Snapshots of Replaceable Events

Snapshots of Replaceable Events

draft optional

Kind 1349 preserves one version of a replaceable or addressable event by wrapping it in a regular event, which relays keep.

Motivation

Relays keep only the latest replaceable or addressable event, so an author can rewrite a document and leave no trace of what it said before. Approvals and highlights point at a coordinate rather than at an id, so they silently transfer to whatever replaces the text they were given to.

The event

content is the wrapped event, serialized as JSON exactly as it appeared on the wire. Anyone may publish a snapshot: the inner signature proves who wrote the document, the outer one proves only who archived it.

{
  "kind": 1349,
  "content": "{\"id\":\"a1b2...\",\"pubkey\":\"9f8e...\",\"created_at\":1771547830,\"kind\":30817,\"tags\":[[\"d\",\"my-spec\"]],\"content\":\"# My Spec\",\"sig\":\"c3d4...\"}",
  "tags": [
    ["e", "a1b2..."],
    ["k", "30817"],
    ["p", "9f8e..."],
    ["a", "30817:9f8e...:my-spec"]
  ]
}

Validation

The tags are written by the publisher, who may be anyone. Without checking them, anyone could attach arbitrary events to another document's history.

Clients MUST discard a snapshot unless:

1. content parses as an event and its signature verifies;
2. e, k, p and a agree with the wrapped event;
3. the wrapped kind is replaceable or addressable.

Order versions by the wrapped event's created_at, not the snapshot's, which is only the time of archival. Deduplicate on the wrapped event's id; several archivers wrapping the same version is expected.

Querying

{ "kinds": [1349], "#a": ["30817:<pubkey>:<d>"] }

A snapshot proves a version existed. It never proves a set of them is complete, so a history is what was observed, not what happened.