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 a filter as specified in [NIP 01](01.md).
Counts are returned using a `COUNT` response in the form `{count: <integer>}`. Relays may use probabilistic counts to reduce compute requirements.
