Signs for just one auth event to register with the push notification service instead of the dozens of events, one per relay.

amethyst/src/main/java/com/vitorpamplona/amethyst/model/Account.kt

@@ -2358,6 +2358,16 @@ class Account(
         RelayAuthEvent.create(relayUrl, challenge, signer, onReady = onReady)
     }
 
+    fun createAuthEvent(
+        relayUrls: List<String>,
+        challenge: String,
+        onReady: (RelayAuthEvent) -> Unit,
+    ) {
+        if (!isWriteable()) return
+
+        RelayAuthEvent.create(relayUrls, challenge, signer, onReady = onReady)
+    }
+
     fun isInPrivateBookmarks(
         note: Note,
         onReady: (Boolean) -> Unit,

amethyst/src/main/java/com/vitorpamplona/amethyst/service/notifications/RegisterAccounts.kt

@@ -55,7 +55,7 @@ class RegisterAccounts(
 
     private suspend fun signAllAuths(
         notificationToken: String,
-        remainingTos: List<Pair<Account, String>>,
+        remainingTos: List<Pair<Account, List<String>>>,
         output: MutableList<RelayAuthEvent>,
         onReady: (List<RelayAuthEvent>) -> Unit,
     ) {
@@ -100,7 +100,7 @@ class RegisterAccounts(
     ) {
         val readyToSend =
             accounts
-                .map {
+                .mapNotNull {
                     Log.d(tag, "Register Account ${it.npub}")
 
                     val acc = LocalPreferences.loadCurrentAccountFromEncryptedStorage(it.npub)
@@ -131,13 +131,17 @@ class RegisterAccounts(
 
                         Log.d(tag, "Register Account ${acc.userProfile().toBestDisplayName()} Kind3 Reads ${readKind3Relays.joinToString(", ")}")
 
-                        (nip65Read + nip17Read + readKind3Relays).map {
+                        val relays = (nip65Read + nip17Read + readKind3Relays)
-                            Pair(acc, it)
+
+                        if (relays.isNotEmpty()) {
+                            Pair(acc, relays)
+                        } else {
+                            null
                         }
                     } else {
-                        emptyList<Pair<Account, String>>()
+                        null
                     }
-                }.flatten()
+                }
 
         val listOfAuthEvents = mutableListOf<RelayAuthEvent>()
         signAllAuths(

quartz/src/main/java/com/vitorpamplona/quartz/events/RelayAuthEvent.kt

@@ -56,5 +56,23 @@ class RelayAuthEvent(
                 )
             signer.sign(createdAt, KIND, tags, content, onReady)
         }
+
+        fun create(
+            relays: List<String>,
+            challenge: String,
+            signer: NostrSigner,
+            createdAt: Long = TimeUtils.now(),
+            onReady: (RelayAuthEvent) -> Unit,
+        ) {
+            val content = ""
+            val tags =
+                relays
+                    .map {
+                        arrayOf("relay", it)
+                    }.plusElement(
+                        arrayOf("challenge", challenge),
+                    ).toTypedArray()
+            signer.sign(createdAt, KIND, tags, content, onReady)
+        }
     }
 }