Blockstream's Adam Back Touts Covenant Opcodes as 'Last Soft-Fork' for Bitcoin

Adam Back, co-founder and CEO of Blockstream, has endorsed covenant opcodes as a potential 'last soft-fork' for Bitcoin. This proposal aims to reduce the frequency of future protocol changes while making Bitcoin Script more secure. Back's idea is rooted in two linked concepts: the potential for covenant-enabling tools to decrease the need for new soft forks and the use of formal semantics and mathematical proofs to harden Bitcoin Script.

Covenant opcodes would allow for rules to be attached to coins, restricting how they can be spent in the future. This would expand the functionality of Bitcoin Script, which currently only checks whether someone has the right to spend coins. Several proposals, including CTV (BIP 119) and OP_CAT (BIP 347), have been gaining attention in 2026 and are being tested on the signet network.

Back's comments referenced Simplicity, a smart-contract language developed by Blockstream, which was launched on the Liquid Network in 2025. Simplicity aims to deliver covenant-like functionality and was built with formal verification in mind, aligning with Back's emphasis on mathematical proofs for script security.

Back's statement carries no immediate market effects, but it signals a shift in the protocol-level debate. Developers are now watching signet activity and the progress of draft BIPs like BIP 119 and BIP 347, which could mark a genuine change in momentum.