OP_CAT
Protocol Upgrade
Opcode
OP_CAT, proposed in BIP-347 and activated on signet in 2024, re-enables concatenation of stack elements in Bitcoin Script, previously disabled by Satoshi Nakamoto. It supports complex smart contracts, covenants, and trustless bridges, with significant on-chain usage (74K transactions).
Status & Details
Testnet
BIP Reference
BIP-347
Impact Areas
Programmability
Efficiency