Video Events

1 Overview

A video event is a dedicated post about one externally hosted video. The event does not carry the video bytes. It carries every piece of metadata a player needs: URLs, formats, resolutions, previews, audio tracks, and chapters.

A NIP-01 kind:1 note can also link a video. The difference is intent. A kind-1 note targets micro-blogging clients. A video event targets video-specific clients, in the style of Netflix, YouTube, or TikTok. There the video is the center of the experience, and clients need structured metadata, not a bare link.

This NIP defines four kinds. Kinds 21 and 22 are regular events for normal and short videos. Kinds 34235 and 34236 are addressable versions of the same two formats. The media metadata itself rides in imeta tags from NIP-92.

2 The Four Video Kinds

There are two types of video events: normal and short. Normal videos are longer and mostly horizontal (landscape). Short videos are short-form and mostly vertical (portrait): "stories", "reels", "shorts". The split lets a client build a different viewing experience for each type.

The split is stylistic, not technical. Nothing except common sense stops a short video from being long, or a normal video from being vertical. The kind states how the author wants the video presented. It does not constrain the raw size or dimensions.

In every one of the four kinds, the content field holds a summary or description of the video. The primary source of video information is the imeta tags, described in §4.

3 Addressable Video Events

Some video posts need edits after publication. Kinds 34235 and 34236 exist for that case. They follow the same format as kinds 21 and 22. They add one required tag: a d tag with a unique, user-chosen identifier string. Publish a new event with the same d value to update the post. The addressable reference stays stable across updates.

Use the addressable kinds for:

• Metadata corrections — fix descriptions, titles, or tags without republishing the video.
• Preservation of imported content IDs from legacy platforms.
• URL migration when the hosting server changes.
• Platform migration tracking.

Referencing an addressable video

Reference an addressable video with a standard NIP-01 a tag:

["a", "34235:<pubkey>:<d-tag-value>", "<relay-url>"]  // normal videos
["a", "34236:<pubkey>:<d-tag-value>", "<relay-url>"]  // short videos

4 Video Data: imeta Tags

Each imeta tag describes one file. One video event can carry many imeta tags. Each tag can specify one variant of the video, distinguished by the dim (dimensions) and m (MIME type) properties. Extra imeta tags can carry separate audio tracks, one per language.

Clients should check if separate audio tracks are available and prefer them over in-video audio. Separate audio allows smooth resolution switching without interrupting the sound. The ov flag on the l (language) property marks the original language track.

This NIP defines three additional imeta properties, on top of those listed in NIP-92 and NIP-94:

[
  ["imeta",
    "dim 1920x1080",
    "url https://myvideo.com/1080/12345.mp4",
    "x 3093509d1e0bc604ff60cb9286f4cd7c781553bc8991937befaacfdc28ec5cdc",
    "m video/mp4",
    "image https://myvideo.com/1080/12345.jpg",
    "image https://myotherserver.com/1080/12345.jpg",
    "fallback https://myotherserver.com/1080/12345.mp4",
    "fallback https://andanotherserver.com/1080/12345.mp4",
    "service nip96",
    "bitrate 3000000",
    "duration 29.223"
  ],
  ["imeta",
    "dim 1280x720",
    "url https://myvideo.com/720/12345.mp4",
    "x e1d4f808dae475ed32fb23ce52ef8ac82e3cc760702fca10d62d382d2da3697d",
    "m video/mp4",
    "image https://myvideo.com/720/12345.jpg",
    "fallback https://myotherserver.com/720/12345.mp4",
    "service nip96",
    "bitrate 2000000",
    "duration 29.24"
  ],
  ["imeta",
    "dim 1280x720",
    "url https://myvideo.com/720/12345.m3u8",
    "x 704e720af2697f5d6a198ad377789d462054b6e8d790f8a3903afbc1e044014f",
    "m application/x-mpegURL",
    "image https://myvideo.com/720/12345.jpg",
    "fallback https://myotherserver.com/720/12345.m3u8",
    "service nip96",
    "duration 29.21"
  ],
  ["imeta",
    "url https://myaudio.com/audio/en/12345.mp3",
    "x b2e0a7a82ac9f3f3a71f1d9a78c381d5be9d1cf19dce258765c17c8a76287c93",
    "m audio/mp3",
    "waveform 0 7 35 8 100 100 49 8 4 16 8 10 7 2 20 10 100 100 ...",
    "l en ISO-639-1 ov",
    "fallback https://myotherserver.com/audio/en/12345.mp3",
    "service nip96",
    "bitrate 320000",
    "duration 29.24"
  ]
]

5 Tag Reference

Outside the imeta tags, a video event uses the tags below. The title tag is required on every video event. The d tag is required on the addressable kinds only.

6 Worked Example

The event below is a complete short video, kind 22. It offers one mp4 file with a preview image, one fallback server, a caption track, one participant, and hashtags.

{
  "id": "7fdc7e6a15…",
  "pubkey": "22a12a12…",
  "created_at": 1749762600,
  "kind": 22,
  "content": "My cat discovers the water tap. 29 seconds of chaos.",
  "tags": [
    ["title", "Cat vs. tap"],
    ["published_at", "1749762600"],
    ["alt", "A vertical phone video of a cat pawing at a running tap"],
    ["imeta",
      "dim 1080x1920",
      "url https://myvideo.com/v/cat-tap.mp4",
      "x 3093509d1e0bc604ff60cb9286f4cd7c781553bc8991937befaacfdc28ec5cdc",
      "m video/mp4",
      "image https://myvideo.com/v/cat-tap.jpg",
      "fallback https://myotherserver.com/v/cat-tap.mp4",
      "service nip96",
      "bitrate 2500000",
      "duration 29.223"
    ],
    ["text-track", "https://myvideo.com/v/cat-tap.en.vtt", "captions", "en"],
    ["segment", "00:00:00.000", "00:00:12.000", "The approach", "https://myvideo.com/v/seg1.jpg"],
    ["segment", "00:00:12.000", "00:00:29.223", "Contact", "https://myvideo.com/v/seg2.jpg"],
    ["content-warning", "mild cat distress"],
    ["p", "f7234bd4c139…76e9ca", "wss://relay.example.com"],
    ["t", "cats"],
    ["t", "shorts"],
    ["r", "https://myblog.example.com/cat-tap"]
  ],
  "sig": "e8551d85…"
}

An imported catalog uses the addressable kinds instead. The event below is kind 34235. The d tag preserves the legacy platform ID, and the origin tag records where the video came from. Republishing with the same d value updates the metadata in place.

{
  "kind": 34235,
  "content": "Full 40-minute talk on relay economics.",
  "tags": [
    ["d", "yt-dQw4w9WgXcQ"],
    ["title", "Relay Economics 101"],
    ["published_at", "1702166400"],
    ["imeta",
      "url https://example.com/talks/relay-econ.mp4",
      "m video/mp4",
      "dim 1920x1080",
      "blurhash eVF$^OI:${M{%LRjWBoLoLaeR*",
      "image https://example.com/talks/relay-econ.jpg",
      "x 3093509d1e0bc604ff60cb9286f4cd7c781553bc8991937befaacfdc28ec5cdc",
      "duration 2400.0"
    ],
    ["origin", "youtube", "dQw4w9WgXcQ", "https://youtube.com/watch?v=dQw4w9WgXcQ"]
  ],
  … id / pubkey / created_at / sig as usual …
}
-- reference it from any other event --
["a", "34235:22a12a12…:yt-dQw4w9WgXcQ", "wss://relay.example.com"]

7 Version History

The spec started life as a proposal numbered 44 and became NIP-71 on merge. It has grown from a simple video post into a full playback-metadata format. Notable changes, newest first:

• 20262026-05Added multiple audio tracks per video: the l language property, the ov original-version flag, and the waveform property.
• 20262026-01Added the addressable kinds 34235 and 34236, the required d tag, and the origin tag for imported content.
• 20252025-10Added the duration and bitrate imeta properties.
• 20252025-01Made video events regular: the original addressable kinds 34235/34236 became kinds 21 and 22.
• 20242024-05Moved all file metadata into NIP-92 imeta tags; removed the aes-256-gcm tag.
• 2023-242023-12Early edits: removed the summary tag; renamed the proposal from 44 to 71.
• Origin2023-12zmeyer44 opened the first draft, "Create NIP 44 for Video Events".

8 See Also

• NIP-01 — the base event format, regular and addressable storage classes, and a tags.
• NIP-92 — defines the imeta tag this NIP builds on.
• NIP-94 — file metadata fields (url, m, x, dim, blurhash, …) reused inside imeta.
• NIP-96 — HTTP file storage; the target of service nip96 hash lookups.
• NIP-68 — picture-first feeds; the same idea for images instead of video.
• NIP-53 — live streaming events, for video that is still being broadcast.