Sui’s mainnet release 1.79.1, published on September 9, 2026, introduces protocol versions 135 and 136 and a suite of changes that tighten transaction handling and improve node‑level security.
Version 135 disables the legacy defer_unpaid_amplification flag on mainnet and applies the original_package_id cost model and consensus block limits that were previously only active on v134. Version 136 carries forward the pending features from v135, including a hard‑coded 10 MB limit on the package arena size used by the Move VM.
A key addition is the TransactionExpiration::Validity feature, which limits a transaction to a named set of consensus proposers. When enabled behind the allowed_proposers flag (currently active only on devnet), the transaction’s validity is tied to specific validators. Parallel to this, the ptb_tx_context_restrictions flag (protocol version 135) enforces that a TxContext in a PTB Move call can appear only as &mut or & references, never by value or in the return position. Violations now trigger an InvalidTxContext error immediately, replacing the older, more opaque borrow‑check or serialization failures.
Node‑level changes complement the protocol updates. Full nodes now submit proposer‑restricted transactions only to the validators they name, eliminating the need for configuration changes and ensuring that transactions are routed correctly. Validators and full nodes benefit from the stricter transaction validation without altering existing transaction flows.
The release also updates the RPC interfaces. The gRPC SimulateTransaction method now returns a VALIDITY expiration that includes the list of allowed proposers, replacing the previous VALID_DURING response. Clients that reconstruct transaction expirations must propagate the new allowed_proposers field to maintain digest consistency. JSON‑RPC and GraphQL indexers have been tightened: the sui‑indexer‑alt‑jsonrpc and sui‑indexer‑alt‑graphql tools no longer accept legacy Bigtable flags and now require a ledger‑grpc‑url, preventing accidental fallback to Postgres for key‑value lookups.
Collectively, these changes enhance Sui’s security posture, provide clearer error reporting for developers, and streamline node configuration. By binding transactions to specific proposers and tightening context rules, Sui reduces the attack surface and improves the reliability of the network’s consensus process.