nips/51.md

NIP-51
======

Lists
-------------------------

`draft` `optional` `author:fiatjaf` `author:arcbtc` `author:monlovesmango` `author:eskema` `depends:33`

A "list" event is defined as having a list of public and/or private tags. Public tags will be listed in the event `tags`. Private tags will be encrypted in the event `content`. Encryption for private tags will use [NIP-04 - Encrypted Direct Message](04.md) encryption, using the list author's private and public key for the shared secret. A distinct event kind should be used for each list type created.

If a list type should only be defined once per user (like the 'Mute' list), the list type's events should follow the specification for [NIP-16 - Replaceable Events](16.md). These lists may be referred to as 'replaceable lists'.

Otherwise the list type's events should follow the specification for [NIP-33 - Parameterized Replaceable Events](33.md), where the list name will be used as the 'd' parameter. These lists may be referred to as 'parameterized replaceable lists'.

## Replaceable List Event Example

Lets say a user wants to create a 'Mute' list and has keys:
```
priv: fb505c65d4df950f5d28c9e4d285ee12ffaf315deef1fc24e3c7cd1e7e35f2b1
pub: b1a5c93edcc8d586566fde53a20bdb50049a97b15483cb763854e57016e0fa3d
```
The user wants to publicly include these users:

```json
["p", "3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d"],
["p", "32e1827635450ebb3c5a7d12c1f8e7b2b514439ac10a67eef3d9fd9c5c68e245"]
```
and privately include these users (below is the JSON that would be encrypted and placed in the event content):

```json
[
    ["p", "9ec7a778167afb1d30c4833de9322da0c08ba71a69e1911d5578d3144bb56437"],
    ["p", "8c0da4862130283ff9e67d889df264177a508974e2feb96de139804ea66d6168"]
]
```

Then the user would create a 'Mute' list event like below:

```json
{
  "kind": 10000,
  "tags": [
    ["p", "3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d"],
    ["p", "32e1827635450ebb3c5a7d12c1f8e7b2b514439ac10a67eef3d9fd9c5c68e245"],
  ],
  "content": "VezuSvWak++ASjFMRqBPWS3mK5pZ0vRLL325iuIL4S+r8n9z+DuMau5vMElz1tGC/UqCDmbzE2kwplafaFo/FnIZMdEj4pdxgptyBV1ifZpH3TEF6OMjEtqbYRRqnxgIXsuOSXaerWgpi0pm+raHQPseoELQI/SZ1cvtFqEUCXdXpa5AYaSd+quEuthAEw7V1jP+5TDRCEC8jiLosBVhCtaPpLcrm8HydMYJ2XB6Ixs=?iv=/rtV49RFm0XyFEwG62Eo9A==",
  ...other fields
}
```


## Parameterized Replaceable List Event Example

Lets say a user wants to create a 'Categorized People' list of `nostr` people and has keys:
```
priv: fb505c65d4df950f5d28c9e4d285ee12ffaf315deef1fc24e3c7cd1e7e35f2b1
pub: b1a5c93edcc8d586566fde53a20bdb50049a97b15483cb763854e57016e0fa3d
```
The user wants to publicly include these users:

```json
["p", "3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d"],
["p", "32e1827635450ebb3c5a7d12c1f8e7b2b514439ac10a67eef3d9fd9c5c68e245"]
```
and privately include these users (below is the JSON that would be encrypted and placed in the event content):

```json
[
    ["p", "9ec7a778167afb1d30c4833de9322da0c08ba71a69e1911d5578d3144bb56437"],
    ["p", "8c0da4862130283ff9e67d889df264177a508974e2feb96de139804ea66d6168"]
]
```

Then the user would create a 'Categorized People' list event like below:

```json
{
  "kind": 30000,
  "tags": [
    ["d", "nostr"],
    ["p", "3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d"],
    ["p", "32e1827635450ebb3c5a7d12c1f8e7b2b514439ac10a67eef3d9fd9c5c68e245"],
  ],
  "content": "VezuSvWak++ASjFMRqBPWS3mK5pZ0vRLL325iuIL4S+r8n9z+DuMau5vMElz1tGC/UqCDmbzE2kwplafaFo/FnIZMdEj4pdxgptyBV1ifZpH3TEF6OMjEtqbYRRqnxgIXsuOSXaerWgpi0pm+raHQPseoELQI/SZ1cvtFqEUCXdXpa5AYaSd+quEuthAEw7V1jP+5TDRCEC8jiLosBVhCtaPpLcrm8HydMYJ2XB6Ixs=?iv=/rtV49RFm0XyFEwG62Eo9A==",
  ...other fields
}
```

## List Event Kinds

| kind   | list type               |
| ------ | ----------------------- |
| 10000  | Mute                    |
| 10001  | Pin                     |
| 30000  | Categorized People      |
| 30001  | Categorized Bookmarks   |

### Mute List

An event with kind `10000` is defined as a replaceable list event (see [NIP-51 - Lists](51.md) for listing content a user wants to mute. Any standarized tag can be included in a Mute List.

### Pin List

An event with kind `10001` is defined as a replaceable list event (see [NIP-51 - Lists](51.md) for listing content a user wants to pin. Any standarized tag can be included in a Pin List.

### Categorized People List

An event with kind `30000` is defined as a parameterized replaceable list event (see [NIP-51 - Lists](51.md)) for categorizing people. The 'd' parameter for this event holds the category name of the list. The tags included in these lists MUST follow the format of kind 3 events as defined in [NIP-02 - Contact List and Petnames](02.md).

### Categorized Bookmarks List

An event with kind `30001` is defined as a parameterized replaceable list event (see [NIP-51 - Lists](51.md)) for categorizing bookmarks. The 'd' parameter for this event holds the category name of the list. Any standarized tag can be included in a Categorized Bookmarks List.