update

docs/nips/45.md

@@ -0,0 +1,60 @@
+NIP-45
+======
+
+Event Counts
+------------
+
+`draft` `optional`
+
+Relays may support the verb `COUNT`, 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 only to 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 the verb `COUNT`, which accepts a query id and filters as specified in [NIP 01](01.md) for the verb `REQ`. Multiple filters are OR'd together and aggregated into a single count result.
+
+```
+["COUNT", <query_id>, <filters JSON>...]
+```
+
+Counts are returned using a `COUNT` response in the form `{"count": <integer>}`. Relays may use probabilistic counts to reduce compute requirements.
+In case a relay uses probabilistic counts, it MAY indicate it in the response with `approximate` key i.e. `{"count": <integer>, "approximate": <true|false>}`.
+
+```
+["COUNT", <query_id>, {"count": <integer>}]
+```
+
+Whenever the relay decides to refuse to fulfill the `COUNT` request, it MUST return a `CLOSED` message.
+
+## Examples
+
+### Followers count
+
+```
+["COUNT", <query_id>, {"kinds": [3], "#p": [<pubkey>]}]
+["COUNT", <query_id>, {"count": 238}]
+```
+
+### Count posts and reactions
+
+```
+["COUNT", <query_id>, {"kinds": [1, 7], "authors": [<pubkey>]}]
+["COUNT", <query_id>, {"count": 5}]
+```
+
+### Count posts approximately
+
+```
+["COUNT", <query_id>, {"kinds": [1]}]
+["COUNT", <query_id>, {"count": 93412452, "approximate": true}]
+```
+
+### Relay refuses to count
+
+```
+["COUNT", <query_id>, {"kinds": [1059], "#p": [<pubkey>]}]
+["CLOSED", <query_id>, "auth-required: cannot count other people's DMs"]
+```