Versions and history
Each artifact keeps a numbered history of its content. Approval freezes the current version; after that, the version cannot be edited. Starting a new draft, pressing New Version on an approved artifact, or returning a draft from review opens the next numbered version.

What freezes a version
Approving an artifact locks the content of its active draft version. That version becomes the artifact's approved record. The artifact reverts to draft status when you create a new version from it.
The content of a version cannot be changed once it is in review. Attempting to save while the artifact is in review shows a message: the reviewer must request changes before you can save.
Comparing versions
When an artifact has more than one version, View Changes is available from the overflow menu (⋮). It opens a side-by-side diff of the two most recent versions. At version 1, the item is disabled and shows: "Only one version exists."
Starting a new version
Press New Version in the header when the artifact is Approved or Locked. The button shows Creating... while the draft is prepared. The new draft starts from the approved content and receives the next version number.
Returning a draft from review also advances the version counter. See Review and approve artifacts for the request-changes flow.
Restoring an earlier version
Open the Version property in the properties sidebar to see the full version list. Each row other than the current one has a restore icon. Pressing it copies the historical version's content into a new draft with the change summary "Restored from version N". The restore is non-destructive: the full history is preserved and the restored content goes through the normal review and approval pipeline before it becomes the approved record.
A superseded artifact shows Restore in the header. Pressing it works the same way.
From the terminal
FAQ
What happens to the knowledge base when I create a new version?
The approved content stays in the knowledge base while the new draft is in progress. The knowledge base updates when the new version is approved, replacing the previous version's indexed content. You can also trigger re-indexing at any time with Re-run RAG in the overflow menu.
Does restoring a version change the artifact's status?
Yes. Restoring creates a new draft from the historical content, so the artifact returns to draft status and must go through review and approval again before the restored content is approved.