Version history keeps past versions of each AI analysis layer so you can revert to an earlier state. Every time an AI analysis run completes on a layer, the previous shapes are saved as a version. History is per layer and applies only to AI analysis layers — manual and default layers do not have history.

Open the layer dropdown in the takeoff toolbar, find the AI analysis layer you want, and click the overflow (...) menu next to it. Choose View history.

The dialog is titled history with the description "Each AI run saves the previous state as a version — revert to bring it back." Versions are listed newest first, labeled v1, v2, and so on. Each row shows how long ago it was saved (for example, 5m ago) and its shape count. The most recent version is marked before latest.

A new version is saved automatically each time an AI analysis run finishes on the layer. There is no time-based background autosave — versions exist only as a record of completed AI runs, so a layer with no runs has no history.

Each layer keeps its 10 most recent versions. When a new version pushes the count past that, the oldest is pruned automatically.

Each version row has a Revert button. Clicking it opens a confirmation titled Replace current shapes?. Confirm with Revert to replace the layer's current shapes with that version's, or Cancel to keep your current state.

Before the revert runs, the layer's current shapes are saved as a new version, so you can undo the revert by reverting again. On very large layers this pre-revert version may be skipped, so the revert is not undoable in that case.

A revert restores shapes whose symbols still exist. Any shape tied to a symbol that was deleted after the version was saved is not restored.

Anyone with project access can open View history and browse a layer's versions. Reverting requires edit access — viewers can look but cannot replace the current shapes.

Version history covers AI analysis layers only. To learn how those layers are created, see AI takeoffs and Layers.