# NIP-59: Relay Status

`draft` `optional` `author:dskvr`

This NIP defines `30303`, a parameterized replaceable event [NIP-33], referred to as Relay Statuses. Relay Statuses use tags extensively and **may** have `.content` populated with Stringified JSON.

## Purpose 
To store computationally expensive relay meta-data from active relays as events on nostr.

## Personas 
- **Publishers** generate and push `30303` events. Events **should** be published at a regular interval. Events **must** implement `NIP-40`. 
- **Consumers** aggregate `30303` for insight on relays. Some example consumers are a social client or relay status client. 

## schema

### `event.tags`
Relay status events have **two** (2) required tags and **eight** (8) optional tags. Relay status events introduce **one** (1) new indexable tag (NIP-12)
 
The tags should be used to represent the Relay's abilities and meta at a point in time. Below the `tags schema` is expressed using pseudo-types for reasons of communication and brevity, for example `tagDescriptor[]`.

1. `"d" == tagId[0]` The relay URL. The `#d` tag **must** be included in the `event.tags[]` array. `tagId[1]` **must** be the relay websocket URL. The URL **should** be normalized. 
```json
["d", "wss://history.nostr.watch/"] //tagId[]
```
2. `"expiration" == tagExpiration[0]` [NIP-40]. The `tagExpiration[]` tag **must** be included in the `event.tags[]` array. `tagExpiration[1]` **should** be set to a future timestamp that correlates with the publisher's intended update frequency. 
```json
["expiration", "1600000000"] //tagExpiration[]
```
3. `"t" == tagTopic[0]` Topics relevant to the relay. `tagTopic[]` **may** be included in the `event.tags[]` array. `tagTopic[1]` **should** be string. There **should** be no more than **twenty (20)** `tagTopic[]` arrays. 
```json
["t", "bitcoin"]  //tagTopic[]
```
4. `"g" == tagGeo[0]` Relay Geo Data. `tagGeo[]` **may** be included in the `event.tags[]` array. `tagGeo[1]` **must** be string and **should** be a geohash. There **may** be strings defined in the key range `2+` (`tagGeo[2...]`) and they **must** be strings if set. `tagGeo[]` items **should** be descending by precision. There **should** be no more than **one (1)** `tagGeo[]` per event.  
```json
["g", "ww8p1r4t8", "Amsterdam", "NL", "EU", "Earth", "Sol", "Milky Way"] //tagGeo[]
```
5. `"read" == tagRead[0]` Was able to read from the relay. `tagRead[]` **may** be included in the `event.tags[]` array. `tagRead[1]` **must** be type string as exactly `true` or `false`
```json
["read", "true"]     //tagRead[]
```
6. `"write" == tagWrite[0]` Was able to write to the relay. `tagWrite[]` **may** be included in the `event.tags[]` array. `tagWrite[1]` **must** be type string as exactly `true` or `false`
```json
["write", "false"]    //tagWrite[]
```
7. `"ssl" == tagSsl[0]` Is the relay's SSL valid. `tagSsl[]` **may** be included in the `event.tags[]` array. `tagSsl[1]` **must** be type string as exactly `true` or `false`
```json
["ssl", "true"]     //tagSsl[]
```
8. `"ip" == tagIp[0]` Relay IP. `tagIp[]` **may** be included in the `event.tags[]` array. `tagIp[1]` **must** be string. There **may** be more than one (1) `tagIp[]` 
```json
["ip", "1.1.1.1"],  //tagIp[]
["ip", "2001:db8:3333:4444:5555:6666:7777:8888"] //tagIp[]
```
9. `"events" == tagEvents[0]` Number of events on relay. `tagEvents[]` **may** be included in the `event.tags[]` array. `tagEvents[1]` **must** be string. There **should** only be **one (1)** `tagEvents[]` 
```json
["events", "502341"],  //tagEvents[]
```
10. `"users" == tagUsers[0]` Relay IP. `tagUsers[]` **may** be included in the `event.tags[]` array. `tagUsers[1]` **must** be string. There **should** be no more than **one (1)** `tagUsers[]` 
```json
["users","37482"] //tagUsers[]
```


Example with Minimum Requirements: 
```json
{
  "id": "<eventid>",
  "pubkey": "<pubkey>",
  "created_at": "<created_at>",
  "signature": "<signature>",
  "content": "",
  "tags": [  
    ["d","wss://relay.snort.social/"],
    ["expiration", "1600000000"]
  ]
}
```

Example with all Tags: 
```json
{
  "id": "<eventid>",
  "pubkey": "<pubkey>",
  "created_at": "<created_at>",
  "signature": "<signature>",
  "content": "{}",
  "tags": [  
    ["d","wss://some.relay/"],
    ["expiration", "1600000000"],
    ["t","nostrica"],
    ["t","bitcoin"],
    ["g","ww8p1r4t8","Amsterdam","NL","EU","Earth"],
    ["ip","1.1.1.1"],
    ["ip","2001:db8:3333:4444:5555:6666:7777:8888"],
    ["read","true"],
    ["write","false"],
    ["ssl","true"],
    ["events", "502341"],
    ["users","37482"]
  ]
}
```

### `event.content` _optional_
The `.content` of these events **may** be empty. `.content` **may** contain stringified JSON. The parsed JSON has a flexible schema, all members are optional. The parsed `.content` JSON **should** be extended by NIPs. 

## Testing Criteria
The testing criteria to determine conditions defined in event's tags **may** be subjective and **may** vary between publishers.

## Consumption
The data in `30303` **may** be erroneous, intentionally or otherwise. Where accuracy is required, the data in `30303` events **should** be subscribed to by populating the `authors` filter array with the pubkeys of trusted **publishers**

## Use Cases 
- Aggregate relays quickly.
- A lite social client identifies relays that were recently reported to be online without client-side tests
- A social client may find relays where a particular topic is popular.
- A social client may find relays based on their geographic proximity
- A status client shows relay statuses
- Relays self-report statuses and/or metadata in `.content` signed by their NIP-11 `pubkey`.