Turn changes and Undo - Mains

After a turn changes files, its change card shows the edited files and diff counts. It gives you a patch for that turn, even if later work changes the workspace.

Review a turn

Open Review on the card to inspect its patch. This is different from Changes, which shows everything currently uncommitted in the workspace. A turn’s patch can include new files and binary changes. Stopping a run leaves its edits on disk; it does not apply Undo.

Undo

Choose Undo when you want to reverse that turn’s patch. Mains checks whether it can safely reverse the recorded changes against the current files. If later work makes the patch incompatible, Undo can be unavailable or fail. Inspect the current diff before trying another way to revert it.

Shared edits

Several chats can use the same workspace. When another agent touches a file involved in the turn, Mains marks the turn as shared and disables Undo. This prevents one agent’s reversal from removing another agent’s overlapping edits. Use separate worktrees for tasks that need independent files.

Availability

Change cards appear in Code and Work when there are file changes. Chat is read-only and does not show this control. Undo is a local file operation. It does not delete the conversation or reverse a published commit, PR, or external-service action.