Count

Functions for asking relays how many events match some filters, using NIP-45 COUNT.

Functions

countOne(options)

Asks one relay for a count. Resolves to the relay's answer, or undefined when the relay does not answer, which is a different result from 0.

Options:

• relay - Relay URL
• filters - Array of Nostr filters, sent in one COUNT message
• signal? - AbortSignal for cancellation
• context? - Adapter context

Support is read off the wire rather than from NIP-11. A relay that refuses with CLOSED, or stays silent for COUNT_TIMEOUT (3000 ms) while connected and authenticated, is remembered as unsupported for the session and not asked again. A CLOSED with an auth-required: or rate-limited: reason, a dropped connection, or an abort resolves to undefined without that verdict.

LOCAL_RELAY_URL answers from the repository.

count(options)

Asks several relays in parallel and resolves to the highest answer, or undefined if none answered. Relays hold overlapping subsets of the network, so the result is a lower bound.

Options:

• relays - Array of relay URLs
• All other options from countOne

supportsCount(relay)

true or false once the relay has answered or refused a COUNT, and undefined before.

Example

import {count} from "@welshman/net"

const total = await count({
  relays: ["wss://relay1.com", "wss://relay2.com"],
  filters: [{kinds: [7], "#e": [eventId]}],
  context,
})

if (total !== undefined) {
  console.log(`At least ${total} reactions`)
}