DeltaFS

DeltaBox: Millisecond-Level Sandbox Checkpoint/Rollback for Stateful AI Agents

DeltaBox introduces a new OS-level abstraction called DeltaState that enables change-based (delta) checkpoint and rollback for AI agent sandboxes, rather than duplicating full state on each operation. Two co-designed OS mechanisms—DeltaFS for filesystem state and DeltaCR for process state—reduce checkpoint latency to ~14ms and rollback to ~5ms, orders of magnitude faster than existing approaches. Evaluations on SWE-bench and RL micro-benchmarks demonstrate that agents can explore substantially more nodes under fixed time budgets, directly enabling deeper test-time tree search and large-scale RL fan-outs.