the SIP-033 and SIP-034 proposals have been officially activated at Bitcoin block height 923222, and the Bitcoin smart contract layer Stacks has simultaneously launched the Clarity 4 smart contract language.

This upgrade adds six core new features for developers: obtaining and verifying on-chain contract code hashes, setting custom post-conditions for contracts, converting simple values to ASCII strings, obtaining the current block timestamp, secp256r1 signature verification (supporting native key integration), and a dimensional resource term extension mechanism. These features will lower the development threshold for native Bitcoin DeFi applications, help build safer and more flexible financial protocols, and further strengthen Stacks' positioning as the liquidity layer of the Bitcoin ecosystem. All Stacks transactions are settled on the Bitcoin chain, relying on the transfer proof mechanism to obtain Bitcoin network security guarantees.