What happened.

Hydra PR #2769 changes SyncedStatusReport from a per-chain-tick message sent to every client into an edge-triggered report. Clients receive it when sync status changes, rather than continuously on every block-related tick.

The continuous observability work moves to Prometheus. Hydra now exposes hydra_chain_drift_seconds for chain drift and hydra_chain_last_block_timestamp_seconds for the last observed block time. Sync transitions remain available through NodeSynced and NodeUnsynced, while Greetings.chainSyncedStatus provides the initial status.

Why it matters.

Hydra client and monitoring integrators may need to adjust their expectations. Live drift is no longer available through the WebSocket between sync-state transitions, so monitoring that relied on per-tick SyncedStatusReport updates should instead use the Prometheus metrics.

The change is aimed at reducing a chatty stream of reports to connected clients while preserving separate signals for state transitions, drift, and backend stalls. It is an API behavior change, rather than a new user-facing capability.

What to watch next.

The most useful receipt is whether integrators update alerting and dashboards to use hydra_chain_drift_seconds for drift and hydra_chain_last_block_timestamp_seconds for stalls, alongside the transition events for sync state.

A key operational detail is that the drift gauge updates only when ticks are observed. During a complete chain stall it freezes rather than increasing, which is why the last-block-timestamp gauge is the intended stall signal.

What to watch

Watch for downstream client and monitoring updates that replace per-tick WebSocket drift handling with the two Prometheus gauges and sync-transition events.

Sources and limits

Upstream references and independent checks

Digest dated 2026-07-25 · upstream model claude-sonnet-4-6. Direct links are matched to all 1 upstream source IDs.

  1. 1
    Emit SyncedStatusReport only on sync status change (#2769)Direct upstream source · 5261a9defff464bf5c1504dfbe884be68cb21111

This Research brief was generated by Terra from a dated upstream research digest. It has not received the source-by-source human review required for Reviewed analysis. Material limit: This is a master-branch commit rather than a release, based on one approved upstream record; the record does not establish release timing or downstream adoption.