Mysten Labs published Sui mainnet-v1.82.3 on 21 October. Its release notes say mainnet protocol version 138 reduces the non-refundable portion of the storage fee from 1% to 0.01% of the storage rebate. The binary also removes the legacy JSON-RPC service from the full node and adds newer gRPC, GraphQL and signature-handling changes.

The distinction between software availability and network activation matters. The merged mainnet protocol-138 change says validators vote on upgrades using a configuration digest, and mainnet cannot move to version 138 until a quorum runs a compatible configuration. NetNapz did not independently query the validator set or confirm the active protocol version when this report was checked.

What the storage-fee change does

Sui charges for object storage and returns a storage rebate when data is deleted. The release changes the share retained by the protocol from 1% to 0.01% of that rebate. It does not eliminate transaction gas, storage charges or execution costs, and it does not imply a 99% reduction in every user’s total fee.

The implementation notes show why operators need matching software. An earlier 1.81 build without the patched protocol-138 configuration would compute a different configuration and could fork after activation. Version 1.82.3 contains the mainnet setting, while protocol version 139 carries the same lower rate for other environments.

JSON-RPC removal changes the operating surface

The release removes the JSON-RPC service from the full node. Its notes say the old database is deleted on startup to free disk space. Operators and application teams that still depend on that local service should verify their migration to supported gRPC or GraphQL paths before upgrading production infrastructure.

This is an infrastructure change rather than a shutdown of Sui’s network. The release also adds a consistent-read checkpoint header to the key-value RPC service and expands transaction and checkpoint subscription responses when requested through read masks.

Post-quantum signature support has a narrower meaning

Version 1.82.3 adds ML-DSA-65 signature and public-key types to gRPC, GraphQL and the Rust SDK. The release says submitted ML-DSA-65 signatures and multisig members can be verified through the transaction APIs. This API support does not establish a network-wide migration of accounts, validators or consensus cryptography to post-quantum signatures.

NetNapz assessment

Assessment: the storage-rebate change is economically relevant for applications that create and later delete large amounts of onchain state, but the effect should be measured against their complete gas and storage bills. The stronger near-term operational issue is client compatibility: nodes need the matching protocol configuration, and teams using the removed JSON-RPC service need a tested replacement path.

Evidence to watch includes an official confirmation that protocol 138 activated on mainnet, validator adoption of compatible binaries, migration reports from JSON-RPC users and measured changes in storage-heavy application costs. None of those should be inferred solely from the release tag.

Sources

Mysten Labs — mainnet-v1.82.3 release, published 21 October 2026; checked 22 October 2026.

Mysten Labs pull request #28233 — mainnet protocol-138 storage-rebate configuration, merged 6 October 2026; checked 22 October 2026.

Mysten Labs pull request #27907 — full-node JSON-RPC removal, merged 25 September 2026; checked 22 October 2026.

NetNapz reporting and assessment. No live SUI price, flow or performance claim is made.