Release notes

[!IMPORTANT] This release is mandatory for all testnet operators for the upcoming Fusaka hard fork. It includes protocol changes and fixes required to remain in consensus on testnets. - Holesky: Wednesday, October 1, 2025 at 8:48:00 AM UTC - Sepolia: Tuesday, October 14, 2025 at 7:36:00 AM UTC - Hoodi: Tuesday, October 28, 2025 at 6:53:12 PM UTC

Fusaka Testnets Support

• Implemented Osaka testnet forks (#9321).
• Updated RPC behavior: eth_getBlobsV1 now returns UnsupportedFork post-Osaka (#9341).
• Fixed eth_config: ensured ForkInfo is always initialized (#9233).

Stability and Sync Improvements

• Fixed snap sync edge cases and hanging on Sepolia (#9166, [#9338]).
• Corrected blockhash handling and rare invalid block cases (#9340).
• Improved cancellation handling and graceful shutdown for peers and sync dispatcher (#9173, [#9174], [#9175]).
• Fixed concurrent storage root issues and reduced reliance on storage root reads (#9209, [#9255]).
• Ensured consistent receipts handling and transaction processed counters (#9231, [#9270]).
• Fixed issues in Taiko fee handling and default chains config (#9314, [#9309]).
• Fixed missed SELFDESTRUCT between transactions (#9343).

Node Improvements

• Reduced log noise from misbehaving peers and improved shutdown logging (#9156, [#9177]).
• Improved logging and config autocompletion (#9159).
• CLI now displays default values in help output (#9152).
• Improved deposit request validation (#9199).
• Enhanced Prometheus metrics in Kute tool (#9077).
• Better RPC alignment with Geth (#8951).
• Various performance optimizations: bloom filters, Patricia trie, TrieNode navigation, gas estimation (#9191, [#9220], [#9221], [#9195], [#9064], [#9210]).

These changes strengthen node stability, improve operator experience, and ensure readiness for the Fusaka fork on testnets.

What's Changed

• Correctly Wrap PrepareRequest exeception by @benaadams in https://github.com/NethermindEth/nethermind/pull/9144
• Only update metrics if not already updating metrics by @benaadams in https://github.com/NethermindEth/nethermind/pull/9142
• fix: BlockReceiptsTracer not forwarding stateRoot to inner tracers by @radik878 in https://github.com/NethermindEth/nethermind/pull/9129
• Make CLI show default values in help output by @Copilot in https://github.com/NethermindEth/nethermind/pull/9152
• Don't serialize UI events when no subscribers by @benaadams in https://github.com/NethermindEth/nethermind/pull/9150
• Fix storage range not retried on wrong order by @asdacap in https://github.com/NethermindEth/nethermind/pull/9154
• Reduce log noise from bad behaving peers by @benaadams in https://github.com/NethermindEth/nethermind/pull/9156
• Don't crash process in debug for Disposal warning messages by @benaadams in https://github.com/NethermindEth/nethermind/pull/9157
• Base mainnet bigger machine by @kamilchodola in https://github.com/NethermindEth/nethermind/pull/9158
• Improve logs and config autocompletion by @flcl42 in https://github.com/NethermindEth/nethermind/pull/9159
• Add a EIP and remove genesis number in superchain.py by @flcl42 in https://github.com/NethermindEth/nethermind/pull/9143
• Add Vector256 nibble conversion by @benaadams in https://github.com/NethermindEth/nethermind/pull/9153
• Use multi-arch vectors for Or and Xor; and expand to 512 bits by @benaadams in https://github.com/NethermindEth/nethermind/pull/9164
• Fix snap sync edge case due to unnecessary proof by @asdacap in https://github.com/NethermindEth/nethermind/pull/9166
• Auto-update fast sync settings by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9147
• Use single event subscription for NewPayload by @benaadams in https://github.com/NethermindEth/nethermind/pull/9107
• Always output logs for processed blocks by @benaadams in https://github.com/NethermindEth/nethermind/pull/9170
• Handle Cancellation in SyncPeerPool.Allocate by @benaadams in https://github.com/NethermindEth/nethermind/pull/9173
• Extra validation in case IForwardHeaderProvider skip header. by @asdacap in https://github.com/NethermindEth/nethermind/pull/9171
• Cancel sync dispatcher loop on cancellation by @benaadams in https://github.com/NethermindEth/nethermind/pull/9174
• Handle peers shutdown more gracefully by @benaadams in https://github.com/NethermindEth/nethermind/pull/9175
• Remove unsupported Rlpx channel option by @benaadams in https://github.com/NethermindEth/nethermind/pull/9172
• More graceful shutdown logs by @benaadams in https://github.com/NethermindEth/nethermind/pull/9177
• Support OP Isthmus at the Genesis block by @emlautarom1 in https://github.com/NethermindEth/nethermind/pull/9163
• Explicitly pass parent header in header validator by @asdacap in https://github.com/NethermindEth/nethermind/pull/9168
• Cleanup/remove MaybeParent. by @asdacap in https://github.com/NethermindEth/nethermind/pull/9169
• Update OP Superchain chains by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9148
• Align/refactor RPC output with geth by @ak88 in https://github.com/NethermindEth/nethermind/pull/8951
• Optimize Blooms by @benaadams in https://github.com/NethermindEth/nethermind/pull/9191
• Auto-update fast sync settings by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9193
• Update OP Superchain chains by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9194
• Per contract state by @asdacap in https://github.com/NethermindEth/nethermind/pull/9088
• Use genesis as the parent for the first block by @flcl42 in https://github.com/NethermindEth/nethermind/pull/9203
• Improve deposit request fields validation by @flcl42 in https://github.com/NethermindEth/nethermind/pull/9199
• Refactor/move main blockprocessing to di by @asdacap in https://github.com/NethermindEth/nethermind/pull/9130
• Start XDC project by @ak88 in https://github.com/NethermindEth/nethermind/pull/9206
• Optimize TrieNode.SeekChild by @benaadams in https://github.com/NethermindEth/nethermind/pull/9195
• Fix concurrent storage root issue by @asdacap in https://github.com/NethermindEth/nethermind/pull/9209
• Incorrect Gas Estimation by @svlachakis in https://github.com/NethermindEth/nethermind/pull/9064
• GasEstimator refactor post [#9064] by @LukaszRozmej in https://github.com/NethermindEth/nethermind/pull/9210
• Added basic spec classes by @ak88 in https://github.com/NethermindEth/nethermind/pull/9212
• Await db blocks sync inside ReviewBlockTree by @deffrian in https://github.com/NethermindEth/nethermind/pull/9196
• Remove hardcoded AuRa release spec decorator to plugin module by @asdacap in https://github.com/NethermindEth/nethermind/pull/9167
• Auto-update fast sync settings by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9217
• Update OP Superchain chains by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9218
• Precompiles Extensibility through IReleaseSpec by @svlachakis in https://github.com/NethermindEth/nethermind/pull/9222
• feat: improve kute tool prometheus metrics by @cbermudez97 in https://github.com/NethermindEth/nethermind/pull/9077
• Hive to load blocks before RPC start by @flcl42 in https://github.com/NethermindEth/nethermind/pull/9224
• Refactor/move blocktree to di by @asdacap in https://github.com/NethermindEth/nethermind/pull/9230
• Admin Get Peers by @svlachakis in https://github.com/NethermindEth/nethermind/pull/9003
• Fix receipts deletion by @Marchhill in https://github.com/NethermindEth/nethermind/pull/9231
• ENR Support on admin_peers by @svlachakis in https://github.com/NethermindEth/nethermind/pull/9228
• Ensure ForkInfo is initialized by @flcl42 in https://github.com/NethermindEth/nethermind/pull/9233
• feat(block-validator): add debug logging message for MaxRlpBlockSize by @0xMushow in https://github.com/NethermindEth/nethermind/pull/9236
• Implement Xdc Header Decoder by @cicr99 in https://github.com/NethermindEth/nethermind/pull/9214
• Remove unused references for XDC by @ak88 in https://github.com/NethermindEth/nethermind/pull/9237
• Corrected sealing encoding XDC by @ak88 in https://github.com/NethermindEth/nethermind/pull/9238
• Removed xdc ref in core by @ak88 in https://github.com/NethermindEth/nethermind/pull/9242
• XDC : add extra needed types by @Demuirgos in https://github.com/NethermindEth/nethermind/pull/9219
• implement eth_getAccountInfo by @smartprogrammer93 in https://github.com/NethermindEth/nethermind/pull/9241
• Added filename in accumulator.txt and checksums.txt by @ndatta-nethermind in https://github.com/NethermindEth/nethermind/pull/9211
• Cleanup/remove nodecommit info by @asdacap in https://github.com/NethermindEth/nethermind/pull/9155
• Fix Nethermind UI when the app is run from non-app directory by @wurdum in https://github.com/NethermindEth/nethermind/pull/9248
• Fix simulate gas by @deffrian in https://github.com/NethermindEth/nethermind/pull/9244
• Cleanup/remove unnecessary method by @asdacap in https://github.com/NethermindEth/nethermind/pull/9249
• Tests for [#9244] by @deffrian in https://github.com/NethermindEth/nethermind/pull/9250
• Perf/Patricia set by @asdacap in https://github.com/NethermindEth/nethermind/pull/9220
• Perf/Update Patricia.Get by @asdacap in https://github.com/NethermindEth/nethermind/pull/9221
• Auto-update fast sync settings by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9252
• Update OP Superchain chains by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9253
• Bump up the version to 1.34.0-unstable by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9124
• Feature/arbitrum setup sync by @damian-orzechowski in https://github.com/NethermindEth/nethermind/pull/9232
• Reduce use of storage root slightly by @asdacap in https://github.com/NethermindEth/nethermind/pull/9255
• Clear storage cell / trie without reading cell's value first fails by @damian-orzechowski in https://github.com/NethermindEth/nethermind/pull/9239
• fix inconsistent merge plugin test by @asdacap in https://github.com/NethermindEth/nethermind/pull/9258
• Required decoders for XDC by @ak88 in https://github.com/NethermindEth/nethermind/pull/9257
• Perf/PatriciaTree bulk set by @asdacap in https://github.com/NethermindEth/nethermind/pull/9215
• Refactor/Use genesis loader in test by @asdacap in https://github.com/NethermindEth/nethermind/pull/9259
• Cleanup/move TransactionProcessed event to IMainProcessingContext by @asdacap in https://github.com/NethermindEth/nethermind/pull/9271
• Fix transaction processed counter not working by @asdacap in https://github.com/NethermindEth/nethermind/pull/9270
• Use extension method in some ITransactionProcessor interface method. by @asdacap in https://github.com/NethermindEth/nethermind/pull/9272
• Remove from GitHub Actions energyweb and volta chains sync by @stdevMac in https://github.com/NethermindEth/nethermind/pull/9256
• Genesis extensibility by @svlachakis in https://github.com/NethermindEth/nethermind/pull/9282
• Enable passing args to Nethermind when using sync chains pipeline by @flcl42 in https://github.com/NethermindEth/nethermind/pull/9184
• Update OP Superchain chains by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9284
• Auto-update fast sync settings by @core-repository-dispatch-app[bot] in https://github.com/NethermindEth/nethermind/pull/9283
• Select proper block by @flcl42 in https://github.com/NethermindEth/nethermind/pull/9289
• Fix selfdestruct missed between transaction by @asdacap in https://github.com/NethermindEth/nethermind/pull/9343
• Fix Issues in Taiko Fee Handling by @dipkakwani in https://github.com/NethermindEth/nethermind/pull/9314
• Fix Taiko Chains Default Config by @dipkakwani https://github.com/NethermindEth/nethermind/pull/9309
• Make eth_getBlobsV1 return UnsupportedFork post Osaka by @LukaszRozmej in https://github.com/NethermindEth/nethermind/pull/9341
• Fix blockhash related random invalid block by @asdacap in https://github.com/NethermindEth/nethermind/pull/9340
• Fix MCL memory leak by @rubo in https://github.com/NethermindEth/nethermind/pull/9336
• Fix hanging sepolia snap sync by @asdacap in https://github.com/NethermindEth/nethermind/pull/9338
• Osaka testnet forks by @Marchhill in https://github.com/NethermindEth/nethermind/pull/9321

New Contributors

• @radik878 made their first contribution in https://github.com/NethermindEth/nethermind/pull/9129
• @0xMushow made their first contribution in https://github.com/NethermindEth/nethermind/pull/9236
• @ndatta-nethermind made their first contribution in https://github.com/NethermindEth/nethermind/pull/9211

Full Changelog: https://github.com/NethermindEth/nethermind/compare/1.33.1...1.34.0