Event-specific zap markers

57.md

@@ -24,7 +24,7 @@ Having lightning receipts on nostr allows clients to display lightning payments
 
 ### Client side
 
-1. Calculate the lnurl pay request url for a user from the lud06 or lud16 field on their profile
+1. Calculate the lnurl pay request url for a user from the `zap` tag on the event being zapped, or alternatively the lud06 or lud16 field on their profile.
 
 2. Fetch the lnurl pay request static endpoint (`https://host.com/.well-known/lnurlp/user`) and gather the `allowsNostr` and `nostrPubkey` fields. If `allowsNostr` exists and it is `true`, and if `nostrPubkey` exists and is a valid BIP 340 public key in hex, associate this information with the user. The `nostrPubkey` is the `zapper`'s pubkey, and it is used to authorize zaps sent to that user.
 
@@ -34,6 +34,18 @@ Having lightning receipts on nostr allows clients to display lightning payments
 
 5. Pay this invoice or pass it to an app that can pay the invoice. Once it's paid, a `zap note` will be created by the `zapper`.
 
+### `zap` tag on zapped event
+
+When an event includes a `zap` tag, clients SHOULD calculate the lnurl pay request based on it's value instead of the profile's field. An optional third argument on the tag specifies the type of value, either `lud06` or `lud16`.
+
+```json
+{
+    "tags": [
+        [ "zap", "[email protected]", "lud16" ]
+    ]
+}
+```
+
 ### LNURL Server side
 
 The lnurl server will need some additional pieces of information so that clients can know that zap invoices are supported: