Optimism - Blocks produced not being distributed to the network – Incident details

All systems operational

Blocks produced not being distributed to the network

Resolved
Major outage
Started about 2 months agoLasted about 2 hours

Affected

Mainnet

Partial outage from 6:03 PM to 6:23 PM, Operational from 6:23 PM to 7:35 PM

Transaction Sequencing

Partial outage from 6:03 PM to 6:23 PM, Operational from 6:23 PM to 7:35 PM

Updates
  • Postmortem
    UTC
    Postmortem

    OP Mainnet external nodes and RPC providers stalled on a stale head (7 July 2026)

    Status: Resolved


    Impact

    External nodes and third-party RPC providers were stuck at a stale head for ~22 minutes (17:59 to 18:22 UTC). Because major providers were serving that stale head, transaction throughput was near zero for about 16 minutes of that window, and submissions routed through those providers did not land. Reads continued to be served, though against a stale state. There was no reorg, no safe-head or finality violation, and no funds were at risk.


    Root cause

    A routine infrastructure upgrade disrupted a network connection our sequencers depend on. The connection failed silently rather than erroring, which throttled block production and pushed new blocks outside the window for normal peer-to-peer propagation. External nodes recovered once the affected range was posted to L1


    Remediation

    We deployed a fix removing the dependency responsible for the slowdown and made the affected connections fail cleanly when infrastructure cycles. We're also strengthening internal alerting and node peering so issues of this kind are detected and contained faster.

  • Resolved
    UTC
    Resolved
    This incident has been resolved.
  • Monitoring
    UTC
    Monitoring

    Most infrastructure providers have recovered, we are continuing to monitor and work with infrastructure providers to resolve syncing issues.

  • Investigating
    UTC
    Investigating

    We are currently investigating this incident after a brief unsafe head stall. The sequencer is now producing blocks but some nodes participating in the network are not syncing.