Sei v6.7.1 patches the FlatKV state migration and asks pacific-1 nodes to update first

Victoria Shinder11 October 2026, 09:392 min read

Sei published v6.7.1 of its node software, seid, on 8 October, a patch on top of v6.7.0 aimed at one operation: the migration of EVM state from memIAVL to a new store, FlatKV. The release is not mandatory, but the Sei team asked validators and node operators on mainnet, pacific-1, to install it before the migration began, timed for about 17:00 UTC on 9 October when the migration proposal was set to pass. The testnet, atlantic-2, had already migrated on 1–2 October.

Compatibility. There is no governance proposal and no coordinated chain halt. The notes say there are no consensus-breaking changes and the AppHash does not change, so nodes on v6.7.0 and v6.7.1 stay in consensus; v6.7.0 nodes simply do not get the fixes.

What it fixes. The notes count eight fixes and one removal. Most concern the migration and the state-commit store:

• Data races and rollback problems in the state commit store, which matter to validators: the composite store's router and its write mode are now switched atomically, the write mode is re-derived on rollback, and a floor guards FlatKV rollbacks.
• Wrong contract nonces after state sync. A node that state-synced in the middle of the migration could end up with nonce 0 for some contracts. The fix stops this happening, but does not repair nodes already affected: operators whose node state-synced during the migration are told to state-sync again after updating.
• Iteration consistency: duplicates during composite iteration now resolve to memIAVL, matching how reads already behaved.
• Validation of module names in the memIAVL snapshot importer.

Two checks before updating.

1. seid export is gone. The deprecated genesis-export command was removed; scripts that call it will break. seid init, collect-gentxs and genesis import are unchanged.
2. Pinned write modes now fail loudly. Operators who set sc-write-mode-enable-auto = false and pin sc-write-mode to one of the migration modes will find the node refuses to start if the pinned mode disagrees with the migration state on disk. Previously such a node started and then diverged from the network. The fix offered is to set sc-write-mode-enable-auto = true in the [state-commit] section of app.toml.

The second change is the more instructive one. A setting that silently put a node on a different state than its peers has been turned into a start-up failure — the same trade every infrastructure team makes when a quiet divergence is worse than a visible outage.

For nodes not yet at the v6.7 upgrade height on pacific-1 (block 236,450,000, proposal 125), v6.7.1 can be used directly for the upgrade in place of v6.7.0. Pre-built static binaries for linux/amd64 and linux/arm64 are attached with a checksum file.

Source: Sei v6.7.1 release notes, 8 October 2026 — https://github.com/sei-protocol/sei-chain/releases/tag/v6.7.1