NIP: 26
=======

Delegated Event Signing
-----

`draft` `optional` `author:markharding` `author:minds`

This NIP defines how events can be delegated so that they can be signed by other keypairs.

Another application of this proposal is to abstract away the use of the 'root' keypairs when interacting with clients. For example, a user could generate new keypairs for each client they wish to use and authorize those keypairs to generate events on behalf of their root pubkey, where the root keypair is stored in cold storage. 

#### Introducing the 'delegation' tag

This NIP introduces a new tag: `delegation` which is formatted as follows:

```json
[
  "delegation",
  <pubkey of the delegator>,
  <conditions query string>,
  <64-bytes schnorr signature of the sha256 hash of the delegation token>
]
```

##### Delegation Token

The **delegation token** should be a 64-bytes schnorr signature of the sha256 hash of the following string:

```
nostr:delegation:<pubkey of publisher (delegatee)>:<conditions query string>
```

For example, the token `c33c88ba78ec3c760e49db591ac5f7b129e3887c8af7729795e85a0588007e5ac89b46549232d8f918eefd73e726cb450135314bfda419c030d0b6affe401ec1` is signed by `86f0689bd48dcd19c67a19d994f938ee34f251d8c39976290955ff585f2db42e` and consists of:

```json
nostr:delegation:62903b1ff41559daf9ee98ef1ae67cc52f301bb5ce26d14baba3052f649c3f49:kind=1&created_at>1640995200
```

#### Example

Below is an example of an event published by `62903b1ff41559daf9ee98ef1ae67cc52f301bb5ce26d14baba3052f649c3f49`, on behalf of `86f0689bd48dcd19c67a19d994f938ee34f251d8c39976290955ff585f2db42e`.

```json
{
  "id": "a080fd288b60ac2225ff2e2d815291bd730911e583e177302cc949a15dc2b2dc",
  "pubkey": "62903b1ff41559daf9ee98ef1ae67cc52f301bb5ce26d14baba3052f649c3f49",
  "created_at": 1660896109,
  "kind": 1,
  "tags": [
    [
      "delegation",
      "86f0689bd48dcd19c67a19d994f938ee34f251d8c39976290955ff585f2db42e",
      "kind=1&created_at>1640995200",
      "c33c88ba78ec3c760e49db591ac5f7b129e3887c8af7729795e85a0588007e5ac89b46549232d8f918eefd73e726cb450135314bfda419c030d0b6affe401ec1"
    ]
  ],
  "content": "Hello world",
  "sig": "cd4a3cd20dc61dcbc98324de561a07fd23b3d9702115920c0814b5fb822cc5b7c5bcdaf3fa326d24ed50c5b9c8214d66c75bae34e3a84c25e4d122afccb66eb6"
}
```


#### Relay & Client Querying Support

Relays should answer requests such as `["REQ", "", {"authors": ["A"]}]` by querying both the `pubkey` and delegation tags `[1]` value.