Relay Monitoring

Relay monitors are services that check relays and publish what they find (NIP-66). A monitor announces itself with a kind 10166 event, then publishes an addressable kind 30166 discovery event per relay, keyed by the relay URL, with its latency, supported NIPs, and requirements.

Finding monitors

Cast monitor announcements with RelayMonitor to read how often a monitor publishes and what it checks.

const monitors = use$(
  () => store.timeline({ kinds: [RELAY_MONITOR_ANNOUNCEMENT_KIND] }).pipe(castTimelineStream(RelayMonitor, store)),
  [],
);

monitor.frequency; // seconds between reports
monitor.checks; // ["open", "read", "write", ...]
monitor.timeouts; // [{ test?: "open", timeout: 5000 }]
monitor.geohash;

Checking a relay

monitor.relayStatus(url) returns an observable of the monitor's report for one relay, requested from the monitor's outboxes. The URL must match the report's d tag exactly, so normalize it with normalizeURL() first.

const status = use$(() => monitor.relayStatus(normalizeURL(url)), [monitor, url]);

Reading a report

The RelayDiscovery cast reads a kind 30166 report. Load every report from a monitor with a { kinds: [RELAY_DISCOVERY_KIND], authors: [pubkey] } filter.

report.url; // the relay from the "d" tag
report.rttOpen; // ms to connect; also rttRead and rttWrite
report.networkType; // "clearnet", "tor", "i2p", or "loki"
report.supportedNIPs; // ["1", "11", "42"]
report.requirements; // ["auth", "!payment"]
report.acceptedKinds; // ["1", "!4"]

types, attributes, topics, geohash, and geohashes read the remaining tags. Values prefixed with ! mean the opposite, such as no payment required.

Helpers

• isValidRelayMonitorAnnouncement(event) and isValidRelayDiscovery(event) validate the two kinds; a report needs a d tag
• getMonitorFrequency, getMonitorTimeouts, getMonitorChecks, and getMonitorGeohash read announcements
• getRelayDiscoveryRTT(event, "open" | "read" | "write") and the other getRelayDiscovery* helpers read reports
• RELAY_MONITOR_ANNOUNCEMENT_KIND and RELAY_DISCOVERY_KIND are the kind numbers

Examples: Monitor feed · Relay directory

Best Practices

• Filter reports with since a few multiples of monitor.frequency to skip relays the monitor stopped checking
• Combine reports from several monitors before ranking relays, since each sees the network from one place
• Request reports from the monitor's outboxes, as relayStatus() does