How to rewind and branch¶
Reyn's time-travel lets you rewind to a past checkpoint and optionally branch from that point. This guide covers the available commands and UI.
For how it works under the hood, see Time-Travel concepts.
Open the rewind picker¶
This opens an interactive checkpoint timeline in the TUI. Each row shows:
| Column | Description |
|---|---|
| seq | Global sequence number of the checkpoint |
| time | Timestamp when the checkpoint was created |
| kind | Boundary type: turn / plan-step / phase |
Navigate with ↑ / ↓, select with Enter. Press Esc to close without rewinding.
Shortcut: double-tap Esc Esc from anywhere in the TUI to open the picker directly.
Rewind to a specific seq¶
Rewinds directly to seq N without opening the picker. The agent's conversation state is restored to seq N. User workspace files remain at HEAD — Reyn time-travels its own .reyn/ state only.
Navigate the branch tree¶
After any rewind or fork, the picker switches to a tree view showing all branches. Each branch is labeled with its anchor checkpoint. Use ↑ / ↓ + Enter to select a checkpoint on any branch — active or abandoned.
- Selecting a seq on the current branch: undo (rewinds the current branch).
- Selecting a seq on an inactive branch: fork-switch (activates that branch).
Web edit (Phase 2d)¶
When using Reyn through the web interface (WebSocket / A2A), /rewind opens the same checkpoint picker. After selecting a checkpoint to branch from, the web edit flow presents the original message for you to retype your edited version and submit — inline prefill is not supported in the web surface, so you enter the replacement text directly. Submitting creates a new fork from the rewound checkpoint.
Pending features¶
| Feature | Status |
|---|---|
/rewind with in-turn edit (ctrl+t) to create a new fork-and-edit branch |
✅ Phase 2c, landed |
Retention window config (retention: keep_generations: N) to GC old checkpoints |
⏳ designed, not yet wired |
/rewind picker over WebSocket / A2A web surface; web edit via AskUserMessage UX |
✅ Phase 2d, landed |