nips/C1.md

NIP-C1

Collaborative Ownership

draft optional

This NIP defines a mechanism for multiple pubkeys to collaboratively maintain addressable events while preserving backwards compatibility.

Motivation

Certain applications require shared ownership where:

1. Attribution matters: Each collaborator signs with their own key
2. Dynamic membership: Owners can be added or removed
3. Backwards compatibility: Non-supporting clients see normal events

Specification

Collaborative Pointer Event

A new addressable event kind 39382 serves as a pointer to collaboratively-owned content:

{
  "kind": 39382,
  "pubkey": "<creator-pubkey>",
  "tags": [
    ["d", "<target-kind>-<slug>"],
    ["k", "<target-kind>"],
    ["p", "<owner-1-pubkey>"],
    ["p", "<owner-2-pubkey>"],
    ["p", "<owner-3-pubkey>"],
    ["relay", "wss://relay1.example.com"],
    ["relay", "wss://relay2.example.com"]
  ],
  "content": "",
  "created_at": 1234567890
}

Tag Definitions

Tag	Required	Description
d	Yes	<target-kind>-<slug> - prevents collisions across kinds
k	Yes	Target event kind (avoids string parsing of d tag)
p	Yes	Owner pubkeys (one or more)
relay	No	Relay hints; if absent, use NIP-65 outbox model

Resolution Algorithm

To resolve the current state of collaboratively-owned content:

1. Parse the 39382 pointer event to extract owners (p tags) and target kind (k tag)
2. Extract the slug from the d tag (everything after the first -)
3. Query: {"kinds": [<target-kind>], "authors": [<all-owners>], "#d": ["<slug>"], "limit": 1}
4. Use relay tags if present; otherwise fall back to NIP-65 outbox relays
5. Return the event with the highest created_at

Back-Reference (Optional)

Target events MAY include an a tag pointing to the 39382 pointer:

{
  "kind": 30023,
  "tags": [
    ["d", "my-article"],
    ["a", "39382:<pointer-creator-pubkey>:30023-my-article"]
  ]
}

This enables clients to discover that an event is part of a collaborative set.

Example

Pointer Event

{
  "kind": 39382,
  "pubkey": "alice-pubkey",
  "tags": [
    ["d", "30023-collaborative-guide"],
    ["k", "30023"],
    ["p", "alice-pubkey"],
    ["p", "bob-pubkey"],
    ["p", "carol-pubkey"],
    ["relay", "wss://relay.example.com"]
  ],
  "content": ""
}

Target Article (by any owner)

{
  "kind": 30023,
  "pubkey": "bob-pubkey",
  "tags": [
    ["d", "collaborative-guide"],
    ["title", "A Collaborative Guide"],
    ["a", "39382:alice-pubkey:30023-collaborative-guide"]
  ],
  "content": "..."
}

Client Resolution

1. Client receives naddr for the 39382 pointer
2. Parses owners: [alice, bob, carol]
3. Queries: {"kinds": [30023], "authors": ["alice", "bob", "carol"], "#d": ["collaborative-guide"], "limit": 1}
4. Returns most recent version regardless of which owner published it