nips/02.md

3.4 KiB

NIP-02

Follow List

final optional

Three special events having kinds 3, 10, and 11 are defined as having a list of p tags. Kind 3 defines the complete set of pubkeys one is following at a given point in time; kind 10 adds one or more pubkeys to that list; and kind 11 removes one or more pubkeys from that list.

Each tag entry should contain the key for the profile, a relay URL where events from that key can be found (can be set to an empty string if not needed), and a local name (or "petname") for that profile (can also be set to an empty string or not provided), i.e., ["p", <32-bytes hex key>, <main relay URL>, <petname>]. The content can be anything and should be ignored.

For example:

{
  "kind": 3,
  "tags": [
    ["p", "91cf9..4e5ca", "wss://alicerelay.com/", "alice"],
    ["p", "14aeb..8dad4", "wss://bobrelay.com/nostr", "bob"],
    ["p", "612ae..e610f", "ws://carolrelay.com/ws", "carol"]
  ],
  "content": "",
  ...other fields
}

Every new following list that gets published overwrites the past ones, so it should contain all entries. Relays and clients SHOULD delete past following lists as soon as they receive a new one.

Whenever new follows are added to an existing list, clients SHOULD append them to the end of the list, so they are stored in chronological order.

When building a contact list, clients should query for the latest kind 3 event, and any subsequent kind 10 and 11 events that modify the original list. Contacts SHOULD use kind 10 and 11 in order to prevent race conditions when updating contact lists from multiple clients simultaneously, unless the intention is to write a canonical, complete contact list.

Uses

Follow list backup

If one believes a relay will store their events for sufficient time, they can use this kind-3 event to backup their following list and recover on a different device.

Profile discovery and context augmentation

A client may rely on the kind-3 event to display a list of followed people by profiles one is browsing; make lists of suggestions on who to follow based on the follow lists of other people one might be following or browsing; or show the data in other contexts.

Relay sharing

A client may publish a follow list with good relays for each of their follows so other clients may use these to update their internal relay lists if needed, increasing censorship-resistance.

Petname scheme

The data from these follow lists can be used by clients to construct local "petname" tables derived from other people's follow lists. This alleviates the need for global human-readable names. For example:

A user has an internal follow list that says

[
  ["p", "21df6d143fb96c2ec9d63726bf9edc71", "", "erin"]
]

And receives two follow lists, one from 21df6d143fb96c2ec9d63726bf9edc71 that says

[
  ["p", "a8bb3d884d5d90b413d9891fe4c4e46d", "", "david"]
]

and another from a8bb3d884d5d90b413d9891fe4c4e46d that says

[
  ["p", "f57f54057d2a7af0efecc8b0b66f5708", "", "frank"]
]

When the user sees 21df6d143fb96c2ec9d63726bf9edc71 the client can show erin instead; When the user sees a8bb3d884d5d90b413d9891fe4c4e46d the client can show david.erin instead; When the user sees f57f54057d2a7af0efecc8b0b66f5708 the client can show frank.david.erin instead.