OP_CAT has formally received a Bitcoin Improvement Proposal number, BIP-420, as the ongoing debate surrounding covenants on Bitcoin continues.

“Today, after a long wait, the OP_CAT proposal formally received a BIP number. Meet BIP-420!,” OP_CAT advocate and co-founder of Taproot Wizards Udi Wertheimer posted late Monday. “BIP-420 enables covenants on bitcoin, allowing for smart contracts, secure bridges, on-chain trading, zk proof verification and more.”

Generally speaking, covenants on Bitcoin are advanced scripting features that allow for specific conditions on how bitcoins can be spent in future transactions. They could enable use cases, including the creation of secure "vaults" that allow reversible transactions, automated recurring payments, time-locked transfers for scenarios like …