NIP-66: Relay Monitoring

NIP-66 defines a standard for relay monitoring events. BigBrotr implements six health tests and optionally publishes the results as Nostr events.

Six Health Tests

The Nip66 class in bigbrotr.nips.nip66 runs independent health tests, each producing a specific MetadataType:

RTT (Round-Trip Time)

Opens a WebSocket connection to the relay and measures the round-trip time in milliseconds. This indicates the relay’s responsiveness.

MetadataType	`NIP66_RTT`
Measures	WebSocket handshake duration (ms)
Network support	All (clearnet, Tor, I2P, Lokinet)

SSL (Certificate Validation)

Inspects the relay’s SSL/TLS certificate for validity, expiration, and issuer information.

MetadataType	`NIP66_SSL`
Measures	Certificate validity, expiration date, issuer chain
Network support	Clearnet only (overlay networks use different transport)

DNS (Resolution)

Resolves the relay’s hostname and measures DNS resolution time.

MetadataType	`NIP66_DNS`
Measures	Resolution time, IP addresses, DNSSEC status
Network support	Clearnet only

Geo (Geographic Location)

Looks up the relay’s IP address in MaxMind GeoIP databases to determine geographic location.

MetadataType	`NIP66_GEO`
Measures	Country, city, ASN, latitude/longitude
Dependencies	MaxMind GeoLite2-City.mmdb

Net (Network Information)

Identifies the relay’s Autonomous System (AS) number, ISP, and network prefix.

MetadataType	`NIP66_NET`
Measures	AS number, ISP name, network prefix
Dependencies	MaxMind GeoLite2-ASN.mmdb

HTTP (Status Check)

Sends an HTTP request to the relay’s URL and records the response status, headers, and redirect chain.

MetadataType	`NIP66_HTTP`
Measures	HTTP status code, headers, redirects
Network support	All

Event Publishing

When the Monitor is configured with Nostr keys, it publishes monitoring results as Nostr events:

Kind 10166 — Replaceable Relay Monitor

A replaceable event containing the overall monitoring status for a relay. Each new publication replaces the previous one.

Kind 30166 — Parameterized Replaceable Relay Monitor

A parameterized replaceable event where the d tag identifies the relay. This enables clients to subscribe to monitoring data for specific relays.

Event Structure

{
  "kind": 30166,
  "tags": [
    ["d", "wss://relay.example.com"],
    ["rtt", "45"],
    ["ssl", "valid"],
    ["dns", "resolved"]
  ],
  "content": "",
  "created_at": 1700000000
}

Events are broadcast to configured relays using broadcast_events() from bigbrotr.utils.protocol.

Error Handling

Like NIP-11, all NIP-66 test methods never raise exceptions. Each test returns a result with logs.success indicating whether the test completed successfully. Failed tests produce no metadata — they are simply logged and skipped.

GeoIP Databases

The Geo and Net tests require MaxMind GeoLite2 databases:

GeoLite2-City.mmdb — for geographic location
GeoLite2-ASN.mmdb — for network/ASN information

These are managed by the GeoReaders mixin in services/common/mixins.py, which handles database file loading and lifecycle management. Database paths are configured in the Monitor’s YAML config.