Definition
A Bitcoin vault is a custody construction that adds a mandatory delay and a recovery path to the spending of coins, so that a theft attempt can be detected and reversed before it settles. Rather than a single key directly controlling funds, a vault requires a withdrawal to first be "triggered," after which a time delay elapses before the coins can actually move. During that window, the rightful owner can use a separate recovery key to "claw back" the funds — sweeping them to safety even if the primary keys have been compromised.
Trigger, delay, and clawback
A typical vault flow has three stages: an unvaulting (or trigger) transaction that begins a withdrawal, a delay period enforced by the script during which the spend is pending, and either a normal completion to the intended destination or a clawback that revaults the coins. The delay gives a human or monitoring system time to notice an unexpected withdrawal and intervene, shifting Bitcoin custody from "a stolen key means instant, irreversible loss" toward a model with a safety net.
How vaults are built
Vaults can be approximated today using pre-signed transactions and timelocks, but these are operationally fragile. Dedicated covenant opcodes aim to make them robust and flexible: BIP345's OP_VAULT proposes vault-specific covenants with delayed unvaulting and dynamic withdrawal targets, while OP_CHECKTEMPLATEVERIFY can express simpler fixed-template vaults. These remain proposals pending a consensus change.
Vaults are a flagship motivation for covenant research. See OP_CHECKTEMPLATEVERIFY (CTV) and the covenant entry for the underlying mechanisms.
In Simple Terms
A Bitcoin vault is a custody construction that adds a mandatory delay and a recovery path to the spending of coins, so that a theft…