NIP-85 defines Trusted Assertions, a system for delegating expensive calculations to trusted service providers who publish signed results as Nostr events.

How It Works

Web of Trust scores, engagement metrics, and other computed values require crawling many relays and processing large event volumes. This work is impractical on mobile devices. NIP-85 lets specialized providers perform these calculations and publish results that clients can query.

Trusted Assertions are addressable events. The d tag identifies the subject being scored, and the event kind identifies what sort of subject it is: pubkeys (30382), regular events (30383), addressable events (30384), and NIP-73 identifiers (30385).

Users declare which providers they trust through kind 10040. Those provider lists can be public in tags or encrypted in the event content with NIP-44, which matters when a user does not want to publish their trust inputs openly.

Why It Matters

The useful insight in NIP-85 is that it standardizes outputs, not algorithms. Two providers can both publish a rank tag for the same pubkey while using different Web of Trust formulas, mute handling, relay coverage, or anti-spam heuristics. Clients stay interoperable because the result format matches even when the computation does not.

That is a better fit for Nostr than pretending there will be one canonical ranking service. Users choose whose assertions they trust.

Trust Model

Service providers must sign their own assertion events, and the spec recommends different service keys for different algorithms or user-specific viewpoints. That keeps a provider from collapsing unrelated ranking systems into one opaque identity.

Trust still stays local. Signed output proves which provider published a score, not that the score is correct. Clients need policy around which provider keys to use, which relays to fetch from, and how to handle conflicting assertions.

Interop Notes

NIP-85 extends beyond people and posts. Kind 30385 lets providers score NIP-73 external identifiers such as books, websites, hashtags, and locations. That creates a path for interoperable reputation and engagement data around subjects outside Nostr itself.

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