nips/00.md

NIP-XX

Access Control Upgrade

draft optional

This NIP defines how to upgrade a public event with the property of limiting access to itself.

Upgrading a Public Event

A public event (with no access control), such as of kind:1, must be published or updated with a full_event tag pointing to a kind:40042 event address.

It's data should be set to a preview version of the full event. For example, a kind:1063 of an image file could set the url tag to a blurred version of the image, while a kind:1 event should set .content to a text excerpt of the full text such as "This is the first sentence of the full text. This text is trimmed...".

This guarantees backwards compatibility for clients not aware of this NIP.

Example:

{
  "kind": 1063,
  "tags": [
    ["full_event", "40042:<32-bytes lowercase hex of a pubkey>:abc", "<recommended relay URL, optional>"],
    ["url", "<string with PREVIEW url>"],
    ["dim", "800x600"]
  ],
  "content": "",
  ...
}

Full Event

A "Full Event" is of kind:40042. It has NIP-42 A tags the author can update at will with the pubkeys allowed to access it.

It uses the custom NIP-42 event serialization for events that require AUTH.

The .content and other tags aren't fixed. The structure depends on the kind of the public event it is protecting. For example, if it is protecting a kind:30023 event, it should have the structure defined on NIP-23.

Example:

{
  "kind": 40042,
  "pubkey": "<author_pubkey>",
  "tags": [
    ["d", "<random>"],
    ["A", "<author_pubkey>"], // important to keep author access right
    ["A", "<buyer_1_pubkey>"],
    ["A", "<buyer_2_pubkey>"],
    ["url", "https://some.place/file.webp"],
    ["dim", "800x600"]
  ],
  "content": "Happy New Year, my dear supporters!!",
  ...
}

Requesting the Event

The client is expected to initially request the public event. For example, a microblogging client will request kind:1 events as usual.

If one of these events includes a full_event tag, the client should request it with a filter that includes a #A filter key set to the client's user pubkey.

If the user has rights to access the full event, the relay will send it after the NIP-42 authentication flow.

For example: { "kinds": [40042], "authors": ["abc"], #d: ["xyz"], "#A": ["<client's user pubkey>"], "limit": 1 }