NIP-73

External Content IDs

draft optional

There are certain established global content identifiers that would be useful to reference in nostr events so that clients can query all events assosiated with these ids.

• Book ISBNs
• Podcast GUIDs
• Movie ISANs

Since the i tag is already used for similar references in kind-0 metadata events it makes sense to use it for these content ids as well.

Supported IDs

Books:

• Book ISBN: ["i", "isbn:9780765382030"] - https://isbnsearch.org/isbn/9780765382030

Book ISBNs MUST be referenced without hyphens as many book search APIs return the ISBNs without hyphens. Removing hypens from ISBNs is trivial, whereas adding the hyphens back in is non-trivial requiring a library.

Podcasts:

• Podcast RSS Feed GUID: ["i", "podcast:guid:c90e609a-df1e-596a-bd5e-57bcc8aad6cc"] - https://podcastindex.org/podcast/c90e609a-df1e-596a-bd5e-57bcc8aad6cc
• Podcast RSS Item GUID: ["i", "podcast:item:guid:d98d189b-dc7b-45b1-8720-d4b98690f31f"]
• Podcast RSS Publisher GUID: ["i", "podcast:publisher:guid:18bcbf10-6701-4ffb-b255-bc057390d738"]

Movies:

• Movie ISAN: ["i", "isan:0000-0000-401A-0000-7"] - https://web.isan.org/public/en/isan/0000-0000-401A-0000-7

Movie ISANs SHOULD be referenced without the version part as the versions / edits of movies are not relevant. More info on ISAN parts here - https://support.isan.org/hc/en-us/articles/360002783131-Records-relations-and-hierarchies-in-the-ISAN-Registry

Optional URL Hints

Each i tag MAY have a url hint as the second argument to redirect people to a website if the client isn’t opinionated about how to interpret the id:

["i", "podcast:item:guid:d98d189b-dc7b-45b1-8720-d4b98690f31f", https://fountain.fm/episode/z1y9TMQRuqXl2awyrQxg]

["i", "isan:0000-0000-401A-0000-7", https://www.imdb.com/title/tt0120737]

Source: nostr-protocol/nips/73.md version: b4a2561 2024-09-02T20:33:45+03:30