Nostr NIPS 85

Last Updated: 2026-02-18

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NIP-85

Trusted Assertions

draft optional

Certain Webs of Trust calculations require access to a large volume of events and/or computing power, making it virtually impossible to perform them directly on clients. This NIP allows users to offload such calculations to declared trusted service providers, and for these providers to publish signed “Trusted Assertion” events for the user client’s consumption.

Assertion Events

Trusted Assertions are always addressable (replaceable) events with the d tag pointing to the “subject” of the assertion. This NIP currently recognizes four distinct target “subjects” on which such calculations can be performed: pubkeys, regular events, addressable events, and nip73 identifiers. Each subject type is mapped to an event kind:

Subject	Event Kind	`d` tag value
User	30382	`<pubkey>`
Event	30383	`<event_id>`
Addressable Event	30384	`<event_address>`
NIP-73 Identifier	30385	`<i-tag>`

Calculation results are saved in pre-defined tags whose syntax and semantics are agreed upon by providers and clients.

Example of ranking a pubkey with a web of trust score of 89:

{
  "kind": 30382,
  "pubkey": "<service pubkey>",
  "tags": [
    ["d", "e88a691e98d9987c964521dff60025f60700378a4879180dcbbb4a5027850411"], // target user's public key
    ["rank", "89"],
  ],
  "content": "",
  //...
}

Service providers MUST use different service keys for distinct algorithms, including a key per user when the algorithm is personalized to that user’s point of view or settings.

Kind 30382: Users as Subject:

The following result types have been declared:

Result type	Tag name	Tag value format
Follower Count	`followers`	int
User Rank	`rank`	int, norm 0-100
First Post Time	`first_created_at`	unix timestamp
Post Count	`post_cnt`	int
Reply Count	`reply_cnt`	int
Reactions Count	`reactions_cnt`	int
Zap Amount Received	`zap_amt_recd`	int, sats
Zap Amount Sent	`zap_amt_sent`	int, sats
Zap Number Received	`zap_cnt_recd`	int
Zap Number Sent	`zap_cnt_sent`	int
Avg Zap Amount/day recd	`zap_avg_amt_day_recd`	int, sats
Avg Zap Amount/day sent	`zap_avg_amt_day_sent`	int, sats
Reports Received	`reports_cnt_recd`	int
Reports Sent	`reports_cnt_sent`	int
Common Topics	`t`	string
Generally active start	`active_hours_start`	int, 0-24, UTC
Generally active end	`active_hours_end`	int, 0-24, UTC

Each provider can offer their own ways to calculate such values. For instance, the Follower Count of one trust provider might remove the user’s muted public keys while another provider keeps them. Users can then choose how they want to see this information in their preferred client by picking a provider that aligns with their view.

Kind 30383: Events as Subject

Providers can rate individual events with the following tags:

Result type	Tag name	Tag value format
Event Rank	`rank`	int, norm 0-100
Event Comment Count	`comment_cnt`	int
Event Quote Count	`quote_cnt`	int
Event Repost Count	`repost_cnt`	int
Event Reaction Count	`reaction_cnt`	int
Event Zap Count	`zap_cnt`	int
Event Zap Amount	`zap_amount`	int, sats

Kind 30384: Addressables as Subject

Providers can rate all versions of addressable events using the following tags:

Result type	Tag name	Tag value format
Address Rank	`rank`	int, norm 0-100
Address Comment Count	`comment_cnt`	int
Address Quote Count	`quote_cnt`	int
Address Repost Count	`repost_cnt`	int
Address Reaction Count	`reaction_cnt`	int
Address Zap Count	`zap_cnt`	int
Address Zap Amount	`zap_amount`	int, sats

Kind 30385: External identifier as Subject

Providers can rate books, locations, movies, websites, and hashtags using NIP-73 identifiers.

Result type	Tag name	Tag value format
Rank	`rank`	int, norm 0-100
Comment Count	`comment_cnt`	int
Reaction Count	`reaction_cnt`	int

NIP-73 k tags should be added to the event as well.

Declaring Trusted Service Providers

Kind 10040 lists the user’s authorized providers for each result. Each kind:tag is followed by the pubkey of the service and the relay where the results are published. Users can specify these publicly or privately by JSON-stringifying and encrypting the tag list in the .content using NIP-44.

{
  "kind": 10040,
  "tags": [
    ["<kind:tag>", "<service key>", "<relay hint>"],

    // examples
    ["30382:rank", "4fd5e210530e4f6b2cb083795834bfe5108324f1ed9f00ab73b9e8fcfe5f12fe", "wss://nip85.nostr.band"],
    ["30382:rank", "3d842afecd5e293f28b6627933704a3fb8ce153aa91d790ab11f6a752d44a42d", "wss://nostr.wine"],
    ["30382:zap_amt_sent", "4fd5e210530e4f6b2cb083795834bfe5108324f1ed9f00ab73b9e8fcfe5f12fe", "wss://nip85.nostr.band"],
  ],
  "content": nip44Encrypt(JSON.stringify([
    ["<kind:tag>", "<service key>", "<relay hint>"],

     // examples
    ["30383:rank", "4fd5e210530e4f6b2cb083795834bfe5108324f1ed9f00ab73b9e8fcfe5f12fe", "wss://nip85.nostr.band"],
    ["30384:rank", "4fd5e210530e4f6b2cb083795834bfe5108324f1ed9f00ab73b9e8fcfe5f12fe", "wss://nip85.nostr.band"],
  ]),
  //...
}

If the provider offers several algorithms or multiple points of view of an algorithm, the key listed in each tag SHOULD point to the key created for each algorithm or point of view.

Final Considerations

Service providers SHOULD update Trusted Assertions as fast as new information arrives, but only if the contents of each event actually change to avoid re-downloading the same information.

Service providers MAY limit access to the results by using paid relays.

In TAs, p, e, and a tags with the same value as the d tag MAY be used to add a relay hint to the home relay of that user or event.

Appendix 1: Service provider discoverability

Service Providers SHOULD sign a kind 0 of each service key that explains who controls the key and what the current version of the algorithm is about.

{
  "kind": 0,
  "pubkey": "<service pubkey>",
  "tags": [],
  "content": "{
   \"name\" = \"Vitor's Brainstormer\", 
   \"about\" = \"A Web of Trust algorithm from Vitor's point of view that considers Follows and Mutes, but no reports, and gives extra score points for anyone around Boston\",
   \"picture\" = \"https://brainstorm.com/logo.png\",
   \"website\" = \"https://brainstorm.com\"
  }",
  // other fields...
}

Clients wishing to offer a list of Service Providers to their users SHOULD:

Download kind 10040 events of the user’s follow list
Connect to each of the listed relays and download the kind 0 of the respective service keys
Parse the kind 0 and collect the website property
Load the OpenGraph tags of that website and display them as clickable items

Source: nostr-protocol/nips/85.md version: 6df3a21 2026-02-17T05:41:06-05:00