You do not have to remember to save before a restyle. Delta takes the snapshot for you, on every successful design write, capturing what the design system looked like a moment before.
See them under Delta → Design.
What is captured
The design system: tokens, site.css, components.css, site.js, notes and component recipes. Each snapshot records why it was taken: a token change, a stylesheet write, a notes edit. A list of them reads as a history of the design.
Pages, templates and content are not in a snapshot. Those have WordPress revisions of their own.
Going back
“Show me the design snapshots from today.”
“Restore the design system to the state before the restyle.”
The agent confirms before restoring, because a restore replaces the live design system.
Restores are reversible
A restore snapshots the current state before it replaces anything. To return to the state you just left, restore that snapshot.
How many are kept
Delta keeps the fifty most recent snapshots. The oldest is removed as new ones arrive.
You can also take a snapshot yourself and give it a label, such as a design signed off by a client. Labelled snapshots count toward the same limit. To keep a state beyond that, download the design system.
For developers
Snapshots live under uploads/21press-delta/snapshots, each carrying a reason such as tokens, site-assets, notes or manual. A restore writes one with the reason before-restore before it replaces anything.