Nip85 Stats

NIP-85 Trusted Assertion Stats

NIP-85 defines "Trusted Assertions" — events published by a service provider that carry pre-computed stats (follower counts, reaction counts, zap totals, etc.) for users and events. Clients that would otherwise need to load thousands of events to compute these numbers can instead query a single addressable event from a trusted provider.

This skill adds three hooks — useNip85UserStats, useNip85EventStats, useNip85AddrStats — and a configurable nip85StatsPubkey field on AppConfig so you can swap providers.

Kinds Used

The hooks query one replaceable event at a time (limit: 1), filtered by authors: [statsPubkey] and #d. Filtering by authors is required — without it, anyone could publish a fake assertion with the same d tag and the client would accept it.

Files Provided by This Skill

Setup Instructions

1. Copy the Hooks File

Copy .agents/skills/nip85-stats/files/hooks/useNip85Stats.ts into src/hooks/useNip85Stats.ts. It imports @nostrify/react, @tanstack/react-query, and @/hooks/useAppContext, all already present in the template.

2. Add nip85StatsPubkey to AppConfig

In src/contexts/AppContext.ts, add the field to the AppConfig interface:

export interface AppConfig {
  // ...existing fields...
  /** Hex pubkey of the NIP-85 Trusted Assertion provider. Empty = disabled. */
  nip85StatsPubkey: string;
}

3. Update the Zod Schema in AppProvider.tsx

In src/components/AppProvider.tsx, add the field to AppConfigSchema:

const AppConfigSchema = z.object({
  // ...existing fields...
  nip85StatsPubkey: z.string().refine(
    (val) => val.length === 0 || /^[0-9a-f]{64}$/i.test(val),
    { message: 'Must be empty or a 64-character hex pubkey' },
  ),
}) satisfies z.ZodType<AppConfig>;

4. Set the Default in App.tsx

Pick a provider pubkey and add it to defaultConfig. The ditto.pub provider is a reasonable default:

const defaultConfig: AppConfig = {
  // ...existing fields...
  nip85StatsPubkey: '5f68e85ee174102ca8978eef302129f081f03456c884185d5ec1c1224ab633ea',
};

Set to '' to ship with stats disabled.

5. Update TestApp.tsx

In src/test/TestApp.tsx, add the field to the test default config. Use an empty string so tests don't hit a live provider:

const defaultConfig: AppConfig = {
  // ...existing fields...
  nip85StatsPubkey: '',
};

Usage

User stats (kind 30382)

import { useNip85UserStats } from '@/hooks/useNip85Stats';

function FollowerCount({ pubkey }: { pubkey: string }) {
  const { data: stats } = useNip85UserStats(pubkey);
  if (!stats) return null; // no provider configured or no assertion yet
  return <span>{stats.followers.toLocaleString()} followers</span>;
}

Event stats (kind 30383)

import { useNip85EventStats } from '@/hooks/useNip85Stats';

function NoteStats({ eventId }: { eventId: string }) {
  const { data: stats } = useNip85EventStats(eventId);
  if (!stats) return null;
  return (
    <div className="flex gap-3 text-sm text-muted-foreground">
      <span>{stats.reactionCount} reactions</span>
      <span>{stats.repostCount} reposts</span>
      <span>{stats.commentCount} comments</span>
      <span>{stats.zapAmount} sats</span>
    </div>
  );
}

Addressable event stats (kind 30384)

The addr argument is the full NIP-01 event address <kind>:<pubkey>:<d-tag>:

import { useNip85AddrStats } from '@/hooks/useNip85Stats';

function ArticleStats({ kind, pubkey, identifier }: { kind: number; pubkey: string; identifier: string }) {
  const { data: stats } = useNip85AddrStats(`${kind}:${pubkey}:${identifier}`);
  if (!stats) return null;
  return <span>{stats.reactionCount} reactions</span>;
}

Behavior Notes

• Graceful degradation: The hooks return null (not an error) when nip85StatsPubkey is empty or the provider has no assertion for the subject. Always render defensively — NIP-85 is an optimization, not a source of truth.
• Short timeouts: Each query is wrapped in a 2-second AbortSignal.timeout so a slow stats relay never blocks the UI.
• Cached by TanStack Query: staleTime is 30s for event/addr stats and 60s for user stats. Results are keyed on [kind, subject, statsPubkey], so swapping providers invalidates the cache automatically.
• Missing tags = 0: A tag absent from the assertion is reported as 0 rather than undefined, matching NIP-85's "no data" semantics.
• Not the source of truth: For interactive features (did this user like this post?) you still need to query the underlying reaction/zap/repost events. NIP-85 only provides aggregate counts.

Extending the Stats

The hooks expose a small subset of the tags defined in NIP-85. To surface more (e.g. zap_amt_sent, rank, first_created_at), extend the return types and pull additional tags via getIntTag:

export interface Nip85UserStats {
  followers: number;
  postCount: number;
  rank: number;            // new
  zapAmtReceived: number;  // new
}

// inside useNip85UserStats queryFn
return {
  followers: getIntTag(tags, 'followers'),
  postCount: getIntTag(tags, 'post_cnt'),
  rank: getIntTag(tags, 'rank'),
  zapAmtReceived: getIntTag(tags, 'zap_amt_recd'),
};

See the full tag table in NIP-85.

Exposing a Provider Picker (Optional)

If you want the user to change providers at runtime, add an input bound to config.nip85StatsPubkey and call updateConfig with a validated 64-char hex value:

import { useAppContext } from '@/hooks/useAppContext';

function StatsProviderInput() {
  const { config, updateConfig } = useAppContext();
  return (
    <input
      value={config.nip85StatsPubkey}
      => {
        const v = e.target.value.trim().toLowerCase();
        if (v === '' || /^[0-9a-f]{64}$/.test(v)) {
          updateConfig(() => ({ nip85StatsPubkey: v }));
        }
      }}
      placeholder="64-char hex pubkey (blank to disable)"
    />
  );
}

Related NIPs

• NIP-85 — Trusted Assertions (this skill)
• NIP-01 — Addressable event addressing (<kind>:<pubkey>:<d-tag>)
• NIP-57 — Zaps (the underlying events zap_amount / zap_cnt aggregate)