Definition
OP_VAULT is a proposed covenant opcode described in BIP 345 by James O'Beirne (later co-authored with Greg Sanders). It is designed specifically to implement vaults: a self-custody pattern that adds a mandatory delay and a recovery path to any attempt to spend coins. OP_VAULT is a proposed soft fork and is not active on Bitcoin's base layer; it is one of several covenant ideas under review and is typically discussed together with a template-commitment primitive such as CTV.
How an OP_VAULT flow works
Coins held in a vault cannot be sent directly to an arbitrary destination. Instead, a withdrawal first moves them to an intermediate, partially specified state. During a predefined timelock window, the funds can be diverted back to a deep cold-storage wallet under the owner's control. Only after the delay elapses can they continue to the intended recipient. If an attacker who has compromised the hot key initiates a withdrawal, the legitimate owner sees the on-chain attempt and uses the recovery path before the timelock expires.
Why a dedicated opcode
Vaults can be approximated with pre-signed transactions or with CTV, but those approaches force awkward constraints: fixed denominations, fixed fees, address-reuse hazards, or the operational burden of securely deleting keys. OP_VAULT is designed to remove those limits, allowing flexible amounts and fees and safer deposit reuse, at the cost of a more specialized opcode.
OP_VAULT builds on the general notion of a Bitcoin vault and the covenant family described under covenants. This entry summarizes a proposal under discussion; D-Central does not predict whether or when it activates.
In Simple Terms
OP_VAULT is a proposed covenant opcode described in BIP 345 by James O’Beirne (later co-authored with Greg Sanders). It is designed specifically to implement vaults:…