Register official Nostr event kind numbers via NIP proposal

[WilliamPenrose]

Background

SNAP currently uses three unregistered Nostr event kinds:

Kind	Purpose	NIP range
31337	Agent Card (replaceable)	30000-39999 (NIP-33)
21339	Ephemeral SNAP message	20000-29999 (NIP-16)
4339	Storable SNAP message	1000-9999 (regular)

These numbers were chosen to avoid known conflicts, but they are not officially registered with the Nostr community.

Proposal

Submit a NIP (Nostr Implementation Possibility) to register these event kinds, or adopt already-registered kinds if a better fit exists.

Steps

1. Survey existing NIPs for overlapping use cases (NIP-89 app handlers, NIP-90 data vending machines)
2. Draft a NIP describing SNAP agent discovery and encrypted messaging kinds
3. Submit PR to nostr-protocol/nips
4. If the community suggests different kind numbers, update the SDK defaults and migration guide

Why this matters

• Prevents future kind collisions as the Nostr ecosystem grows
• Gives SNAP protocol legitimacy in the Nostr community
• Other Nostr clients can recognize and handle SNAP events properly

References

• NIP-16: Event Treatment
• NIP-33: Parameterized Replaceable Events
• Current implementation: src/transport/NostrTransport.ts