Optimism 200 ms Subblocks Change Zeroes Payload Roots
Optimism shortens OP Mainnet subblock interval to 200 ms and zeroes state_root, block_hash and withdrawals_root fields, requiring direct consumers to execute transactions for preconfirmed state.
Optimism plans to cut the subblock preconfirmation interval on OP Mainnet from 250 ms to 200 ms, with rollout targeted for Aug. 31.
The sequencer will continue to emit payloads of type ExecutionPayloadFlashblockDeltaV1, but state_root, block_hash and withdrawals_root will be set to all-zero values while withdrawals will be an empty list.
receipts_root and logs_bloom will remain populated with real data.
Direct stream consumers must now derive preconfirmed state by executing the transactions carried in the stream rather than reading the placeholder roots.
Applications that rely on standard RPC providers with the pending tag are unaffected provided the provider maintains its own derived state view.
The Aug. 31 target may move and the rollout is gradual with no network-wide completion date documented.