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Deterministic JavaScript execution.

Run JavaScript that replays byte-for-byte, forks a live heap, and proves exactly what it did. One runtime — replayable, forkable, provable.

replayable — same in, same out, forever forkable — branch a warm heap N ways provable — a signed receipt per run

Built for AI agents that write & run code · eval platforms scoring customer functions · products running customer formulas, plugins & untrusted JS

2026 is the year running other people's code got dangerous.
axios → RAT @antv → CI/CD theft Cline → token exfil Vercel → env leak Red Hat npm → backdoored
Every one lands through a step the box doesn't have — an install, a lifecycle script, an ambient socket, a plaintext secret. No surface here.