. That single decision unlocks a lot:

  • A planner reads the codebase without a coder mutating it underneath.
  • A coder runs the full test suite without slowing anyone else down.
  • Heavy work — builds, Playwright, large installs — never touches your laptop.
main
 ├─ sandbox A  planner
 ├─ sandbox B  coder
 └─ sandbox C  tester

Stale state becomes a notification

The hard part of parallel work is staying in sync. When one agent merges to main, the others get a signal: main moved, here's the diff since your branch point. Each agent decides whether to reconcile or ignore it.

That's much cheaper than re-reading the whole repo, and it removes the endless "go look at the code again" loop that plagues single-context agents.

The feedback loop stays tight

Isolation usually means things feel remote. We fixed that with a streamed desktop, a live terminal, and branch-aware diffs — so even though the work happens in the cloud, it feels like it's right in front of you.

Read more in the Isolated sandboxes docs.