feat: relay-group threads (kind 11) as a secondary view

Closes the Flotilla interop gap where NIP-29 groups also carry kind-11
"threads" (forum-style posts) that Amethyst's chat-only room view dropped.
Threads are a secondary surface, kept out of the kind-9 chat feed — a
Threads button in the group top bar, mirroring Discord/Slack.

- RelayGroupChannel: a separate `threads` collection (kind-11 notes) with a
  reactive StateFlow, distinct from the chat timeline.
- LocalCache: attach kind-11 to channel.threads (same host-pinned + own-send
  null-relay routing as chat messages).
- Host-pinned RelayGroupThreadsFilterAssembler (kinds 11 + 1111 scoped by
  `#h`), active only while a group's Threads screen is open; fetching the
  1111 comments too means opening a thread has its replies already cached.
- RelayGroupThreadsScreen lists a group's threads (title, author, preview,
  reply count) and opens each in the existing thread view (Route.Note) for
  the full comment tree — no bespoke detail screen needed. Members start a
  thread via NewRelayGroupThreadDialog → Account.postRelayGroupThread
  (ThreadEvent.build(body, title){ hTag }).
- Route.RelayGroupThreads + a Forum icon in the group top bar.

Verified: kind-11 with h + title round-trips and is queryable by #h against
an embedded relay (the exact filter Flotilla uses); commons threads-collection
test (dedup/flow/remove) passes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B5MLY4hq5LXJ2D5WeLRyXj

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

@@ -203,6 +203,7 @@ import com.vitorpamplona.quartz.nip19Bech32.entities.NPub
 import com.vitorpamplona.quartz.nip19Bech32.entities.NRelay
 import com.vitorpamplona.quartz.nip19Bech32.entities.NSec
 import com.vitorpamplona.quartz.nip29RelayGroups.GroupId
+import com.vitorpamplona.quartz.nip29RelayGroups.hTag
 import com.vitorpamplona.quartz.nip29RelayGroups.metadata.GroupMetadataEvent
 import com.vitorpamplona.quartz.nip29RelayGroups.moderation.CreateGroupEvent
 import com.vitorpamplona.quartz.nip29RelayGroups.moderation.CreateInviteEvent
@@ -262,6 +263,7 @@ import com.vitorpamplona.quartz.nip72ModCommunities.rules.tags.KindRuleTag
 import com.vitorpamplona.quartz.nip72ModCommunities.rules.tags.PubkeyRuleTag
 import com.vitorpamplona.quartz.nip72ModCommunities.rules.tags.WotTag
 import com.vitorpamplona.quartz.nip78AppData.AppSpecificDataEvent
+import com.vitorpamplona.quartz.nip7DThreads.ThreadEvent
 import com.vitorpamplona.quartz.nip88Polls.poll.PollEvent
 import com.vitorpamplona.quartz.nip88Polls.response.PollResponseEvent
 import com.vitorpamplona.quartz.nip90Dvms.contentDiscoveryRequest.NIP90ContentDiscoveryRequestEvent
@@ -1516,6 +1518,16 @@ class Account(
         return id
     }
 
+    /** Post a kind 11 thread (forum-style) to the group, scoped by its `h` tag. */
+    suspend fun postRelayGroupThread(
+        channel: RelayGroupChannel,
+        title: String,
+        body: String,
+    ) {
+        val template = ThreadEvent.build(body, title) { hTag(channel.groupId.id) }
+        signAndSendPrivatelyOrBroadcast(template) { channel.relays().toList() }
+    }
+
     /** Mint a kind 9009 invite code for the group (admin/moderator only). */
     suspend fun createRelayGroupInvite(
         channel: RelayGroupChannel,

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

@@ -259,6 +259,7 @@ import com.vitorpamplona.quartz.nip72ModCommunities.definition.CommunityDefiniti
 import com.vitorpamplona.quartz.nip72ModCommunities.follow.CommunityListEvent
 import com.vitorpamplona.quartz.nip75ZapGoals.GoalEvent
 import com.vitorpamplona.quartz.nip78AppData.AppSpecificDataEvent
+import com.vitorpamplona.quartz.nip7DThreads.ThreadEvent
 import com.vitorpamplona.quartz.nip84Highlights.HighlightEvent
 import com.vitorpamplona.quartz.nip85TrustedAssertions.list.TrustProviderListEvent
 import com.vitorpamplona.quartz.nip85TrustedAssertions.users.ContactCardEvent
@@ -1821,6 +1822,26 @@ object LocalCache : ILocalCache, ICacheProvider {
         }
     }
 
+    /**
+     * Same routing as [attachToRelayGroupIfScoped] but for kind-11 threads, which
+     * are kept in a separate collection from the chat timeline so the two content
+     * types don't mix in one feed.
+     */
+    private fun attachThreadToRelayGroupIfScoped(
+        event: Event,
+        relay: NormalizedRelayUrl?,
+    ) {
+        val groupId = event.groupId() ?: return
+        val note = getOrCreateNote(event.id)
+        if (note.event == null) return
+
+        if (relay != null) {
+            getOrCreateRelayGroupChannel(GroupId(groupId, relay)).addThread(note)
+        } else {
+            relayGroupChannels.filter { key, _ -> key.id == groupId }.forEach { it.addThread(note) }
+        }
+    }
+
     fun consume(
         event: LiveActivitiesChatMessageEvent,
         relay: NormalizedRelayUrl?,
@@ -4031,6 +4052,12 @@ object LocalCache : ILocalCache, ICacheProvider {
                     }
                 }
 
+                is ThreadEvent -> {
+                    consumeRegularEvent(event, relay, wasVerified).also {
+                        attachThreadToRelayGroupIfScoped(event, relay)
+                    }
+                }
+
                 is PollResponseEvent -> {
                     consume(event, relay, wasVerified)
                 }

amethyst/src/main/java/com/vitorpamplona/amethyst/service/relayClient/reqCommand/RelaySubscriptionsCoordinator.kt

@@ -39,6 +39,7 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.privateDM.datasource.
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.datasource.ChannelFilterAssembler
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.datasource.RelayGroupDirectoryFilterAssembler
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.datasource.RelayGroupRosterFilterAssembler
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.datasource.RelayGroupThreadsFilterAssembler
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.rooms.datasource.ChatroomListFilterAssembler
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chess.datasource.ChessFilterAssembler
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.communities.datasource.CommunityFilterAssembler
@@ -117,6 +118,7 @@ class RelaySubscriptionsCoordinator(
     val channel = ChannelFilterAssembler(client)
     val relayGroupDirectory = RelayGroupDirectoryFilterAssembler(client)
     val relayGroupRoster = RelayGroupRosterFilterAssembler(client)
+    val relayGroupThreads = RelayGroupThreadsFilterAssembler(client)
     val chatroom = ChatroomFilterAssembler(client)
     val community = CommunityFilterAssembler(client)
     val gitRepository = RepositoryFilterAssembler(client)
@@ -180,6 +182,7 @@ class RelaySubscriptionsCoordinator(
         listOf(
             relayGroupDirectory,
             relayGroupRoster,
+            relayGroupThreads,
             account,
             accountForeground,
             home,

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/AppNavigation.kt

@@ -109,6 +109,7 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayG
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.RelayGroupChannelListScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.RelayGroupChatScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.RelayGroupMembersScreen
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.RelayGroupThreadsScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.RelayGroupsHomeScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.rooms.MessagesScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.share.ShareToDMScreen
@@ -589,6 +590,15 @@ fun BuildNavigation(
             )
         }
 
+        composableFromEndArgs<Route.RelayGroupThreads> {
+            RelayGroupThreadsScreen(
+                id = it.id,
+                relayUrl = it.relayUrl,
+                accountViewModel = accountViewModel,
+                nav = nav,
+            )
+        }
+
         composableFromEndArgs<Route.RelayGroupBrowse> {
             RelayGroupBrowseScreen(
                 accountViewModel = accountViewModel,

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/routes/Routes.kt

@@ -653,6 +653,11 @@ sealed class Route {
         val relayUrl: String,
     ) : Route()
 
+    @Serializable data class RelayGroupThreads(
+        val id: String,
+        val relayUrl: String,
+    ) : Route()
+
     @Serializable object RelayGroups : Route()
 
     @Serializable object RelayGroupBrowse : Route()

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AccountViewModel.kt

@@ -1452,6 +1452,12 @@ class AccountViewModel(
         code: String,
     ) = launchSigner { account.createRelayGroupInvite(channel, code) }
 
+    fun postRelayGroupThread(
+        channel: RelayGroupChannel,
+        title: String,
+        body: String,
+    ) = launchSigner { account.postRelayGroupThread(channel, title, body) }
+
     fun removeRelayGroupUser(
         channel: RelayGroupChannel,
         pubkey: HexKey,

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/relayGroup/NewRelayGroupThreadDialog.kt

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupChannel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+
+/**
+ * Start a new kind-11 thread in the group: a required title plus a body. Publishes
+ * to the group's host relay (the relay accepts it only from a member).
+ */
+@Composable
+fun NewRelayGroupThreadDialog(
+    channel: RelayGroupChannel,
+    accountViewModel: AccountViewModel,
+    onDismiss: () -> Unit,
+) {
+    var title by remember { mutableStateOf("") }
+    var body by remember { mutableStateOf("") }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text(stringRes(R.string.relay_group_thread_new)) },
+        text = {
+            Column {
+                OutlinedTextField(
+                    value = title,
+                    onValueChange = { title = it },
+                    singleLine = true,
+                    label = { Text(stringRes(R.string.relay_group_thread_title_label)) },
+                    modifier = Modifier.fillMaxWidth(),
+                )
+                OutlinedTextField(
+                    value = body,
+                    onValueChange = { body = it },
+                    label = { Text(stringRes(R.string.relay_group_thread_body_label)) },
+                    modifier = Modifier.fillMaxWidth().heightIn(min = 120.dp).padding(top = 8.dp),
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(
+                enabled = title.isNotBlank() && body.isNotBlank(),
+                onClick = {
+                    accountViewModel.postRelayGroupThread(channel, title.trim(), body.trim())
+                    onDismiss()
+                },
+            ) {
+                Text(stringRes(R.string.relay_group_thread_post))
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) { Text(stringRes(R.string.cancel)) }
+        },
+    )
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/relayGroup/RelayGroupThreadsScreen.kt

@@ -0,0 +1,221 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material3.FloatingActionButton
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
+import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupChannel
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.Route
+import com.vitorpamplona.amethyst.ui.navigation.topbars.TopBarExtensibleWithBackButton
+import com.vitorpamplona.amethyst.ui.note.UserPicture
+import com.vitorpamplona.amethyst.ui.note.UsernameDisplay
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.datasource.RelayGroupThreadsSubscription
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.amethyst.ui.theme.Size35dp
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
+import com.vitorpamplona.quartz.nip29RelayGroups.GroupId
+import com.vitorpamplona.quartz.nip7DThreads.ThreadEvent
+
+/**
+ * A group's forum-style threads (kind 11) — the secondary content type kept out of
+ * the kind-9 chat feed. Streams the group's threads + their comments via
+ * [RelayGroupThreadsSubscription]; tapping a thread opens the generic thread view
+ * ([Route.Note]) with its comment tree. Members can start a new thread.
+ */
+@Composable
+fun RelayGroupThreadsScreen(
+    id: HexKey,
+    relayUrl: String,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val relay = remember(relayUrl) { RelayUrlNormalizer.normalizeOrNull(relayUrl) } ?: return
+    val channelId = remember(id, relay) { GroupId(id, relay) }
+
+    LoadRelayGroupChannel(channelId, accountViewModel) { channel ->
+        RelayGroupThreads(channel, accountViewModel, nav)
+    }
+}
+
+@Composable
+private fun RelayGroupThreads(
+    channel: RelayGroupChannel,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    RelayGroupThreadsSubscription(channel, accountViewModel.dataSources().relayGroupThreads, accountViewModel)
+
+    val threads by channel.threads.collectAsStateWithLifecycle()
+    var showCompose by remember { mutableStateOf(false) }
+
+    Scaffold(
+        topBar = {
+            TopBarExtensibleWithBackButton(
+                title = {
+                    Column {
+                        Text(
+                            text = stringRes(R.string.relay_group_threads_title),
+                            fontWeight = FontWeight.Bold,
+                            maxLines = 1,
+                            overflow = TextOverflow.Ellipsis,
+                        )
+                        Text(
+                            text = channel.toBestDisplayName(),
+                            style = MaterialTheme.typography.bodySmall,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            maxLines = 1,
+                            overflow = TextOverflow.Ellipsis,
+                        )
+                    }
+                },
+                popBack = nav::popBack,
+            )
+        },
+        floatingActionButton = {
+            FloatingActionButton(onClick = { showCompose = true }) {
+                Icon(
+                    symbol = MaterialSymbols.Add,
+                    contentDescription = stringRes(R.string.relay_group_thread_new),
+                    modifier = Modifier.size(24.dp),
+                )
+            }
+        },
+    ) { padding ->
+        if (threads.isEmpty()) {
+            Box(Modifier.fillMaxSize().padding(padding), contentAlignment = Alignment.Center) {
+                Text(
+                    text = stringRes(R.string.relay_group_threads_empty),
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier.padding(32.dp),
+                )
+            }
+        } else {
+            LazyColumn(modifier = Modifier.padding(padding)) {
+                items(threads, key = { it.idHex }) { thread ->
+                    ThreadRow(thread, accountViewModel, nav) { nav.nav(Route.Note(thread.idHex)) }
+                    HorizontalDivider(thickness = 0.25.dp, color = MaterialTheme.colorScheme.outlineVariant)
+                }
+            }
+        }
+    }
+
+    if (showCompose) {
+        NewRelayGroupThreadDialog(channel, accountViewModel) { showCompose = false }
+    }
+}
+
+@Composable
+private fun ThreadRow(
+    thread: Note,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+    onClick: () -> Unit,
+) {
+    val event = thread.event as? ThreadEvent
+    val title = event?.title()?.takeIf { it.isNotBlank() } ?: stringRes(R.string.relay_group_thread_untitled)
+    val preview =
+        event
+            ?.content
+            ?.replace('\n', ' ')
+            ?.trim()
+            .orEmpty()
+    val replyCount = thread.replies.size
+    val author = thread.author
+
+    Row(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clickable(onClick = onClick)
+                .padding(horizontal = 16.dp, vertical = 12.dp),
+        horizontalArrangement = Arrangement.spacedBy(12.dp),
+    ) {
+        if (author != null) {
+            UserPicture(author, Size35dp, accountViewModel = accountViewModel, nav = nav)
+        }
+        Column(Modifier.weight(1f)) {
+            Text(
+                text = title,
+                fontWeight = FontWeight.SemiBold,
+                maxLines = 2,
+                overflow = TextOverflow.Ellipsis,
+            )
+            if (preview.isNotEmpty()) {
+                Text(
+                    text = preview,
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                )
+            }
+            Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(4.dp)) {
+                if (author != null) {
+                    UsernameDisplay(author, accountViewModel = accountViewModel)
+                }
+                Icon(
+                    symbol = MaterialSymbols.Chat,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier.size(13.dp),
+                )
+                Text(
+                    text = "$replyCount",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/relayGroup/RelayGroupTopBar.kt

@@ -141,6 +141,16 @@ fun RelayGroupTopBar(
             }
         },
         actions = {
+            IconButton(onClick = {
+                nav.nav(Route.RelayGroupThreads(channel.groupId.id, channel.groupId.relayUrl.url))
+            }) {
+                Icon(
+                    symbol = MaterialSymbols.Forum,
+                    contentDescription = stringRes(R.string.relay_group_threads_title),
+                    modifier = Modifier.size(20.dp),
+                )
+            }
+
             val naddr = channel.toNAddr()
             if (naddr != null) {
                 val context = LocalContext.current

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/relayGroup/datasource/RelayGroupThreadsFilterAssembler.kt

@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.datasource
+
+import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupChannel
+import com.vitorpamplona.amethyst.commons.relayClient.composeSubscriptionManagers.ComposeSubscriptionManager
+import com.vitorpamplona.amethyst.service.relayClient.eoseManagers.PerUniqueIdEoseManager
+import com.vitorpamplona.amethyst.service.relays.SincePerRelayMap
+import com.vitorpamplona.quartz.nip01Core.relay.client.INostrClient
+import com.vitorpamplona.quartz.nip01Core.relay.client.pool.RelayBasedFilter
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip22Comments.CommentEvent
+import com.vitorpamplona.quartz.nip29RelayGroups.GroupId
+import com.vitorpamplona.quartz.nip7DThreads.ThreadEvent
+
+/** One threads-screen's request for a single group's kind-11 threads. */
+class RelayGroupThreadsQueryState(
+    val channel: RelayGroupChannel,
+)
+
+/**
+ * The forum content of a NIP-29 group: kind-11 thread roots plus their kind-1111
+ * comment trees, both scoped by the group's `h` tag and pinned to the host relay.
+ * Active only while a group's Threads screen is open (threads are secondary to the
+ * kind-9 chat, so we don't pay for them until asked). Fetching the comments here
+ * too means opening a thread from the list has its replies already cached.
+ */
+class RelayGroupThreadsFilterAssembler(
+    client: INostrClient,
+) : ComposeSubscriptionManager<RelayGroupThreadsQueryState>() {
+    val group =
+        listOf(
+            RelayGroupThreadsSubAssembler(client, ::allKeys),
+        )
+
+    override fun invalidateKeys() = invalidateFilters()
+
+    override fun invalidateFilters() = group.forEach { it.invalidateFilters() }
+
+    override fun destroy() = group.forEach { it.destroy() }
+}
+
+class RelayGroupThreadsSubAssembler(
+    client: INostrClient,
+    allKeys: () -> Set<RelayGroupThreadsQueryState>,
+) : PerUniqueIdEoseManager<RelayGroupThreadsQueryState, GroupId>(client, allKeys) {
+    override fun updateFilter(
+        key: RelayGroupThreadsQueryState,
+        since: SincePerRelayMap?,
+    ): List<RelayBasedFilter> {
+        val groupId = key.channel.groupId
+        return listOf(
+            RelayBasedFilter(
+                relay = groupId.relayUrl,
+                filter =
+                    Filter(
+                        kinds = listOf(ThreadEvent.KIND, CommentEvent.KIND),
+                        tags = mapOf("h" to listOf(groupId.id)),
+                        since = since?.get(groupId.relayUrl)?.time,
+                    ),
+            ),
+        )
+    }
+
+    override fun id(key: RelayGroupThreadsQueryState) = key.channel.groupId
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/relayGroup/datasource/RelayGroupThreadsSubscription.kt

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.datasource
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupChannel
+import com.vitorpamplona.amethyst.commons.relayClient.subscriptions.LifecycleAwareKeyDataSourceSubscription
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+
+/** Mount on a group's Threads screen to stream its kind-11 threads + 1111 comments. */
+@Composable
+fun RelayGroupThreadsSubscription(
+    channel: RelayGroupChannel,
+    dataSource: RelayGroupThreadsFilterAssembler,
+    accountViewModel: AccountViewModel,
+) {
+    val state =
+        remember(channel.groupId) {
+            RelayGroupThreadsQueryState(channel)
+        }
+
+    LifecycleAwareKeyDataSourceSubscription(state, dataSource)
+}

amethyst/src/main/res/values/strings.xml

@@ -1965,6 +1965,13 @@
     <string name="relay_group_edit_confirm">Save</string>
     <string name="relay_group_menu_members">Members</string>
     <string name="relay_group_menu_edit">Edit group</string>
+    <string name="relay_group_threads_title">Threads</string>
+    <string name="relay_group_threads_empty">No threads yet. Start one with the + button.</string>
+    <string name="relay_group_thread_new">New thread</string>
+    <string name="relay_group_thread_untitled">Untitled</string>
+    <string name="relay_group_thread_title_label">Title</string>
+    <string name="relay_group_thread_body_label">Write something…</string>
+    <string name="relay_group_thread_post">Post</string>
     <string name="relay_group_browse_title">Find groups</string>
     <string name="relay_group_browse_description">Browse the groups hosted on a relay. Paste a relay address, or pick one below.</string>
     <string name="relay_group_browse_relay_label">Relay address</string>

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/nip29RelayGroups/RelayGroupChannel.kt

@@ -30,6 +30,9 @@ import com.vitorpamplona.quartz.nip29RelayGroups.metadata.GroupAdminsEvent
 import com.vitorpamplona.quartz.nip29RelayGroups.metadata.GroupMembersEvent
 import com.vitorpamplona.quartz.nip29RelayGroups.metadata.GroupMetadataEvent
 import com.vitorpamplona.quartz.nip29RelayGroups.tags.GroupAdminTag
+import com.vitorpamplona.quartz.utils.cache.LargeCache
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
 
 /**
  * A NIP-29 relay-based group ("channel" in Discord terms). Unlike a NIP-C7
@@ -65,6 +68,31 @@ class RelayGroupChannel(
         private set
     private var adminsUpdatedAt: Long = 0
 
+    /**
+     * Kind-11 threads (forum-style posts) scoped to this group, kept apart from the
+     * kind-9 chat [Channel.notes] so the chat feed stays clean. Surfaced through the
+     * group's "Threads" view; each thread's own comment tree (kind 1111) is loaded
+     * on demand by the thread-detail screen.
+     */
+    private val threadNotes = LargeCache<HexKey, Note>()
+    private val _threads = MutableStateFlow<List<Note>>(emptyList())
+    val threads: StateFlow<List<Note>> = _threads
+
+    /** Add a kind-11 thread note; newest-first snapshot is re-published to [threads]. */
+    fun addThread(note: Note) {
+        if (threadNotes.containsKey(note.idHex)) return
+        threadNotes.put(note.idHex, note)
+        _threads.value = threadNotes.values().sortedByDescending { it.createdAt() ?: 0L }
+    }
+
+    fun removeThread(note: Note) {
+        if (!threadNotes.containsKey(note.idHex)) return
+        threadNotes.remove(note.idHex)
+        _threads.value = threadNotes.values().sortedByDescending { it.createdAt() ?: 0L }
+    }
+
+    fun threadCount(): Int = threadNotes.size()
+
     /** A relay group lives on exactly one relay: its host. */
     override fun relays() = setOf(groupId.relayUrl)
 

commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/nip29RelayGroups/RelayGroupChannelTest.kt

@@ -20,6 +20,7 @@
  */
 package com.vitorpamplona.amethyst.commons.model.nip29RelayGroups
 
+import com.vitorpamplona.amethyst.commons.model.Note
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
 import com.vitorpamplona.quartz.nip29RelayGroups.GroupId
 import com.vitorpamplona.quartz.nip29RelayGroups.metadata.GroupAdminsEvent
@@ -178,4 +179,23 @@ class RelayGroupChannelTest {
     fun displayNameFallsBackToGroupIdWithoutMetadata() {
         assertEquals(gid, channel().toBestDisplayName())
     }
+
+    @Test
+    fun threadsDedupePublishToFlowAndRemove() {
+        val c = channel()
+        val t1 = Note("11".repeat(32))
+        val t2 = Note("22".repeat(32))
+
+        c.addThread(t1)
+        c.addThread(t2)
+        c.addThread(t1) // duplicate id — must not double-count
+
+        assertEquals(2, c.threadCount())
+        assertEquals(2, c.threads.value.size)
+        assertTrue(c.threads.value.any { it.idHex == t1.idHex })
+
+        c.removeThread(t1)
+        assertEquals(1, c.threadCount())
+        assertTrue(c.threads.value.none { it.idHex == t1.idHex })
+    }
 }