Optimism recommends op-node v1.19.8 for sequencers before Glamsterdam

Optimism has released opnode v1.19.8 and is advising sequencer operators to upgrade, especially those using the l2.follow.source setting. The update was published on October 1, 2026, and is aimed at improving Layer 2 node performance and upgrade safety. The main fix addresses slow block production during L1 origin changes. Optimism says opnode will now prefetch the next L1 head’s block and receipts as soon as the head is seen, which should reduce delays for sequencers that previously relied on later data fetching. If prefetching fails, the node will log a warning and continue with the normal path. The release also adds stricter checks for custom rollup configurations. opnode will now refuse to start if hardforks are configured out of order or if a later fork is activated at the same timestamp as the previous one. Optimism says chains already in the Superchain registry are not affected. Separately, Sepoliabased OP Stack operators must be on opnode v1.19.5 or later before the Glamsterdam hardfork on October 6.