NIP-45 ====== Event Counts -------------- `draft` `optional` `author:staab` Relays may support the `COUNT` verb, which provide 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 a filter as specified in [NIP 01](01.md). Counts are returned using a `COUNT` response in the form `{count: }`. Relays may use probabilistic counts to reduce compute requirements. Examples: ``` # Followers count ["COUNT", "", {kinds: [3], '#p': []}] ["COUNT", "", {count: 238}] # Count posts and reactions ["COUNT", "", {kinds: [1, 7], authors: []}] ["COUNT", "", {count: 5}] ```