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TERM_DEF // UPGRADES_BIPS / OP_VAULT_BIP_345
OP_VAULT (BIP
345)
OP_VAULT (BIP 345). Proposed vault primitive enabling timelocked recovery flows on-chain.

This page sits in the Upgrades & BIPs section — The proposal process and the major upgrades that shaped Bitcoin. Read on for what it is, why it exists, how it works under the hood, and what to watch out for.
OP_VAULT (BIP 345) — at a glance
UPGRADES
BIP 345 is a proposal in the Script family, first published in 2023 with status draft (fork/">soft fork). Proposed vault primitive enabling timelocked recovery flows on-chain. Its technical mechanism: OP_VAULT + OP_VAULT_RECOVER — multi-step delayed withdrawal with abort. vault constructions; not yet activated
Why it exists
DESIGN
OP_VAULT (BIP 345) exists to solve a specific problem: covenants — restrict where coins can be sent in their next hop. Without a written, numbered spec, every wallet and node implementer would interpret the requirement differently — and Bitcoin's value depends on every implementation agreeing exactly. BIP-345 is the single source of truth for this concern, so any new client built today can match the behaviour of every client built since 2023.
Mechanism
HOW IT WORKS
Mechanically, BIP-345 oP_VAULT + OP_VAULT_RECOVER — multi-step delayed withdrawal with abort. Because this is a soft fork, old software accepts new behaviour without modification — but new behaviour is rejected if old software produces it. Adoption today: vault constructions; not yet activated.
1. Author drafts BIP-345 against the BIP-2 template — abstract, motivation, specification, rationale. 2. The text + a reference implementation are posted on the bitcoin-dev list and as a PR to bitcoin/bips. 3. Reviewers tear it apart: ambiguities, security concerns, edge cases, interaction with prior BIPs. 4. Once stable, the BIP editor merges it; it gets a number (BIP-345) and the status "draft" or "proposed". 5. Implementations land in Bitcoin Core / wallets / other clients. For consensus changes: activation parameters chosen. 6. After deployment + adoption, BIP-345 is promoted to "final"; deprecated proposals get "replaced" or "withdrawn".
BIP-345 — quick reference card
EXAMPLE
BIP number : 345 Title : OP_VAULT (BIP 345) Area : Script First published: 2023 Status : draft Fork class : soft Motivation : covenants — restrict where coins can be sent in their next hop. Mechanism : OP_VAULT + OP_VAULT_RECOVER — multi-step delayed withdrawal with abort. Where it shows up : vault constructions; not yet activated. Read the spec : https://github.com/bitcoin/bips/blob/master/bip-0345.mediawiki
OPT-IN
No authority can force a BIP on anyone. Adoption depends entirely on whether the change is genuinely useful.
NUMBERED
Stable numeric reference — BIP-345 means the same thing across every wallet, miner, and node that has read this spec.
BIP-345 is a soft fork — it changes (or proposes to change) the rules every full node enforces.
DRAFT
BIP-345 is still in draft — reference code may exist but mainnet adoption is partial or pending.
Things that catch people out
PITFALLS
  • BIP-345 is still in DRAFT status — its details can change before activation, and any code built against it may need adjustment.
  • BIP-345 is a soft fork — old clients accept new behaviour but don't enforce it. Validate against an upgraded node to be sure the rule is being checked.
  • Don't confuse "draft" / "proposed" / "final" status — read the BIP header before relying on it in production.
  • The BIP number is just an editorial counter — it doesn't imply correctness or stability. Always cross-reference with the latest bitcoin/bips repo.

TERMINOLOGY
OP_VAULT (BIP 345)
Proposed vault primitive enabling timelocked recovery flows on-chain.
Segregated Witness (SegWit, BIP 141)
The 2017 upgrade separating witness-data/">witness data, fixing tx malleability, and introducing weight units.
Taproot (BIP 341)
The 2021 upgrade introducing key-aggregable schnorr-signatures/">Schnorr signatures and Merkleized script trees.
Tapscript (BIP 342)
Script-language updates accompanying Taproot — new opcodes, removed limits.
Schnorr (BIP 340)
The Schnorr signature spec adopted by Taproot.
BIP Process
The community workflow for proposing, discussing, and tracking changes to Bitcoin.
Soft Fork Activation
The mechanism (versionbits, MASF, UASF, Speedy Trial) by which soft forks turn on.
MASF (Miner-Activated Soft Fork)
Activation triggered by miner signaling in block versions.