Kind 2003: Torrent

Overview

Kind 2003 events represent torrents in the Nostr ecosystem. These events serve as a simple torrent index, providing enough information to search for content and construct magnet links without storing actual torrent files on Nostr. This allows for decentralized content indexing and discovery while maintaining the efficient peer-to-peer distribution mechanism of the BitTorrent protocol.

Specification

Property	Value
Kind Number	2003
Event Range	Ephemeral
Defined in	NIP-35

Content Format

The content field contains a long-form description of the torrent, which can be pre-formatted text providing details about the content.

Schema

"content": "Dune: Part Two (2024)\nDirector: Denis Villeneuve\n\nThe saga continues as Paul Atreides unites with Chani and the Fremen, seeking revenge against those who destroyed his family and plotting to prevent a terrible future only he can foresee."

Tags

Tag Name	Description	Format	Required
title	Torrent title	["title", "<torrent-title>"]	Yes
x	BitTorrent Info Hash	["x", "<bittorrent-info-hash>"]	Yes
file	File entry inside the torrent	["file", "<file-name>", "<file-size-in-bytes>"]	No
tracker	Tracker URL for the torrent	["tracker", "<tracker-url>"]	No
i	External identifier	["i", "<prefix>:<value>"]	No
t	General category tags	["t", "<category>"]	Recommended

Identity Tags

The i tag can include various prefixes for external identifiers:

Prefix	Description	Example
tcat	Text category path	["i", "tcat:video,movie,4k"]
newznab	Newznab category ID	["i", "newznab:2045"]
imdb	IMDB ID	["i", "imdb:tt15239678"]
tmdb	The Movie Database ID	["i", "tmdb:movie:693134"]
ttvdb	TV Database ID	["i", "ttvdb:movie:290272"]
mal	MyAnimeList ID	["i", "mal:anime:9253"]
anilist	AniList ID	["i", "anilist:123456"]

Client Behavior

Clients should:

1. Display torrent information in a user-friendly manner with title and description
2. Generate magnet links using the BitTorrent Info Hash
3. List included files and their sizes when available
4. Show relevant external identifiers and provide links to those platforms when possible
5. Support searching and filtering by category tags
6. Optionally support directly launching torrents in compatible BitTorrent clients

Relay Behavior

Relays should:

1. Store and serve torrent events like other ephemeral events
2. Support filtering by tags to enable content discovery

Use Cases

• Creating decentralized content indexes
• Sharing media collections
• Distributing open-source software
• Archiving public domain content
• Building specialized torrent search engines on Nostr

Example

{
  "id": "4376c65d2f232afbe9b882a35baa4f6fe8667c4e684749af565f981833ed6a65",
  "pubkey": "79dff8f82963424e0bb02708a22e44b4980893e3a4be0fa3cb60a43b946764e3",
  "created_at": 1671217411,
  "kind": 2003,
  "tags": [
    ["title", "Dune: Part Two (2024) 4K UHD HDR REMUX BluRay"],
    ["x", "e9a66852501bfc88cd4773dc9fce35809fda167c"],
    ["file", "dune_part_two_2024_4k.mkv", "65432154321"],
    ["file", "sample.mp4", "54321543"],
    ["tracker", "udp://tracker.opentrackr.org:1337/announce"],
    ["tracker", "http://tracker.openbittorrent.com:80/announce"],
    ["i", "tcat:video,movie,4k"],
    ["i", "newznab:2045"],
    ["i", "imdb:tt15239678"],
    ["i", "tmdb:movie:693134"],
    ["t", "movie"],
    ["t", "4k"],
    ["t", "science fiction"]
  ],
  "content": "Dune: Part Two (2024)\nDirector: Denis Villeneuve\n\nThe saga continues as Paul Atreides unites with Chani and the Fremen, seeking revenge against those who destroyed his family and plotting to prevent a terrible future only he can foresee.",
  "sig": "908a15e46fb4d8675bab026fc230a0e3542bfade63da02d542fb78b2a8513fcd0092619a2c8c1221e581946e0191f2af505dfdf8657a414dbca329186f009262"
}

References

• NIP-35: Torrents
• BitTorrent Magnet URI Scheme

Related Kinds

• Kind 2004: Torrent Comment - Comments on torrents
• Kind 1: Short Text Note - For discussions about torrents
• Kind 1111: Comment - For structured comments on torrents

Notes

• No actual torrent files are stored on Nostr; only the metadata needed to find and download the content
• When constructing magnet links, use the format: magnet:?xt=urn:btih:HASH with optional tracker parameters
• Include descriptive category tags to make torrents more discoverable
• The file tag can be repeated for each file in the torrent
• External identifiers help link the content to recognized databases and improve searchability
• Implementers may wish to add content warnings or age verification for adult content