Solana activated Transaction V1 on mainnet around 9:00 Beijing time on September 15, increasing the maximum size of a single transaction from 1,232 bytes to 4,096 bytes. The expansion allows developers to execute more complex atomic operations within one transaction, including enterprise multi-signature approvals, zero-knowledge proof applications, and multi-step transaction merging. The upgrade changes single-transaction data capacity but does not affect transactions per second; the old format remains usable for sending, while wallets and data services must adapt to read V1 transactions.