# NIP-1078 ## Arbitrary custom app data `draft` `optional` `author:BlowaterNostr` ## Nostr event This NIP specifies the use of event kind `1078` which is almost identical to [30078](https://github.com/nostr-protocol/nips/blob/master/78.md) except that it's not a replacible event. ### Format #### Private Configs Private config should be encrypted using Kind-4's algorithm and stored in `content`. Technically the plain text content can be in any format, but it's best to use a JSON format of the following shape ``` content: { "client": "the client name, url for web client or NIP-89 identifier" ... the rest can be whatever the client author decides to be. } ``` #### Public Configs Similar to [NIP-78](https://github.com/BlowaterNostr/nips/blob/master/78.md#nostr-event), configs should be stored in `tags` and can be anything. ## Some use cases The reason to not having a 30078 is that some clients want to implement local state changes as [CRDTs](https://crdt.tech/), meaning support cumulative and associative mutations Cumulative and associative means the order of applying operations doesn't change the final result as long as the same set of operations are applied. Using regular events can reserve the event/operation history thus the client can recompute the final state easily. [Figma uses CRDT to implement their vector design system.](https://www.figma.com/blog/how-figmas-multiplayer-technology-works/) ## Implementations For example, in [Blowater](https://blowater.deno.dev), Pin/Unpin Contacts is implemented as regular events to achieve better consistency. Event set [`Pin Npub X`, `Unpin NpubX`, `Pin Npub Y`] will result in a pin list of `[Y]` no matter how the order is shifted. Many other operations are best implemented as CRDTs as well.