Display push notifications for knocks

libraries/push/impl/src/main/kotlin/io/element/android/libraries/push/impl/notifications/DefaultNotifiableEventResolver.kt

@@ -36,6 +36,7 @@ import io.element.android.libraries.matrix.api.media.isPreviewEnabled
 import io.element.android.libraries.matrix.api.notification.NotificationContent
 import io.element.android.libraries.matrix.api.notification.NotificationData
 import io.element.android.libraries.matrix.api.permalink.PermalinkParser
+import io.element.android.libraries.matrix.api.room.RoomMembershipState
 import io.element.android.libraries.matrix.api.room.join.JoinRule
 import io.element.android.libraries.matrix.api.timeline.item.event.AudioMessageType
 import io.element.android.libraries.matrix.api.timeline.item.event.EmoteMessageType
@@ -319,6 +320,29 @@ class DefaultNotifiableEventResolver(
                 Timber.tag(loggerTag.value).d("Ignoring notification for sticker")
                 throw NotificationResolverException.EventFilteredOut
             }
+            is NotificationContent.StateEvent.RoomMemberContent -> {
+                // MSC4506: the homeserver pushes knocks to users who can act on them.
+                if (content.membershipState == RoomMembershipState.KNOCK) {
+                    val notifiableMessageEvent = buildNotifiableMessageEvent(
+                        sessionId = userId,
+                        senderId = content.userId,
+                        roomId = roomId,
+                        eventId = eventId,
+                        noisy = isNoisy,
+                        timestamp = this.timestamp,
+                        senderDisambiguatedDisplayName = getDisambiguatedDisplayName(content.userId),
+                        body = stringProvider.getString(R.string.notification_knock_request_body),
+                        roomName = roomDisplayName,
+                        roomIsDm = isDm,
+                        roomAvatarPath = roomAvatarUrl,
+                        senderAvatarPath = senderAvatarUrl,
+                    )
+                    ResolvedPushEvent.Event(notifiableMessageEvent)
+                } else {
+                    Timber.tag(loggerTag.value).d("Ignoring notification for membership ${content.membershipState}")
+                    throw NotificationResolverException.EventFilteredOut
+                }
+            }
             NotificationContent.MessageLike.Beacon -> {
                 Timber.tag(loggerTag.value).d("Ignoring notification for beacon")
                 throw NotificationResolverException.EventFilteredOut
@@ -341,7 +365,6 @@ class DefaultNotifiableEventResolver(
                 )
                 ResolvedPushEvent.Event(notifiableEventMessage)
             }
-            is NotificationContent.StateEvent.RoomMemberContent,
             NotificationContent.StateEvent.PolicyRuleRoom,
             NotificationContent.StateEvent.PolicyRuleServer,
             NotificationContent.StateEvent.PolicyRuleUser,

libraries/push/impl/src/main/res/values/temporary.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ Copyright (c) 2026 Element Creations Ltd.
+  ~
+  ~ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+  ~ Please see LICENSE files in the repository root for full details.
+  -->
+
+<resources>
+    <!-- Body of the notification shown to users who can act on a knock (MSC4506 knock push rule). -->
+    <string name="notification_knock_request_body">"Requested to join"</string>
+</resources>

libraries/push/impl/src/test/kotlin/io/element/android/libraries/push/impl/notifications/DefaultNotifiableEventResolverTest.kt

@@ -652,6 +652,28 @@ class DefaultNotifiableEventResolverTest : RobolectricTest() {
         assertThat(result.getEvent(request)).isEqualTo(Result.success(expectedResult))
     }
 
+    @Test
+    fun `resolve RoomMemberContent knock`() = runTest {
+        val sut = createDefaultNotifiableEventResolver(
+            notificationResult = Result.success(
+                mapOf(
+                    AN_EVENT_ID to Result.success(aNotificationData(
+                        content = NotificationContent.StateEvent.RoomMemberContent(
+                            userId = A_USER_ID_2,
+                            membershipState = RoomMembershipState.KNOCK
+                        )
+                    ))
+                )
+            )
+        )
+        val request = aPushRequest(A_SESSION_ID, A_ROOM_ID, AN_EVENT_ID, "firebase")
+        val result = sut.resolveEvents(A_SESSION_ID, listOf(request))
+        val expectedResult = ResolvedPushEvent.Event(
+            aNotifiableMessageEvent(body = "Requested to join")
+        )
+        assertThat(result.getEvent(request)).isEqualTo(Result.success(expectedResult))
+    }
+
     @Test
     fun `resolve RoomMemberContent other`() = runTest {
         val sut = createDefaultNotifiableEventResolver(