nips/45.md
2023-04-17 13:31:18 -03:00

38 lines
1.3 KiB
Markdown

# NIP-45
## Event Counts
`draft` `optional` `author:staab`
Relays may support the `COUNT` verb, which provides a mechanism for obtaining event counts.
## Motivation
Some queries a client may want to execute against connected relays are prohibitively expensive, for example, in order to retrieve follower counts for a given pubkey, a client must query all kind-3 events referring to a given pubkey and count them. The result may be cached, either by a client or by a separate indexing server as an alternative, but both options erode the decentralization of the network by creating a second-layer protocol on top of Nostr.
## Filters and return values
This NIP defines a verb called `COUNT`, which accepts a subscription id and filters as specified in [NIP 01](01.md).
```json
["COUNT", <subscription_id>, <filters JSON>...]
```
Counts are returned using a `COUNT` response in the form `{count: <integer>}`. Relays may use probabilistic counts to reduce compute requirements.
```json
["COUNT", <subscription_id>, {"count": <integer>}]
```
Examples:
```json
# Followers count
["COUNT", <subscription_id>, {"kinds": [3], "#p": [<pubkey>]}]
["COUNT", <subscription_id>, {"count": 238}]
# Count posts and reactions
["COUNT", <subscription_id>, {"kinds": [1, 7], "authors": [<pubkey>]}]
["COUNT", <subscription_id>, {"count": 5}]
```