What is a sandbox copy?
A copy of a folder from your computer, placed on an isolated machine, where an agent can work freely. The original stays untouched until you bring the changes back.
Updated October 1, 2026
Short answer. A sandbox copy lets an agent work on your real project without running on your real computer. In Macaron, the copy lives on a Computer, and Apply to Mac writes the agent's changes back to the original folder only if they apply cleanly.
Why copy at all
Cloning from GitHub only gets what you've pushed. A sandbox copy takes the folder as it is on your machine, including uncommitted work, so the agent starts from exactly where you are, without being given access to the rest of your computer.
How it works in Macaron
- 01You pick a folder on your Mac and a Computer to copy it to.
- 02Macaron copies the folder, including uncommitted files, and skips ignored files and dependency and build folders. The original isn't changed.
- 03The agent works on the copy: edits, installs, runs your checks, serves a preview.
- 04You review the changes, then choose Apply to Mac.
- 05If the changes apply cleanly to the original folder, they're written back. If they don't, for example because you edited the same lines in the meantime, nothing is written.
Sandbox copy vs worktree vs clone
- Sandbox copy
- Where the agent runsAn isolated machine
- Includes uncommitted workYes
- How changes come backApplied to the original folder, only if clean
- Git worktree
- Where the agent runsYour own machine, as you
- Includes uncommitted workNo, a new branch from a base
- How changes come backMerge or pull request
- Fresh clone
- Where the agent runsAnywhere
- Includes uncommitted workNo, only what's pushed
- How changes come backPush and pull request
- Mounted folder
- Where the agent runsA container with your folder inside
- Includes uncommitted workYes
- How changes come backImmediately: the agent edits your real files
| Where the agent runs | Includes uncommitted work | How changes come back | |
|---|---|---|---|
| Sandbox copy | An isolated machine | Yes | Applied to the original folder, only if clean |
| Git worktree | Your own machine, as you | No, a new branch from a base | Merge or pull request |
| Fresh clone | Anywhere | No, only what's pushed | Push and pull request |
| Mounted folder | A container with your folder inside | Yes | Immediately: the agent edits your real files |
A mounted folder looks like a sandbox, but the agent writes straight into your files. A sandbox copy keeps a step between the agent's work and your folder.
When a copy is the wrong choice
- The task is small and you're watching every step: run the agent in the folder directly.
- The project is mostly dependencies or generated files you need inside the sandbox: they're skipped, so they'll be installed or built again.
- Teammates need the result: a branch and pull request is the better route back.
Questions
Does a sandbox copy include my .env file?+
Ignored files are skipped, and .env files are usually in .gitignore. Pass the credentials a run needs through connectors instead.
What happens if I edit the original while the agent works?+
Nothing breaks. When you choose Apply to Mac, the changes are written only if they still apply cleanly to your current files.
Is the copy deleted afterwards?+
It stays on the Computer, whose files persist until you remove them, so you can come back to it.
Is this the same as a git stash or branch?+
No. Those stay in your repository on your machine. A sandbox copy is a separate folder on a separate machine.