Protocol 22 is coming to Stellar Testnet on November 12 and will go to Mainnet validator vote on December 5. The upgrade introduces constructors for Soroban contracts (CAP-0058) and BLS12-381 cryptographic host functions (CAP-0059), enabling more efficient smart contracts and advanced privacy features like zk-SNARKs.
Stellar's Protocol 22 upgrade will arrive on Testnet November 12, 2024, followed by a Mainnet validator vote on December 5. The upgrade includes two major CAPs: CAP-0058 introduces constructors for Soroban smart contracts, automating contract initialization and reducing contract size, CPU usage, and storage while improving security against front-running attacks during deployment. CAP-0059 adds host functions for BLS12-381 elliptic curve cryptography, enabling pairing-based operations like zk-SNARKs directly in smart contracts without requiring developers to implement complex computations themselves. BLS12-381 support unlocks use cases such as anonymous authentication (zkLogin, zkEmail) where users can authenticate with Web2 identities without exposing personal information on-chain. The Stellar Development Foundation has published a Protocol 22 Upgrade Guide to help developers prepare their software, SDKs, RPC, Horizon, and Stellar Core implementations.
