An isolated machine, often a microVM, started for one AI agent so it can run code, browse and keep files without touching anything else.
Agent sandboxes turn 'an agent' into 'an agent with its own computer'. Providers start them in milliseconds and sell them by the thousand, some short-lived, some persistent for weeks.
Isolation answers one question: can the agent's code escape? It does not answer the buyer's other question: what is this machine running, and is it what I approved?
That second question is attestation. A persistent sandbox gets paused and resumed, snapshotted and forked, or updated in place. Each time, its earlier proof goes stale. That makes agent sandboxes a natural case for re-attestation.
Working on re-attestation for your product? A first call takes 30 minutes and commits you to nothing. Bring your product and the one question that worries you.
Next fixed date: EU Digital Identity Wallets are due in every member state on 24 December 2026, 42 days from now.