nips/05-metadata.md
2024-04-24 10:46:22 -04:00

5.2 KiB

NIP-05 Metadata

Adding Metadata to DNS-based internet identifiers

draft optional

This NIP proposes the addtion of "metadata to the nip-05 response to provide metadata about the identifier.

Consistent with NIP-05 a client will make a GET request to https://example.com/.well-known/nostr.json?name=bob and get back a response that will have the additional key of "metadata" mapped to a list of metadata items.

Each metadata item has

  • One MANDATORY item of JSON stringified metadata consistent with kind 0
  • A second OPTIONAL item of which is a JSON signature of the first MANDATORY item. The pubkey for verifying this signature is the pubkey corresponding to the name parameter
  • A third OPTIONAL item may exist, if the pubkey used to verify the signature is other than the name.
{
  "names": {
    "bob": "b0635d6a9851d3aed0cd6c495b282167acf761729078d975fc341b22650b07b9"
  }
}

or with the recommended "relays" attribute:

{
  "names": {
    "bob": "b0635d6a9851d3aed0cd6c495b282167acf761729078d975fc341b22650b07b9"
  },
  "relays": {
    "b0635d6a9851d3aed0cd6c495b282167acf761729078d975fc341b22650b07b9": [ "wss://relay.example.com", "wss://relay2.example.com" ]
  },
  "metadata": []
}

If the pubkey matches the one given in "names" (as in the example above) that means the association is right and the "nip05" identifier is valid and can be displayed.

The recommended "relays" attribute may contain an object with public keys as properties and arrays of relay URLs as values. When present, that can be used to help clients learn in which relays the specific user may be found. Web servers which serve /.well-known/nostr.json files dynamically based on the query string SHOULD also serve the relays data for any name they serve in the same reply when that is available.

Finding users from their NIP-05 identifier

A client may implement support for finding users' public keys from internet identifiers, the flow is the same as above, but reversed: first the client fetches the well-known URL and from there it gets the public key of the user, then it tries to fetch the kind 0 event for that user and check if it has a matching "nip05".

Notes

Clients must always follow public keys, not NIP-05 addresses

For example, if after finding that bob@bob.com has the public key abc...def, the user clicks a button to follow that profile, the client must keep a primary reference to abc...def, not bob@bob.com. If, for any reason, the address https://bob.com/.well-known/nostr.json?name=bob starts returning the public key 1d2...e3f at any time in the future, the client must not replace abc...def in his list of followed profiles for the user (but it should stop displaying "bob@bob.com" for that user, as that will have become an invalid "nip05" property).

Public keys must be in hex format

Keys must be returned in hex format. Keys in NIP-19 npub format are only meant to be used for display in client UIs, not in this NIP.

User Discovery implementation suggestion

A client can also use this to allow users to search other profiles. If a client has a search box or something like that, a user may be able to type "bob@example.com" there and the client would recognize that and do the proper queries to obtain a pubkey and suggest that to the user.

Showing just the domain as an identifier

Clients may treat the identifier _@domain as the "root" identifier, and choose to display it as just the <domain>. For example, if Bob owns bob.com, he may not want an identifier like bob@bob.com as that is redundant. Instead, Bob can use the identifier _@bob.com and expect Nostr clients to show and treat that as just bob.com for all purposes.

Reasoning for the /.well-known/nostr.json?name=<local-part> format

By adding the <local-part> as a query string instead of as part of the path, the protocol can support both dynamic servers that can generate JSON on-demand and static servers with a JSON file in it that may contain multiple names.

Allowing access from JavaScript apps

JavaScript Nostr apps may be restricted by browser CORS policies that prevent them from accessing /.well-known/nostr.json on the user's domain. When CORS prevents JS from loading a resource, the JS program sees it as a network failure identical to the resource not existing, so it is not possible for a pure-JS app to tell the user for certain that the failure was caused by a CORS issue. JS Nostr apps that see network failures requesting /.well-known/nostr.json files may want to recommend to users that they check the CORS policy of their servers, e.g.:

$ curl -sI https://example.com/.well-known/nostr.json?name=bob | grep -i ^Access-Control
Access-Control-Allow-Origin: *

Users should ensure that their /.well-known/nostr.json is served with the HTTP header Access-Control-Allow-Origin: * to ensure it can be validated by pure JS apps running in modern browsers.

Security Constraints

The /.well-known/nostr.json endpoint MUST NOT return any HTTP redirects.

Fetchers MUST ignore any HTTP redirects given by the /.well-known/nostr.json endpoint.