Nostr Relay Framework -- use it to implement your own custom relay.

There is an example/reference implementation at basic. Binaries for that are also available under Releases.

Supported NIPs

These are handled by the framework itself, so every relay built on it gets them:

NIP
01	Basic protocol flow (EVENT, REQ, CLOSE, EOSE, OK, CLOSED, NOTICE), including what used to be NIPs 12, 15, 16, 20 and 33
09	Event deletion request
11	Relay information document
67	EOSE completeness hint
77	Negentropy syncing (NEG-OPEN, NEG-MSG, NEG-CLOSE)

These depend on what your relay implements:

NIP	requires
42	Auther — authentication of clients to relays
17, 59	Auther — gift-wrapped events are only served to the pubkey they are addressed to
45	a storage implementing EventCounter — COUNT

The default NIP-11 document reports exactly this set. A relay implementing Informationer replaces the document wholesale and is responsible for its own supported_nips.

Note that the numbers 12, 15, 16, 20 and 33 still appear in that document for the benefit of older clients; those NIPs were merged into NIP-01 and no longer exist on their own.

Running several instances on one storage

Live subscriptions are tracked in memory, so out of the box an event published to one instance is only pushed to the clients of that instance. To run several instances (behind a load balancer, say) against one shared storage, implement Notifier on your relay or on your storage:

type Notifier interface {
	Notify(context.Context, *nostr.Event) error
	Notifications(context.Context) (<-chan *nostr.Event, error)
}

Notify is called for every accepted event; Notifications must deliver the events accepted by every instance, this one included. With a Notifier present, events reach local subscribers only through Notifications, so there is a single delivery path and no duplicates.

Notifier is eventstore.Notifier, and the postgresql storage implements it with LISTEN/NOTIFY, so a relay on PostgreSQL gets this for free. For any other storage the transport is up to you — Redis pub/sub, NATS, anything that carries events from Notify on one instance to Notifications on all of them; see multi-instance for SQLite kept in sync over Redis.