Time-travel

Because the operation log is append-only and never rewrites history, every past state is still exactly reproducible. You can materialize the repo as of any earlier point by replaying the log up to that frontier.

Read-only checkout at a past frontier

fabric clone --at op:<actor>:<seq>

This gives you a detached, read-only checkout of the repo as it looked at that op. Op refs are actor:seq frontier coordinates, not content hashes.

Why it’s read-only

Fabric is forward-only: the only direction is append-at-the-frontier. You cannot go back to a historical frontier and fork new work from it the way Git lets you branch from an old commit. Time-travel lets you view the repo as of a past op (to inspect, audit, or compare), never to branch or edit from one.

To change anything, append at the current frontier: create a change, edit, and push (see the Quickstart).

What you can do with it

• Inspect exactly what a file looked like at a past point.
• Audit how the repo evolved, op by op.
• Compare a historical state against the current trunk.
• Share a permalink to a file or line range pinned to a past state: the web file browser’s “Copy permalink” uses these same op refs. See Share links.

Comments as of that version

Comments live in the same log, so a past checkout shows the comments that existed at that version, over the text they were written on. Rewind to an earlier frontier and you see exactly the threads open then: which had been created yet, and whether each was resolved at that point. You do not see a comment written later, and you do not see today’s comments re-anchored onto old text. A comment whose line was deleted after it was left reads as outdated against the snippet it quoted, rather than pointing at the wrong place.

Authorship travels with the ops themselves (carried on op-ids, not reconstructed), so blame and history stay accurate no matter how far back you look.