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Smart Contracts

Advanced contract capabilities. 8 proposals.

  • BIP 114: Merkelized Abstract Syntax Tree: Closed. Proposed MAST, which organizes a script's possible spending conditions into a tree so that only the condition actually used needs to be revealed. This saves space and improves privacy by hiding…
  • BIP 116: MERKLEBRANCHVERIFY: Draft. Proposed MERKLEBRANCHVERIFY, a script instruction that checks whether a piece of data belongs to a committed set using a Merkle proof. It would let complex contracts reveal only the spending…
  • BIP 117: Tail Call Execution Semantics: Draft. Proposed letting a script hand off execution to another script supplied at spending time, a 'tail call'. Combined with BIP 116, this would allow contracts with many possible spending conditions…
  • BIP 118: SIGHASH_ANYPREVOUT for Taproot Scripts: Draft. Proposes SIGHASH_ANYPREVOUT, a signature type for Taproot scripts that does not commit to the exact coin being spent, so one signed transaction can be attached to any compatible coin. This would…
  • BIP 119: CHECKTEMPLATEVERIFY: Draft. Proposes CHECKTEMPLATEVERIFY, a script instruction that restricts coins so they can only be spent in a transaction matching a predetermined template. This 'covenant' could enable vaults that protect…
  • BIP 199: Hashed Time-Locked Contract transactions: Closed. Defines the hashed time-locked contract (HTLC), a script where funds can be claimed by revealing a secret before a deadline or reclaimed by the sender afterward. HTLCs are a core building block for…
  • BIP 300: Hashrate Escrows (Consensus layer): Draft. Proposes "hashrate escrows," which would let bitcoin move to and from sidechains with withdrawals approved gradually by miners over months rather than by a trusted federation. The goal is to allow…
  • BIP 341: Taproot: SegWit version 1 spending rules: Deployed. Taproot introduces a new kind of Bitcoin output that can be spent either with a single signature or by revealing just one of many possible alternative spending conditions, kept hidden in a tree…