feat(buzz): presence dots, collapsible sections + unread + stars, canvas editing, bot "Working…" indicator

Brings the Buzz community + member screens closer to Buzz's own clients:

- Presence dots (BuzzPresenceState → online green / away amber) overlaid
  on DM-row and member-list avatars; offline/unknown shows nothing rather
  than implying we track a peer we don't.
- Community view sections (Channels / Forums) are now collapsible, each
  channel row carries an unread dot (relayGroupChannelHasUnreadFlow) and a
  star toggle; starred channels float to the top. Stars persist
  device-globally (BuzzChannelStars + BuzzChannelStarPreferences), mirroring
  the joined-workspaces store.
- Canvas editing: the canvas screen gains an edit mode that publishes a
  fresh kind-40100 CanvasEvent to the channel's host relay (last-write-wins);
  the top-bar canvas button now shows on any Buzz channel so an empty one can
  be created.
- Bot "Working…" indicator: a process-wide BuzzAgentActivityState, fed by a
  members-screen observer (24200) subscription, lights a live "Working…" line
  next to an agent currently emitting frames; tapping opens the community's
  Agent Console. Owner-scoped by nature (frames are #p=owner).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J8KBSw6smQRyXLiWHeDsZ8

amethyst/src/main/java/com/vitorpamplona/amethyst/AppModules.kt

@@ -47,6 +47,7 @@ import com.vitorpamplona.amethyst.model.nip03Timestamp.IncomingOtsEventVerifier
 import com.vitorpamplona.amethyst.model.nip03Timestamp.TorAwareOkHttpOtsResolverBuilder
 import com.vitorpamplona.amethyst.model.nip11RelayInfo.Nip11CachedRetriever
 import com.vitorpamplona.amethyst.model.preferences.BuzzAttestationPreferences
+import com.vitorpamplona.amethyst.model.preferences.BuzzChannelStarPreferences
 import com.vitorpamplona.amethyst.model.preferences.BuzzWorkspacePreferences
 import com.vitorpamplona.amethyst.model.preferences.NamecoinSharedPreferences
 import com.vitorpamplona.amethyst.model.preferences.OtsSharedPreferences
@@ -281,6 +282,9 @@ class AppModules(
     // server-side; there is no join event to rebuild the set from).
     val buzzWorkspacePrefs = BuzzWorkspacePreferences(appContext, applicationIOScope)
 
+    // Restore + persist the user's starred Buzz workspace channels across restarts (device-global).
+    val buzzChannelStarPrefs = BuzzChannelStarPreferences(appContext, applicationIOScope)
+
     // Service that will run at all times to receive events from Pokey
     val pokeyReceiver = PokeyReceiver()
 

amethyst/src/main/java/com/vitorpamplona/amethyst/model/preferences/BuzzChannelStarPreferences.kt

@@ -0,0 +1,76 @@
+/*
+ * 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.model.preferences
+
+import android.content.Context
+import androidx.compose.runtime.Stable
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.stringSetPreferencesKey
+import com.vitorpamplona.amethyst.commons.model.buzz.BuzzChannelStars
+import com.vitorpamplona.quartz.utils.Log
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.drop
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.launch
+import kotlin.coroutines.cancellation.CancellationException
+
+/**
+ * Device-global persistence for the set of starred Buzz workspace channels ([BuzzChannelStars]),
+ * so favorites survive a restart. Mirrors [BuzzWorkspacePreferences]: app-wide (not per-account),
+ * loads the saved ids into the singleton on construction, then writes every later change back.
+ * Construct once, eagerly.
+ */
+@Stable
+class BuzzChannelStarPreferences(
+    private val context: Context,
+    private val scope: CoroutineScope,
+) {
+    init {
+        scope.launch {
+            restoreFromDisk()
+            // drop(1) skips the value present at collection start, which restoreFromDisk already wrote.
+            BuzzChannelStars.flow.drop(1).collect { persist(it) }
+        }
+    }
+
+    private suspend fun restoreFromDisk() {
+        try {
+            val raw = context.sharedPreferencesDataStore.data.first()[KEY] ?: return
+            if (raw.isNotEmpty()) BuzzChannelStars.restore(raw)
+        } catch (e: Exception) {
+            if (e is CancellationException) throw e
+            Log.e("BuzzChannelStarPrefs") { "Error reading starred channels: ${e.message}" }
+        }
+    }
+
+    private suspend fun persist(ids: Set<String>) {
+        try {
+            context.sharedPreferencesDataStore.edit { prefs -> prefs[KEY] = ids }
+        } catch (e: Exception) {
+            if (e is CancellationException) throw e
+            Log.e("BuzzChannelStarPrefs") { "Error writing starred channels: ${e.message}" }
+        }
+    }
+
+    companion object {
+        private val KEY = stringSetPreferencesKey("buzz.starredChannels")
+    }
+}

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

@@ -768,7 +768,7 @@ fun BuildNavigation(
                 nav = nav,
             )
         }
-        composableFromEndArgs<Route.BuzzCanvas> { BuzzCanvasScreen(it.channelId, accountViewModel, nav) }
+        composableFromEndArgs<Route.BuzzCanvas> { BuzzCanvasScreen(it.channelId, it.relayUrl, accountViewModel, nav) }
         composableFromBottomArgs<Route.BuzzForumPost> { BuzzForumPostScreen(it.channelId, it.relayUrl, accountViewModel, nav) }
         composableFromEndArgs<Route.BuzzForumThread> { BuzzForumThreadScreen(it.channelId, it.relayUrl, it.rootId, accountViewModel, nav) }
 

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

@@ -704,6 +704,7 @@ sealed class Route {
 
     @Serializable data class BuzzCanvas(
         val channelId: String,
+        val relayUrl: String,
     ) : Route()
 
     @Serializable data class BuzzForumPost(

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

@@ -20,18 +20,28 @@
  */
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz
 
+import androidx.activity.compose.BackHandler
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.text.selection.SelectionContainer
 import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.FloatingActionButton
+import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
@@ -39,6 +49,8 @@ import androidx.compose.ui.text.style.TextAlign
 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.EmptyTagList
 import com.vitorpamplona.amethyst.commons.model.buzz.BuzzWorkspaceStates
 import com.vitorpamplona.amethyst.ui.components.TranslatableRichTextViewer
@@ -46,17 +58,26 @@ import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.navigation.topbars.TopBarWithBackButton
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.quartz.buzz.stream.CanvasEvent
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 
 /**
- * Renders a Buzz workspace **canvas** (NIP kind 40100): the newest shared markdown
- * document for a channel. The canvas is overlay state held in [BuzzWorkspaceStates]
- * (never a timeline row — a workspace has one live canvas, last-write-wins), so this
- * reads the registry by the channel's `h` id and re-composes off `canvasUpdates` when a
- * newer revision lands.
+ * A Buzz workspace **canvas** (NIP kind 40100): the newest shared markdown document for a channel.
+ * The canvas is overlay state held in [BuzzWorkspaceStates] (never a timeline row — a workspace has
+ * one live canvas, last-write-wins), so this reads the registry by the channel's `h` id and
+ * re-composes off `canvasUpdates` when a newer revision lands.
+ *
+ * The edit FAB flips into a plain markdown editor; saving publishes a fresh [CanvasEvent] to the
+ * channel's host [relayUrl] (last-write-wins on the relay too), and the consume path folds the new
+ * revision back into [BuzzWorkspaceStates] so the view updates without a manual refresh.
  */
 @Composable
 fun BuzzCanvasScreen(
     channelId: String,
+    relayUrl: String,
     accountViewModel: AccountViewModel,
     nav: INav,
 ) {
@@ -66,8 +87,26 @@ fun BuzzCanvasScreen(
     val canvas = remember(version) { state.canvasNote }
     val content = canvas?.event?.content
 
+    var editing by remember { mutableStateOf(false) }
+
+    if (editing) {
+        CanvasEditor(
+            channelId = channelId,
+            relayUrl = relayUrl,
+            initial = content.orEmpty(),
+            accountViewModel = accountViewModel,
+            onClose = { editing = false },
+        )
+        return
+    }
+
     Scaffold(
         topBar = { TopBarWithBackButton(stringRes(R.string.buzz_canvas_title), nav) },
+        floatingActionButton = {
+            FloatingActionButton(onClick = { editing = true }) {
+                Icon(symbol = MaterialSymbols.Edit, contentDescription = stringRes(R.string.buzz_canvas_edit))
+            }
+        },
     ) { padding ->
         if (content.isNullOrBlank() || canvas == null) {
             Box(
@@ -109,3 +148,85 @@ fun BuzzCanvasScreen(
         }
     }
 }
+
+/** The markdown editor: a full-height text field for the canvas body with a Save action. */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun CanvasEditor(
+    channelId: String,
+    relayUrl: String,
+    initial: String,
+    accountViewModel: AccountViewModel,
+    onClose: () -> Unit,
+) {
+    var text by remember { mutableStateOf(initial) }
+    var saving by remember { mutableStateOf(false) }
+    var error by remember { mutableStateOf<String?>(null) }
+    val scope = rememberCoroutineScope()
+
+    // Back cancels the edit and returns to the rendered canvas rather than leaving the screen.
+    BackHandler(enabled = !saving, onBack = onClose)
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text(stringRes(R.string.buzz_canvas_edit)) },
+                navigationIcon = {
+                    IconButton(onClick = onClose, enabled = !saving) {
+                        Icon(symbol = MaterialSymbols.Close, contentDescription = stringRes(R.string.cancel))
+                    }
+                },
+            )
+        },
+        floatingActionButton = {
+            FloatingActionButton(
+                onClick = {
+                    val relay =
+                        RelayUrlNormalizer.normalizeOrNull(relayUrl) ?: run {
+                            error = "Invalid relay url"
+                            return@FloatingActionButton
+                        }
+                    saving = true
+                    error = null
+                    scope.launch {
+                        try {
+                            withContext(Dispatchers.IO) {
+                                accountViewModel.account.signAndSendPrivatelyOrBroadcast(
+                                    CanvasEvent.build(channelId, text),
+                                ) { listOf(relay) }
+                            }
+                            onClose()
+                        } catch (e: Exception) {
+                            saving = false
+                            error = "Failed to save: ${e.message ?: e::class.simpleName}"
+                        }
+                    }
+                },
+            ) {
+                if (saving) {
+                    CircularProgressIndicator(modifier = Modifier.padding(14.dp), strokeWidth = 2.dp)
+                } else {
+                    Icon(symbol = MaterialSymbols.Check, contentDescription = stringRes(R.string.buzz_canvas_save))
+                }
+            }
+        },
+    ) { padding ->
+        Box(Modifier.padding(padding).fillMaxSize().padding(16.dp)) {
+            OutlinedTextField(
+                value = text,
+                onValueChange = {
+                    text = it
+                    error = null
+                },
+                modifier = Modifier.fillMaxSize(),
+                enabled = !saving,
+                label = { Text(stringRes(R.string.buzz_canvas_body_label)) },
+            )
+            error?.let {
+                SelectionContainer(Modifier.align(Alignment.BottomStart)) {
+                    Text(it, color = MaterialTheme.colorScheme.error, style = MaterialTheme.typography.bodySmall)
+                }
+            }
+        }
+    }
+}

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

@@ -31,6 +31,7 @@ import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material3.Card
+import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.Text
@@ -44,6 +45,7 @@ import androidx.compose.ui.graphics.Color
 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
@@ -51,6 +53,7 @@ import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupChann
 import com.vitorpamplona.amethyst.model.LocalCache
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.channel.observeChannel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.relayGroupChannelHasUnreadFlow
 import com.vitorpamplona.amethyst.ui.stringRes
 import com.vitorpamplona.quartz.nip29RelayGroups.GroupId
 
@@ -67,6 +70,8 @@ fun BuzzImportRow(
     onAdd: () -> Unit,
     accountViewModel: AccountViewModel,
     onOpen: (() -> Unit)? = null,
+    isStarred: Boolean = false,
+    onToggleStar: (() -> Unit)? = null,
 ) {
     val baseChannel = remember(groupId) { LocalCache.getOrCreateRelayGroupChannel(groupId) }
     val channelState by observeChannel(baseChannel, accountViewModel)
@@ -75,14 +80,19 @@ fun BuzzImportRow(
     val name = channel.toBestDisplayName()
     val memberCount = channel.memberCount()
 
+    // An unread dot when this group has chat newer than the last time this account opened it.
+    val hasUnread by remember(groupId) {
+        relayGroupChannelHasUnreadFlow(accountViewModel.account, groupId)
+    }.collectAsStateWithLifecycle(false)
+
+    val content =
+        @Composable {
+            BuzzImportRowContent(name, groupId.id, memberCount, isAdded, hasUnread, isStarred, onToggleStar, onAdd)
+        }
     if (onOpen != null) {
-        Card(onClick = onOpen, modifier = Modifier.fillMaxWidth()) {
-            BuzzImportRowContent(name, groupId.id, memberCount, isAdded, onAdd)
-        }
+        Card(onClick = onOpen, modifier = Modifier.fillMaxWidth()) { content() }
     } else {
-        Card(modifier = Modifier.fillMaxWidth()) {
-            BuzzImportRowContent(name, groupId.id, memberCount, isAdded, onAdd)
-        }
+        Card(modifier = Modifier.fillMaxWidth()) { content() }
     }
 }
 
@@ -92,19 +102,36 @@ private fun BuzzImportRowContent(
     seed: String,
     memberCount: Int,
     isAdded: Boolean,
+    hasUnread: Boolean,
+    isStarred: Boolean,
+    onToggleStar: (() -> Unit)?,
     onAdd: () -> Unit,
 ) {
     Row(
-        modifier = Modifier.padding(12.dp),
+        modifier = Modifier.padding(start = 12.dp, top = 8.dp, bottom = 8.dp, end = 4.dp),
         verticalAlignment = Alignment.CenterVertically,
     ) {
-        BuzzImportAvatar(name = name, seed = seed)
+        Box {
+            BuzzImportAvatar(name = name, seed = seed)
+            if (hasUnread) {
+                Box(
+                    Modifier
+                        .align(Alignment.TopEnd)
+                        .size(11.dp)
+                        .clip(CircleShape)
+                        .background(MaterialTheme.colorScheme.surface)
+                        .padding(2.dp)
+                        .clip(CircleShape)
+                        .background(MaterialTheme.colorScheme.primary),
+                )
+            }
+        }
         Spacer(Modifier.width(12.dp))
         Column(modifier = Modifier.weight(1f)) {
             Text(
                 text = name,
                 style = MaterialTheme.typography.titleSmall,
-                fontWeight = FontWeight.Bold,
+                fontWeight = if (hasUnread) FontWeight.Bold else FontWeight.SemiBold,
                 maxLines = 1,
                 overflow = TextOverflow.Ellipsis,
             )
@@ -116,6 +143,16 @@ private fun BuzzImportRowContent(
                 )
             }
         }
+        if (onToggleStar != null) {
+            IconButton(onClick = onToggleStar) {
+                Icon(
+                    symbol = if (isStarred) MaterialSymbols.Star else MaterialSymbols.StarBorder,
+                    contentDescription = stringRes(if (isStarred) R.string.buzz_unstar else R.string.buzz_star),
+                    tint = if (isStarred) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier.size(20.dp),
+                )
+            }
+        }
         if (isAdded) {
             Row(verticalAlignment = Alignment.CenterVertically) {
                 Icon(

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

@@ -0,0 +1,78 @@
+/*
+ * 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.buzz
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.vitorpamplona.amethyst.commons.model.buzz.BuzzPresenceState
+import com.vitorpamplona.quartz.buzz.presence.PresenceStatus
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+
+private val PresenceOnline = Color(0xFF4CAF50)
+private val PresenceAway = Color(0xFFFFB300)
+
+/** The latest Buzz presence for [pubkey], mapped to the curated enum, or null when none is known. */
+@Composable
+fun rememberBuzzPresence(pubkey: HexKey): PresenceStatus? {
+    val map by BuzzPresenceState.flow.collectAsStateWithLifecycle()
+    return remember(map, pubkey) { map[pubkey]?.let { PresenceStatus.fromWire(it) } }
+}
+
+/**
+ * A small status dot for a Buzz workspace member — green online, amber away — rendered nowhere for
+ * offline/unknown so the UI doesn't imply presence tracking where there is none. Meant to be
+ * overlaid on the bottom-end of an avatar inside a [Box] (pass `Modifier.align(...)`).
+ */
+@Composable
+fun PresenceDot(
+    pubkey: HexKey,
+    modifier: Modifier = Modifier,
+    size: Dp = 11.dp,
+    ringColor: Color = Color.Unspecified,
+) {
+    val color =
+        when (rememberBuzzPresence(pubkey)) {
+            PresenceStatus.ONLINE -> PresenceOnline
+            PresenceStatus.AWAY -> PresenceAway
+            // Offline / unknown: render nothing rather than a grey dot implying we track them.
+            else -> return
+        }
+    Box(
+        modifier =
+            modifier
+                .size(size)
+                .clip(CircleShape)
+                .then(if (ringColor != Color.Unspecified) Modifier.border(2.dp, ringColor, CircleShape) else Modifier)
+                .background(color, CircleShape),
+    )
+}

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

@@ -54,6 +54,7 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.draw.rotate
 import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextOverflow
@@ -64,6 +65,7 @@ import com.vitorpamplona.amethyst.Amethyst
 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.buzz.BuzzChannelStars
 import com.vitorpamplona.amethyst.commons.model.buzz.BuzzRelayDialect
 import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupChannel
 import com.vitorpamplona.amethyst.commons.tor.TorType
@@ -83,6 +85,7 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.BuzzDmListViewModel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.BuzzImportRow
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.BuzzRelayImportViewModel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.PresenceDot
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.datasource.RelayGroupCardWarmupSubscription
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.datasource.RelayGroupsOnRelaySubscription
 import com.vitorpamplona.amethyst.ui.stringRes
@@ -207,15 +210,29 @@ fun RelayGroupChannelListScreen(
         }
 
     fun buzzTypeOf(groupId: GroupId): String? = channelsById[groupId.id]?.event?.buzzChannelType()
+    // Starred channels float to the top of their section (stable sort keeps the alphabetical order
+    // within the starred and unstarred buckets).
+    val starred by BuzzChannelStars.flow.collectAsStateWithLifecycle()
     val buzzChatChannels =
-        remember(buzzGroupIds, channelsById) {
-            buzzGroupIds.filter { buzzTypeOf(it).let { t -> t != BUZZ_CHANNEL_TYPE_FORUM && t != BUZZ_CHANNEL_TYPE_DM } }
+        remember(buzzGroupIds, channelsById, starred) {
+            buzzGroupIds
+                .filter { buzzTypeOf(it).let { t -> t != BUZZ_CHANNEL_TYPE_FORUM && t != BUZZ_CHANNEL_TYPE_DM } }
+                .sortedByDescending { it.id in starred }
         }
     val buzzForumChannels =
-        remember(buzzGroupIds, channelsById) {
-            buzzGroupIds.filter { buzzTypeOf(it) == BUZZ_CHANNEL_TYPE_FORUM }
+        remember(buzzGroupIds, channelsById, starred) {
+            buzzGroupIds
+                .filter { buzzTypeOf(it) == BUZZ_CHANNEL_TYPE_FORUM }
+                .sortedByDescending { it.id in starred }
         }
 
+    // Which sections the user has collapsed (session-scoped). Keyed by section id below.
+    var collapsedSections by remember { mutableStateOf(emptySet<String>()) }
+
+    fun toggleSection(key: String) {
+        collapsedSections = if (key in collapsedSections) collapsedSections - key else collapsedSections + key
+    }
+
     // Tor-failure escape hatch: a Cloudflare-fronted (or otherwise Tor-hostile) relay times out over
     // Tor. When Tor is on, the relay isn't an onion, it isn't already trusted, and nothing has loaded
     // after a grace period, offer to reach it over clearnet — which adds it to the kind-10089 Trusted
@@ -313,8 +330,13 @@ fun RelayGroupChannelListScreen(
 
                     // -- CHANNELS --
                     if (buzzChatChannels.isNotEmpty()) {
+                        val channelsCollapsed = "channels" in collapsedSections
                         item(key = "sec-channels") {
-                            RelayGroupSectionHeader(title = stringRes(R.string.relay_group_section_channels)) {
+                            RelayGroupSectionHeader(
+                                title = stringRes(R.string.relay_group_section_channels),
+                                collapsed = channelsCollapsed,
+                                onToggle = { toggleSection("channels") },
+                            ) {
                                 if (buzzChatChannels.any { it.id !in buzzAdded }) {
                                     FilledTonalButton(onClick = { buzzVm.addAll() }) {
                                         Text(stringRes(R.string.buzz_import_add_all))
@@ -322,33 +344,46 @@ fun RelayGroupChannelListScreen(
                                 }
                             }
                         }
-                        items(buzzChatChannels, key = { "chat-${it.id}" }) { groupId ->
-                            BuzzImportRow(
-                                groupId = groupId,
-                                isAdded = groupId.id in buzzAdded,
-                                onAdd = { buzzVm.add(groupId) },
-                                accountViewModel = accountViewModel,
-                                onOpen = { nav.nav(Route.RelayGroup(groupId.id, relay.url)) },
-                            )
+                        if (!channelsCollapsed) {
+                            items(buzzChatChannels, key = { "chat-${it.id}" }) { groupId ->
+                                BuzzImportRow(
+                                    groupId = groupId,
+                                    isAdded = groupId.id in buzzAdded,
+                                    onAdd = { buzzVm.add(groupId) },
+                                    accountViewModel = accountViewModel,
+                                    onOpen = { nav.nav(Route.RelayGroup(groupId.id, relay.url)) },
+                                    isStarred = groupId.id in starred,
+                                    onToggleStar = { BuzzChannelStars.toggle(groupId.id) },
+                                )
+                            }
                         }
                     }
 
                     // -- FORUMS --
                     if (buzzForumChannels.isNotEmpty()) {
+                        val forumsCollapsed = "forums" in collapsedSections
                         item(key = "sec-forums") {
-                            RelayGroupSectionHeader(title = stringRes(R.string.relay_group_section_forums))
-                        }
-                        items(buzzForumChannels, key = { "forum-${it.id}" }) { groupId ->
-                            BuzzImportRow(
-                                groupId = groupId,
-                                isAdded = groupId.id in buzzAdded,
-                                onAdd = { buzzVm.add(groupId) },
-                                accountViewModel = accountViewModel,
-                                // A forum channel's primary content is its threads (kind-45001 posts), not a
-                                // kind-9 chat, so open the forum/threads view directly instead of the chat.
-                                onOpen = { nav.nav(Route.RelayGroupThreads(groupId.id, relay.url)) },
+                            RelayGroupSectionHeader(
+                                title = stringRes(R.string.relay_group_section_forums),
+                                collapsed = forumsCollapsed,
+                                onToggle = { toggleSection("forums") },
                             )
                         }
+                        if (!forumsCollapsed) {
+                            items(buzzForumChannels, key = { "forum-${it.id}" }) { groupId ->
+                                BuzzImportRow(
+                                    groupId = groupId,
+                                    isAdded = groupId.id in buzzAdded,
+                                    onAdd = { buzzVm.add(groupId) },
+                                    accountViewModel = accountViewModel,
+                                    // A forum channel's primary content is its threads (kind-45001 posts), not a
+                                    // kind-9 chat, so open the forum/threads view directly instead of the chat.
+                                    onOpen = { nav.nav(Route.RelayGroupThreads(groupId.id, relay.url)) },
+                                    isStarred = groupId.id in starred,
+                                    onToggleStar = { BuzzChannelStars.toggle(groupId.id) },
+                                )
+                            }
+                        }
                     }
 
                     // -- DIRECT MESSAGES -- (this community's private conversations, most recent first)
@@ -452,12 +487,28 @@ private fun TorClearnetBanner(
 @Composable
 private fun RelayGroupSectionHeader(
     title: String,
+    collapsed: Boolean = false,
+    onToggle: (() -> Unit)? = null,
     trailing: @Composable (() -> Unit)? = null,
 ) {
     Row(
-        modifier = Modifier.fillMaxWidth().padding(start = 16.dp, end = 8.dp, top = 18.dp, bottom = 4.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .then(if (onToggle != null) Modifier.clickable(onClick = onToggle) else Modifier)
+                .padding(start = 16.dp, end = 8.dp, top = 18.dp, bottom = 4.dp),
         verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(4.dp),
     ) {
+        if (onToggle != null) {
+            // A single chevron rotated 90° when expanded, so no extra glyph is needed.
+            Icon(
+                symbol = MaterialSymbols.ChevronRight,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.primary,
+                modifier = Modifier.size(18.dp).rotate(if (collapsed) 0f else 90f),
+            )
+        }
         Text(
             text = title,
             style = MaterialTheme.typography.labelLarge,
@@ -497,7 +548,13 @@ private fun BuzzDmInlineRow(
         verticalAlignment = Alignment.CenterVertically,
         horizontalArrangement = Arrangement.spacedBy(12.dp),
     ) {
-        UserPicture(leadHex, 40.dp, accountViewModel = accountViewModel, nav = nav)
+        // Only show a presence dot for a 1:1 DM — a cluster avatar can't carry one peer's status.
+        Box {
+            UserPicture(leadHex, 40.dp, accountViewModel = accountViewModel, nav = nav)
+            if (others.size == 1) {
+                PresenceDot(leadHex, Modifier.align(Alignment.BottomEnd), ringColor = MaterialTheme.colorScheme.surface)
+            }
+        }
         Text(
             text = label,
             style = MaterialTheme.typography.bodyLarge,

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

@@ -20,6 +20,8 @@
  */
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup
 
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -30,6 +32,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.itemsIndexed
+import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.CircularProgressIndicator
@@ -43,32 +46,45 @@ import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableLongStateOf
 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.draw.clip
 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.buzz.BuzzAgentActivityState
+import com.vitorpamplona.amethyst.commons.model.buzz.BuzzRelayDialect
 import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupChannel
 import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupMembership
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.channel.observeChannel
 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.buzz.PresenceDot
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.datasource.RelayGroupCardWarmupSubscription
 import com.vitorpamplona.amethyst.ui.stringRes
 import com.vitorpamplona.amethyst.ui.theme.Size35dp
+import com.vitorpamplona.quartz.buzz.aoObserver.ObserverFrameEvent
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.relay.client.reqs.subscribeAsFlow
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
 import com.vitorpamplona.quartz.nip29RelayGroups.GroupId
+import com.vitorpamplona.quartz.utils.TimeUtils
+import kotlinx.coroutines.delay
 
 /**
  * The roster of a NIP-29 group: everyone the relay lists as an admin (kind 39001)
@@ -121,6 +137,21 @@ private fun RelayGroupMembers(
     val iCanModerate = channel.membershipOf(myPubkey).canModerate()
     val iAmAdmin = channel.membershipOf(myPubkey) == RelayGroupMembership.ADMIN
 
+    // Feed the process-wide agent-activity state while this screen is open so a "Working…" line
+    // can light up next to an agent that's currently running. Observer frames (24200) are
+    // ephemeral and `#p`-addressed to the owner, so only the owner ever sees them — a non-owner
+    // simply never records anything and no indicator shows. Buzz relays only.
+    val relay = channel.groupId.relayUrl
+    LaunchedEffect(relay, myPubkey) {
+        if (!BuzzRelayDialect.isBuzz(relay)) return@LaunchedEffect
+        val filter = Filter(kinds = listOf(ObserverFrameEvent.KIND), tags = mapOf("p" to listOf(myPubkey)))
+        accountViewModel.account.client.subscribeAsFlow(relay, filter).collect { events ->
+            events.filterIsInstance<ObserverFrameEvent>().forEach { frame ->
+                BuzzAgentActivityState.record(frame.agentPubKey() ?: frame.pubKey, frame.createdAt)
+            }
+        }
+    }
+
     // Admins/moderators first, then plain members; alphabetical only inside a rank
     // is overkill here — rely on relay order but push elevated roles to the top.
     val roster =
@@ -216,7 +247,10 @@ private fun RelayGroupMemberRow(
         verticalAlignment = Alignment.CenterVertically,
         horizontalArrangement = Arrangement.spacedBy(12.dp),
     ) {
-        UserPicture(entry.pubkey, Size35dp, accountViewModel = accountViewModel, nav = nav)
+        Box {
+            UserPicture(entry.pubkey, Size35dp, accountViewModel = accountViewModel, nav = nav)
+            PresenceDot(entry.pubkey, Modifier.align(Alignment.BottomEnd), ringColor = MaterialTheme.colorScheme.surface)
+        }
 
         Column(Modifier.weight(1f)) {
             if (user != null) {
@@ -229,6 +263,9 @@ private fun RelayGroupMemberRow(
                     overflow = TextOverflow.Ellipsis,
                 )
             }
+            // A live "Working…" line for an agent member currently emitting observer frames;
+            // tapping it opens this community's Agent Console (Observer tab).
+            BotWorkingLabel(entry.pubkey) { nav.nav(Route.AgentConsole(channel.groupId.relayUrl.url)) }
         }
 
         MemberRoleBadge(entry)
@@ -350,6 +387,45 @@ private fun RelayGroupMemberRow(
     }
 }
 
+/** How recent an observer frame must be for an agent to read as "Working…" right now. */
+private const val BOT_WORKING_WINDOW_SECS = 90L
+
+/**
+ * A live "Working…" line shown for an agent member that emitted an observer frame within the last
+ * [BOT_WORKING_WINDOW_SECS]. Renders nothing for a normal member (no frames) or a stale agent, and
+ * re-checks freshness on a slow tick so it fades out when the agent goes quiet.
+ */
+@Composable
+private fun BotWorkingLabel(
+    agent: HexKey,
+    onClick: () -> Unit,
+) {
+    val activity by BuzzAgentActivityState.flow.collectAsStateWithLifecycle()
+    val last = activity[agent] ?: return
+
+    var nowSecs by remember { mutableLongStateOf(TimeUtils.now()) }
+    LaunchedEffect(agent) {
+        while (true) {
+            nowSecs = TimeUtils.now()
+            delay(4_000)
+        }
+    }
+    if (nowSecs - last > BOT_WORKING_WINDOW_SECS) return
+
+    Row(
+        modifier = Modifier.clickable(onClick = onClick),
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(5.dp),
+    ) {
+        Box(Modifier.size(6.dp).clip(CircleShape).background(MaterialTheme.colorScheme.primary))
+        Text(
+            text = stringRes(R.string.buzz_agent_working),
+            style = MaterialTheme.typography.labelSmall,
+            color = MaterialTheme.colorScheme.primary,
+        )
+    }
+}
+
 /**
  * A small colored pill for an elevated role; plain members get nothing.
  *

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

@@ -37,7 +37,6 @@ import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
-import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -52,7 +51,6 @@ 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.buzz.BuzzRelayDialect
-import com.vitorpamplona.amethyst.commons.model.buzz.BuzzWorkspaceStates
 import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupChannel
 import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupMembership
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.channel.observeChannel
@@ -167,21 +165,15 @@ fun RelayGroupTopBar(
                 )
             }
 
-            // Buzz workspace canvas (kind 40100): shown only on a Buzz-dialect relay once
-            // a canvas has arrived for this channel. Observing canvasUpdates flips it on
-            // the moment the first canvas is consumed, without swapping the channel object.
+            // Buzz workspace canvas (kind 40100): shown on any Buzz-dialect relay so a member can
+            // open the shared markdown doc — or create one when the channel has none yet.
             if (BuzzRelayDialect.isBuzz(channel.groupId.relayUrl)) {
-                val canvasState = remember(channel.groupId.id) { BuzzWorkspaceStates.getOrCreate(channel.groupId.id) }
-                val canvasVersion by canvasState.canvasUpdates.collectAsState()
-                val hasCanvas = remember(canvasVersion) { canvasState.canvasNote != null }
-                if (hasCanvas) {
-                    IconButton(onClick = { nav.nav(Route.BuzzCanvas(channel.groupId.id)) }) {
-                        Icon(
-                            symbol = MaterialSymbols.Dashboard,
-                            contentDescription = stringRes(R.string.buzz_canvas_title),
-                            modifier = Modifier.size(20.dp),
-                        )
-                    }
+                IconButton(onClick = { nav.nav(Route.BuzzCanvas(channel.groupId.id, channel.groupId.relayUrl.url)) }) {
+                    Icon(
+                        symbol = MaterialSymbols.Dashboard,
+                        contentDescription = stringRes(R.string.buzz_canvas_title),
+                        modifier = Modifier.size(20.dp),
+                    )
                 }
             }
 

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

@@ -3305,6 +3305,9 @@
     <string name="buzz_diff_truncated">(diff truncated)</string>
     <string name="buzz_canvas_title">Canvas</string>
     <string name="buzz_canvas_empty">No canvas has been shared in this workspace yet.</string>
+    <string name="buzz_canvas_edit">Edit canvas</string>
+    <string name="buzz_canvas_save">Save canvas</string>
+    <string name="buzz_canvas_body_label">Canvas (Markdown)</string>
     <string name="buzz_edit_message">Edit</string>
     <string name="buzz_editing_banner">Editing message</string>
     <string name="buzz_typing_one">%1$s is typing…</string>
@@ -3362,6 +3365,9 @@
 
     <string name="relay_group_section_channels">Channels</string>
     <string name="relay_group_section_forums">Forums</string>
+    <string name="buzz_agent_working">Working…</string>
+    <string name="buzz_star">Star channel</string>
+    <string name="buzz_unstar">Unstar channel</string>
     <string name="buzz_dm_section_empty">No conversations yet</string>
     <plurals name="buzz_dm_see_all_count">
         <item quantity="one">See %1$d more conversation</item>

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/buzz/BuzzAgentActivityState.kt

@@ -0,0 +1,65 @@
+/*
+ * 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.commons.model.buzz
+
+import com.vitorpamplona.amethyst.commons.util.KmpLock
+import com.vitorpamplona.amethyst.commons.util.withLock
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * Live "an agent is currently working" state for Buzz workspaces, fed by the ephemeral NIP-AO
+ * observer frames (kind-24200, `#p` = owner). Frames stream in only while an agent is actively
+ * running and only reach the owner, so the mere arrival of a recent frame — no decryption needed —
+ * is the liveness signal a "Working…" indicator wants.
+ *
+ * Shape: `agentPubKey -> the newest frame time (secs)`. The display edge decides how fresh counts
+ * as "working" (a short window), since ephemeral frames are frequent while active and simply stop
+ * when the turn ends. Process-wide singleton like [BuzzTypingState] / [BuzzPresenceState]; mutations
+ * are lock-guarded because relay reads land on several reader threads.
+ */
+object BuzzAgentActivityState {
+    private val lock = KmpLock()
+    private val lastFrameSecs = HashMap<HexKey, Long>()
+    private val mutableActivity = MutableStateFlow<Map<HexKey, Long>>(emptyMap())
+
+    /** `agentPubKey -> newest observer-frame time (secs)`; the UI collects this and checks freshness. */
+    val flow: StateFlow<Map<HexKey, Long>> = mutableActivity
+
+    /** Records that [agent] emitted a frame at [atSecs]; keeps the newest so staleness is monotonic. */
+    fun record(
+        agent: HexKey,
+        atSecs: Long,
+    ) = lock.withLock {
+        val prev = lastFrameSecs[agent]
+        if (prev != null && atSecs <= prev) return@withLock
+        lastFrameSecs[agent] = atSecs
+        mutableActivity.value = lastFrameSecs.toMap()
+    }
+
+    /** Test-only: clears all activity so unit tests don't leak into each other. */
+    fun clearForTesting() =
+        lock.withLock {
+            lastFrameSecs.clear()
+            mutableActivity.value = emptyMap()
+        }
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/buzz/BuzzChannelStars.kt

@@ -0,0 +1,60 @@
+/*
+ * 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.commons.model.buzz
+
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * The set of Buzz workspace channels the user has **starred** (favorited), keyed by channel id (the
+ * NIP-29 `h`/UUID, globally unique on Buzz). Starred channels float to the top of the community view.
+ *
+ * There is no Nostr event for a personal star — it's the client's own bookkeeping — so, like
+ * [BuzzWorkspaces], this is a process-wide singleton mirrored to a device-global store by the
+ * platform ([com.vitorpamplona.amethyst] `BuzzChannelStarPreferences`) and restored at startup.
+ */
+object BuzzChannelStars {
+    private val starred = MutableStateFlow<Set<String>>(emptySet())
+
+    /** The starred channel ids; the community view collects this to pin + badge them. */
+    val flow: StateFlow<Set<String>> = starred
+
+    fun isStarred(channelId: String): Boolean = channelId in starred.value
+
+    /** Flips [channelId]'s star. Returns the new state (true = now starred). */
+    fun toggle(channelId: String): Boolean {
+        while (true) {
+            val current = starred.value
+            val next = if (channelId in current) current - channelId else current + channelId
+            if (starred.compareAndSet(current, next)) return channelId in next
+        }
+    }
+
+    /** Replaces the whole set — used to restore from disk at startup. */
+    fun restore(ids: Set<String>) {
+        starred.value = ids
+    }
+
+    /** Test-only: clears the set so unit tests don't leak state into each other. */
+    fun clearForTesting() {
+        starred.value = emptySet()
+    }
+}