# NIPs NIPs stand for **Nostr Implementation Possibilities**. They exist to document what MUST, what SHOULD and what MAY be implemented by [Nostr](https://github.com/fiatjaf/nostr)-compatible _relay_ and _client_ software. - [NIP-01: Basic protocol flow description](01.md) - [NIP-02: Contact List and Petnames](02.md) - [NIP-03: OpenTimestamps Attestations for Events](03.md) - [NIP-04: Encrypted Direct Message](04.md) - [NIP-05: Mapping Nostr keys to DNS-based internet identifiers](05.md) - [NIP-06: Basic key derivation from mnemonic seed phrase](06.md) - [NIP-07: `window.nostr` capability for web browsers](07.md) - [NIP-08: Handling Mentions](08.md) - [NIP-09: Event Deletion](09.md) - [NIP-10: Conventions for clients' use of `e` and `p` tags in text events.](10.md) - [NIP-11: Relay Information Document](11.md) - [NIP-12: Generic Tag Queries](12.md) - [NIP-13: Proof of Work](13.md) - [NIP-14: Subject tag in text events.](14.md) - [NIP-15: End of Stored Events Notice](15.md) - [NIP-16: Event Treatment](16.md) - [NIP-22: Event created_at Limits](22.md) - [NIP-25: Reactions](25.md) ## Event Kinds | kind | description | NIP | |------|---------------------------|------| | 0 | Metadata | 1, 5 | | 1 | Text | 1 | | 2 | Recommend Relay | 1 | | 3 | Contacts | 2 | | 4 | Encrypted Direct Messages | 4 | | 5 | Event Deletion | 9 | | 7 | Reaction | 25 | Please update this list when proposing NIPs introducing new event kinds. When experimenting with kinds, keep in mind the classification introduced by [NIP-16](16.md). ## Criteria for acceptance of NIPs 1. They should be implemented somewhere at least as a prototype somewhere. 2. They should make sense. 3. Other rules will be made up when necessary. ## License All NIPs are public domain.