Sui mainnet v1.81.1 brings protocol 138 and changes how validators pick transactions for blocks

Serguey Asael Shinder08 October 2026, 07:161 min read

Mysten Labs published Sui mainnet-v1.81.1 on 7 October, a day after the same build went to testnet. It carries Sui protocol version 138.

Protocol changes.

• Deferred transactions: colliding deferred-transaction keys in the consensus handler now merge their entries instead of overwriting them, so a transaction that is deferred again can no longer push out one deferred earlier (PR 28131).
• A new memory invariant check for reference and value usage in programmable transaction blocks (PR 27975).
• Gas model changes that the notes describe as implementation-only, with no user impact (PR 27049).
• Two changes are limited to devnet and testnet at protocol 138: transaction effects stop reporting transaction dependencies (the encoding keeps an empty vector), and the object-funds withdrawal check runs during execution.

For node operators — two defaults change.

• Validators now pull transactions from a consensus-side pool when they propose a block, instead of the admission queue pushing them in. The old behaviour stays available with consensus-transaction-pool.enabled: false (PR 28076).
• Full nodes no longer restrict simulated transactions to their preferred proposers; operators who want the old behaviour must set enable-simulate-allowed-proposers: true (PR 28037).

For developers. GraphQL gains multiGetDynamicFields, derived-object lookups and a nullable Balance.coinMetadata. Rosetta now fetches the latest checkpoint in one request, ending transient Checkpoint N not found errors behind load balancers. In sui move test, test_scenario now tracks funds across transactions, so a withdrawal from an object succeeds only up to what was actually sent to it. Tests that relied on the old behaviour, where every object withdrawal succeeded, will now abort.