feat(chess): add platform adapters and enhance lobby state (steps 5-6)

- Add ChessLobbyState with completedGames, replaceGameState(), moveToCompleted()
- Add challengerAvatarUrl to ChessChallenge
- Add CompletedGame data class for game history

Platform Adapters:
- AndroidChessAdapter: AndroidChessPublisher, AndroidRelayFetcher, AndroidMetadataProvider
- DesktopChessAdapter: DesktopChessPublisher, DesktopRelayFetcher, DesktopMetadataProvider

Shared Infrastructure:
- ChessRelayFetchHelper for one-shot relay queries
- IUserMetadataProvider interface for platform-specific metadata
- ChessFilterBuilder with simple filter methods for fetchers
- ChessSubscriptionController interface for subscription management

Fix ChessSubscription.kt to remove broken dataSources().chess reference
(subscriptions now managed by ChessLobbyLogic)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

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

@@ -168,11 +168,6 @@ import com.vitorpamplona.quartz.nip58Badges.BadgeProfilesEvent
 import com.vitorpamplona.quartz.nip59Giftwrap.WrappedEvent
 import com.vitorpamplona.quartz.nip59Giftwrap.seals.SealedRumorEvent
 import com.vitorpamplona.quartz.nip59Giftwrap.wraps.GiftWrapEvent
-import com.vitorpamplona.quartz.nip64Chess.ChessGameEvent
-import com.vitorpamplona.quartz.nip64Chess.LiveChessGameAcceptEvent
-import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
-import com.vitorpamplona.quartz.nip64Chess.LiveChessGameEndEvent
-import com.vitorpamplona.quartz.nip64Chess.LiveChessMoveEvent
 import com.vitorpamplona.quartz.nip65RelayList.AdvertisedRelayListEvent
 import com.vitorpamplona.quartz.nip68Picture.PictureEvent
 import com.vitorpamplona.quartz.nip71Video.VideoHorizontalEvent
@@ -604,36 +599,6 @@ object LocalCache : ILocalCache, ICacheProvider {
         wasVerified: Boolean,
     ) = consumeBaseReplaceable(event, relay, wasVerified)
 
-    fun consume(
-        event: ChessGameEvent,
-        relay: NormalizedRelayUrl?,
-        wasVerified: Boolean,
-    ) = consumeRegularEvent(event, relay, wasVerified)
-
-    fun consume(
-        event: LiveChessGameChallengeEvent,
-        relay: NormalizedRelayUrl?,
-        wasVerified: Boolean,
-    ) = consumeRegularEvent(event, relay, wasVerified)
-
-    fun consume(
-        event: LiveChessGameAcceptEvent,
-        relay: NormalizedRelayUrl?,
-        wasVerified: Boolean,
-    ) = consumeRegularEvent(event, relay, wasVerified)
-
-    fun consume(
-        event: LiveChessMoveEvent,
-        relay: NormalizedRelayUrl?,
-        wasVerified: Boolean,
-    ) = consumeRegularEvent(event, relay, wasVerified)
-
-    fun consume(
-        event: LiveChessGameEndEvent,
-        relay: NormalizedRelayUrl?,
-        wasVerified: Boolean,
-    ) = consumeRegularEvent(event, relay, wasVerified)
-
     fun consumeRegularEvent(
         event: Event,
         relay: NormalizedRelayUrl?,
@@ -2965,11 +2930,6 @@ object LocalCache : ILocalCache, ICacheProvider {
                 is CalendarDateSlotEvent -> consume(event, relay, wasVerified)
                 is CalendarTimeSlotEvent -> consume(event, relay, wasVerified)
                 is CalendarRSVPEvent -> consume(event, relay, wasVerified)
-                is ChessGameEvent -> consume(event, relay, wasVerified)
-                is LiveChessGameChallengeEvent -> consume(event, relay, wasVerified)
-                is LiveChessGameAcceptEvent -> consume(event, relay, wasVerified)
-                is LiveChessMoveEvent -> consume(event, relay, wasVerified)
-                is LiveChessGameEndEvent -> consume(event, relay, wasVerified)
                 is ChannelCreateEvent -> consume(event, relay, wasVerified)
                 is ChannelListEvent -> consume(event, relay, wasVerified)
                 is ChannelHideMessageEvent -> consume(event, relay, wasVerified)

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

@@ -31,7 +31,6 @@ import com.vitorpamplona.amethyst.service.relayClient.searchCommand.SearchFilter
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.privateDM.datasource.ChatroomFilterAssembler
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.datasource.ChannelFilterAssembler
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.rooms.datasource.ChatroomListFilterAssembler
-import com.vitorpamplona.amethyst.ui.screen.loggedIn.chess.ChessFilterAssembler
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.communities.datasource.CommunityFilterAssembler
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.discover.datasource.DiscoveryFilterAssembler
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.followPacks.feed.datasource.FollowPackFeedFilterAssembler
@@ -80,7 +79,6 @@ class RelaySubscriptionsCoordinator(
     val hashtags = HashtagFilterAssembler(client)
     val geohashes = GeoHashFilterAssembler(client)
     val followPacks = FollowPackFeedFilterAssembler(client)
-    val chess = ChessFilterAssembler(client)
 
     // active when sending zaps via NWC
     val nwc = NWCPaymentFilterAssembler(client)
@@ -103,7 +101,6 @@ class RelaySubscriptionsCoordinator(
             profile,
             hashtags,
             geohashes,
-            chess,
             nwc,
         )
 

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

@@ -0,0 +1,251 @@
+/**
+ * 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.chess
+
+import com.vitorpamplona.amethyst.commons.chess.ChessEventPublisher
+import com.vitorpamplona.amethyst.commons.chess.ChessRelayFetcher
+import com.vitorpamplona.amethyst.commons.chess.IUserMetadataProvider
+import com.vitorpamplona.amethyst.commons.chess.RelayGameSummary
+import com.vitorpamplona.amethyst.model.Account
+import com.vitorpamplona.amethyst.model.LocalCache
+import com.vitorpamplona.amethyst.model.filterIntoSet
+import com.vitorpamplona.quartz.nip64Chess.ChessGameEnd
+import com.vitorpamplona.quartz.nip64Chess.ChessGameEvents
+import com.vitorpamplona.quartz.nip64Chess.ChessMoveEvent
+import com.vitorpamplona.quartz.nip64Chess.Color
+import com.vitorpamplona.quartz.nip64Chess.LiveChessDrawOfferEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameAcceptEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameEndEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessMoveEvent
+
+/**
+ * Android implementation of ChessEventPublisher.
+ * Wraps account.signAndComputeBroadcast() for event publishing.
+ */
+class AndroidChessPublisher(
+    private val account: Account,
+) : ChessEventPublisher {
+    override suspend fun publishChallenge(
+        gameId: String,
+        playerColor: Color,
+        opponentPubkey: String?,
+        timeControl: String?,
+    ): Boolean =
+        try {
+            val template =
+                LiveChessGameChallengeEvent.build(
+                    gameId = gameId,
+                    playerColor = playerColor,
+                    opponentPubkey = opponentPubkey,
+                    timeControl = timeControl,
+                )
+            account.signAndComputeBroadcast(template)
+            true
+        } catch (e: Exception) {
+            false
+        }
+
+    override suspend fun publishAccept(
+        gameId: String,
+        challengeEventId: String,
+        challengerPubkey: String,
+    ): Boolean =
+        try {
+            val template =
+                LiveChessGameAcceptEvent.build(
+                    gameId = gameId,
+                    challengeEventId = challengeEventId,
+                    challengerPubkey = challengerPubkey,
+                )
+            account.signAndComputeBroadcast(template)
+            true
+        } catch (e: Exception) {
+            false
+        }
+
+    override suspend fun publishMove(move: ChessMoveEvent): Boolean =
+        try {
+            val template =
+                LiveChessMoveEvent.build(
+                    gameId = move.gameId,
+                    moveNumber = move.moveNumber,
+                    san = move.san,
+                    fen = move.fen,
+                    opponentPubkey = move.opponentPubkey,
+                )
+            account.signAndComputeBroadcast(template)
+            true
+        } catch (e: Exception) {
+            false
+        }
+
+    override suspend fun publishGameEnd(gameEnd: ChessGameEnd): Boolean =
+        try {
+            val template =
+                LiveChessGameEndEvent.build(
+                    gameId = gameEnd.gameId,
+                    result = gameEnd.result,
+                    termination = gameEnd.termination,
+                    winnerPubkey = gameEnd.winnerPubkey,
+                    opponentPubkey = gameEnd.opponentPubkey,
+                    pgn = gameEnd.pgn ?: "",
+                )
+            account.signAndComputeBroadcast(template)
+            true
+        } catch (e: Exception) {
+            false
+        }
+
+    override suspend fun publishDrawOffer(
+        gameId: String,
+        opponentPubkey: String,
+        message: String?,
+    ): Boolean =
+        try {
+            val template =
+                LiveChessDrawOfferEvent.build(
+                    gameId = gameId,
+                    opponentPubkey = opponentPubkey,
+                    message = message ?: "",
+                )
+            account.signAndComputeBroadcast(template)
+            true
+        } catch (e: Exception) {
+            false
+        }
+
+    override fun getWriteRelayCount(): Int = account.outboxRelays.flow.value.size
+}
+
+/**
+ * Android implementation of ChessRelayFetcher.
+ * Uses LocalCache for game state (hybrid approach during migration).
+ */
+class AndroidRelayFetcher(
+    private val account: Account,
+) : ChessRelayFetcher {
+    override suspend fun fetchGameEvents(gameId: String): ChessGameEvents {
+        // Query LocalCache for all game events
+        val challengeNotes =
+            LocalCache.addressables.filterIntoSet(LiveChessGameChallengeEvent.KIND) { _, note ->
+                val event = note.event as? LiveChessGameChallengeEvent ?: return@filterIntoSet false
+                event.gameId() == gameId
+            }
+        val challengeEvent = challengeNotes.firstOrNull()?.event as? LiveChessGameChallengeEvent
+
+        val acceptNotes =
+            LocalCache.addressables.filterIntoSet(LiveChessGameAcceptEvent.KIND) { _, note ->
+                val event = note.event as? LiveChessGameAcceptEvent ?: return@filterIntoSet false
+                event.gameId() == gameId
+            }
+        val acceptEvent = acceptNotes.firstOrNull()?.event as? LiveChessGameAcceptEvent
+
+        val moveNotes =
+            LocalCache.addressables.filterIntoSet(LiveChessMoveEvent.KIND) { _, note ->
+                val event = note.event as? LiveChessMoveEvent ?: return@filterIntoSet false
+                event.gameId() == gameId
+            }
+        val moveEvents = moveNotes.mapNotNull { it.event as? LiveChessMoveEvent }
+
+        val endNotes =
+            LocalCache.addressables.filterIntoSet(LiveChessGameEndEvent.KIND) { _, note ->
+                val event = note.event as? LiveChessGameEndEvent ?: return@filterIntoSet false
+                event.gameId() == gameId
+            }
+        val endEvent = endNotes.firstOrNull()?.event as? LiveChessGameEndEvent
+
+        return ChessGameEvents(
+            challenge = challengeEvent,
+            accept = acceptEvent,
+            moves = moveEvents,
+            end = endEvent,
+            drawOffers = emptyList(), // TODO: Fetch draw offers
+        )
+    }
+
+    override suspend fun fetchChallenges(): List<LiveChessGameChallengeEvent> {
+        val challengeNotes =
+            LocalCache.addressables.filterIntoSet(LiveChessGameChallengeEvent.KIND) { _, note ->
+                note.event is LiveChessGameChallengeEvent
+            }
+        return challengeNotes.mapNotNull { it.event as? LiveChessGameChallengeEvent }
+    }
+
+    override suspend fun fetchRecentGames(): List<RelayGameSummary> {
+        // Query LocalCache for recent active games
+        // Group moves by game ID and create summaries
+        val moveNotes =
+            LocalCache.addressables.filterIntoSet(LiveChessMoveEvent.KIND) { _, note ->
+                note.event is LiveChessMoveEvent
+            }
+        val gameIds = moveNotes.mapNotNull { (it.event as? LiveChessMoveEvent)?.gameId() }.distinct()
+
+        return gameIds.mapNotNull { gameId ->
+            val events = fetchGameEvents(gameId)
+            val challenge = events.challenge ?: return@mapNotNull null
+            val accept = events.accept
+
+            // Determine white/black pubkeys
+            val challengerColor = challenge.playerColor() ?: Color.WHITE
+            val whitePubkey =
+                if (challengerColor == Color.WHITE) {
+                    challenge.pubKey
+                } else {
+                    accept?.pubKey ?: return@mapNotNull null
+                }
+            val blackPubkey =
+                if (challengerColor == Color.BLACK) {
+                    challenge.pubKey
+                } else {
+                    accept?.pubKey ?: return@mapNotNull null
+                }
+
+            val lastMove = events.moves.maxByOrNull { it.createdAt }
+
+            RelayGameSummary(
+                gameId = gameId,
+                whitePubkey = whitePubkey,
+                blackPubkey = blackPubkey,
+                moveCount = events.moves.size,
+                lastMoveTime = lastMove?.createdAt ?: challenge.createdAt,
+                isActive = events.end == null,
+            )
+        }
+    }
+}
+
+/**
+ * Android implementation of IUserMetadataProvider.
+ * Wraps LocalCache.getOrCreateUser() for user metadata lookup.
+ */
+class AndroidMetadataProvider : IUserMetadataProvider {
+    override fun getDisplayName(pubkey: String): String {
+        val user = LocalCache.getOrCreateUser(pubkey)
+        return user.info?.bestName()
+            ?: user.pubkeyDisplayHex()
+    }
+
+    override fun getPictureUrl(pubkey: String): String? {
+        val user = LocalCache.getOrCreateUser(pubkey)
+        return user.info?.profilePicture()
+    }
+}

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

@@ -23,21 +23,32 @@ package com.vitorpamplona.amethyst.ui.screen.loggedIn.chess
 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.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 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.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.filled.CheckCircle
+import androidx.compose.material.icons.filled.Circle
+import androidx.compose.material.icons.filled.Settings
 import androidx.compose.material3.Button
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ModalBottomSheet
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
+import androidx.compose.material3.rememberModalBottomSheetState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
@@ -82,14 +93,29 @@ fun ChessGameScreen(
         )
 
     val activeGames by chessViewModel.activeGames.collectAsState()
+    val spectatingGames by chessViewModel.spectatingGames.collectAsState()
     val error by chessViewModel.error.collectAsState()
+    val chessStatus by chessViewModel.chessStatus.collectAsState()
     var isLoading by remember { mutableStateOf(true) }
     var loadedGameState by remember { mutableStateOf<LiveChessGameState?>(null) }
     var loadAttempted by remember { mutableStateOf(false) }
+    var showRelaySettings by remember { mutableStateOf(false) }
 
-    // Try to load game from cache if not in activeGames
-    LaunchedEffect(gameId, activeGames) {
-        val existingState = activeGames[gameId]
+    // Get relay information
+    val outboxRelays by accountViewModel.account.outboxRelays.flow
+        .collectAsState()
+    val writeRelays =
+        remember(outboxRelays) {
+            outboxRelays.map { it.toString() }
+        }
+
+    // Subscribe to chess events when game screen is visible
+    // This is critical - without it, no new events will arrive from relays
+    ChessSubscription(accountViewModel, chessViewModel)
+
+    // Try to load game from cache if not in activeGames or spectatingGames
+    LaunchedEffect(gameId, activeGames, spectatingGames) {
+        val existingState = activeGames[gameId] ?: spectatingGames[gameId]
         if (existingState != null) {
             loadedGameState = existingState
             isLoading = false
@@ -103,9 +129,9 @@ fun ChessGameScreen(
         }
     }
 
-    // Update state when activeGames changes (e.g., after refresh loads new moves)
-    LaunchedEffect(activeGames[gameId]) {
-        activeGames[gameId]?.let {
+    // Update state when games change (e.g., after refresh loads new moves)
+    LaunchedEffect(activeGames[gameId], spectatingGames[gameId]) {
+        (activeGames[gameId] ?: spectatingGames[gameId])?.let {
             loadedGameState = it
         }
     }
@@ -118,21 +144,47 @@ fun ChessGameScreen(
         }
     }
 
-    val gameState = loadedGameState ?: activeGames[gameId]
+    val gameState = loadedGameState ?: activeGames[gameId] ?: spectatingGames[gameId]
 
     Scaffold(
         topBar = {
-            TopAppBar(
-                title = { Text("Chess Game") },
-                navigationIcon = {
-                    IconButton(onClick = { nav.popBack() }) {
-                        Icon(
-                            imageVector = Icons.AutoMirrored.Filled.ArrowBack,
-                            contentDescription = "Back",
-                        )
-                    }
-                },
-            )
+            Column {
+                TopAppBar(
+                    title = { Text("Chess Game") },
+                    navigationIcon = {
+                        IconButton(onClick = { nav.popBack() }) {
+                            Icon(
+                                imageVector = Icons.AutoMirrored.Filled.ArrowBack,
+                                contentDescription = "Back",
+                            )
+                        }
+                    },
+                    actions = {
+                        IconButton(onClick = { showRelaySettings = true }) {
+                            Icon(
+                                imageVector = Icons.Default.Settings,
+                                contentDescription = "Relay Settings",
+                            )
+                        }
+                    },
+                )
+
+                // Status banner below top bar
+                ChessStatusBanner(
+                    status = chessStatus,
+                    onTap = {
+                        when (chessStatus) {
+                            is ChessStatus.MoveFailed -> {
+                                // Could implement retry logic here
+                            }
+                            is ChessStatus.Desynced -> {
+                                chessViewModel.forceRefresh()
+                            }
+                            else -> { }
+                        }
+                    },
+                )
+            }
         },
     ) { paddingValues ->
         when {
@@ -214,4 +266,112 @@ fun ChessGameScreen(
             }
         }
     }
+
+    // Relay settings bottom sheet
+    if (showRelaySettings) {
+        ModalBottomSheet(
+            onDismissRequest = { showRelaySettings = false },
+            sheetState = rememberModalBottomSheetState(),
+        ) {
+            RelaySettingsSheet(
+                writeRelays = writeRelays,
+                gameId = gameId,
+            )
+        }
+    }
+}
+
+/**
+ * Bottom sheet showing relay settings for the chess game
+ */
+@Composable
+private fun RelaySettingsSheet(
+    writeRelays: List<String>,
+    gameId: String,
+) {
+    Column(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .padding(16.dp),
+    ) {
+        Text(
+            text = "Chess Game Relays",
+            style = MaterialTheme.typography.titleLarge,
+            fontWeight = FontWeight.Bold,
+        )
+
+        Spacer(modifier = Modifier.height(8.dp))
+
+        Text(
+            text = "Moves are broadcast to these relays:",
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        if (writeRelays.isEmpty()) {
+            Text(
+                text = "No write relays configured",
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.error,
+            )
+        } else {
+            LazyColumn(
+                verticalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                items(writeRelays) { relay ->
+                    RelayItem(relayUrl = relay, isConnected = true)
+                }
+            }
+        }
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        HorizontalDivider()
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        Text(
+            text = "Game ID",
+            style = MaterialTheme.typography.titleSmall,
+            fontWeight = FontWeight.Bold,
+        )
+
+        Spacer(modifier = Modifier.height(4.dp))
+
+        Text(
+            text = gameId,
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+
+        Spacer(modifier = Modifier.height(32.dp))
+    }
+}
+
+@Composable
+private fun RelayItem(
+    relayUrl: String,
+    isConnected: Boolean,
+) {
+    Row(
+        modifier = Modifier.fillMaxWidth(),
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(12.dp),
+    ) {
+        Icon(
+            imageVector = if (isConnected) Icons.Default.CheckCircle else Icons.Default.Circle,
+            contentDescription = if (isConnected) "Connected" else "Disconnected",
+            tint = if (isConnected) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.error,
+            modifier = Modifier.size(16.dp),
+        )
+
+        Text(
+            text = relayUrl.removePrefix("wss://").removePrefix("ws://"),
+            style = MaterialTheme.typography.bodyMedium,
+            modifier = Modifier.weight(1f),
+        )
+    }
 }

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

@@ -31,24 +31,30 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 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.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.filled.Add
+import androidx.compose.material.icons.filled.CheckCircle
+import androidx.compose.material.icons.filled.Settings
 import androidx.compose.material3.Button
 import androidx.compose.material3.Card
 import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.FloatingActionButton
+import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ModalBottomSheet
 import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.pulltorefresh.PullToRefreshBox
+import androidx.compose.material3.rememberModalBottomSheetState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
@@ -71,6 +77,7 @@ import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.navigation.routes.Route
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.quartz.nip64Chess.ChessGameNameGenerator
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameState
 import kotlinx.coroutines.delay
@@ -92,15 +99,27 @@ fun ChessLobbyScreen(
         )
 
     val activeGames by chessViewModel.activeGames.collectAsState()
+    val spectatingGames by chessViewModel.spectatingGames.collectAsState()
+    val publicGames by chessViewModel.publicGames.collectAsState()
     val challenges by chessViewModel.challenges.collectAsState()
     val error by chessViewModel.error.collectAsState()
+    val chessStatus by chessViewModel.chessStatus.collectAsState()
     val selectedGameId by chessViewModel.selectedGameId.collectAsState()
     val userPubkey = accountViewModel.account.userProfile().pubkeyHex
 
     var showNewGameDialog by remember { mutableStateOf(false) }
+    var showRelaySettings by remember { mutableStateOf(false) }
     var isRefreshing by remember { mutableStateOf(false) }
     val scope = rememberCoroutineScope()
 
+    // Get relay information for settings display
+    val inboxRelays by accountViewModel.account.notificationRelays.flow
+        .collectAsState()
+    val outboxRelays by accountViewModel.account.outboxRelays.flow
+        .collectAsState()
+    val globalRelays by accountViewModel.account.defaultGlobalRelays.flow
+        .collectAsState()
+
     // Subscribe to chess events when screen is visible
     ChessSubscription(accountViewModel, chessViewModel)
 
@@ -139,6 +158,14 @@ fun ChessLobbyScreen(
                         )
                     }
                 },
+                actions = {
+                    IconButton(onClick = { showRelaySettings = true }) {
+                        Icon(
+                            imageVector = Icons.Default.Settings,
+                            contentDescription = "Relay Settings",
+                        )
+                    }
+                },
             )
         },
         floatingActionButton = {
@@ -170,6 +197,13 @@ fun ChessLobbyScreen(
                         .fillMaxSize()
                         .padding(horizontal = 16.dp),
             ) {
+                // Broadcast status banner
+                ChessStatusBanner(
+                    status = chessStatus,
+                    onTap = { /* no-op in lobby */ },
+                    modifier = Modifier.padding(bottom = 8.dp),
+                )
+
                 // Error display
                 error?.let { errorMsg ->
                     Card(
@@ -193,6 +227,8 @@ fun ChessLobbyScreen(
                 ChessLobbyContent(
                     challenges = challenges,
                     activeGames = activeGames,
+                    spectatingGames = spectatingGames,
+                    publicGames = publicGames,
                     userPubkey = userPubkey,
                     accountViewModel = accountViewModel,
                     onAcceptChallenge = { note ->
@@ -201,6 +237,10 @@ fun ChessLobbyScreen(
                     onSelectGame = { gameId ->
                         nav.nav(Route.ChessGame(gameId))
                     },
+                    onWatchGame = { gameId ->
+                        chessViewModel.loadGameAsSpectator(gameId)
+                        nav.nav(Route.ChessGame(gameId))
+                    },
                 )
             }
         }
@@ -216,18 +256,41 @@ fun ChessLobbyScreen(
             },
         )
     }
+
+    // Relay settings bottom sheet
+    if (showRelaySettings) {
+        ModalBottomSheet(
+            onDismissRequest = { showRelaySettings = false },
+            sheetState = rememberModalBottomSheetState(),
+        ) {
+            ChessRelaySettingsSheet(
+                inboxRelays = inboxRelays.map { it.toString() },
+                outboxRelays = outboxRelays.map { it.toString() },
+                globalRelays = globalRelays.map { it.toString() },
+                challengeCount = challenges.size,
+                publicGameCount = publicGames.size,
+            )
+        }
+    }
 }
 
 @Composable
 fun ChessLobbyContent(
     challenges: List<Note>,
     activeGames: Map<String, LiveChessGameState>,
+    spectatingGames: Map<String, LiveChessGameState>,
+    publicGames: List<PublicGameInfo>,
     userPubkey: String,
     accountViewModel: AccountViewModel,
     onAcceptChallenge: (Note) -> Unit,
     onSelectGame: (String) -> Unit,
+    onWatchGame: (String) -> Unit,
 ) {
-    if (activeGames.isEmpty() && challenges.isEmpty()) {
+    val hasContent =
+        activeGames.isNotEmpty() || spectatingGames.isNotEmpty() ||
+            publicGames.isNotEmpty() || challenges.isNotEmpty()
+
+    if (!hasContent) {
         // Empty state
         Box(
             modifier = Modifier.fillMaxSize(),
@@ -255,18 +318,18 @@ fun ChessLobbyContent(
     LazyColumn(
         verticalArrangement = Arrangement.spacedBy(8.dp),
     ) {
-        // Active games section
+        // Active games section (user is participant)
         if (activeGames.isNotEmpty()) {
             item {
                 Text(
-                    "Active Games",
+                    "Your Games",
                     style = MaterialTheme.typography.titleMedium,
                     fontWeight = FontWeight.Bold,
                     modifier = Modifier.padding(vertical = 8.dp),
                 )
             }
 
-            items(activeGames.entries.toList(), key = { it.key }) { (gameId, state) ->
+            items(activeGames.entries.toList(), key = { "active-${it.key}" }) { (gameId, state) ->
                 ActiveGameCard(
                     gameId = gameId,
                     opponentPubkey = state.opponentPubkey,
@@ -277,6 +340,28 @@ fun ChessLobbyContent(
             }
         }
 
+        // Games user is spectating
+        if (spectatingGames.isNotEmpty()) {
+            item {
+                Spacer(Modifier.height(16.dp))
+                Text(
+                    "Watching",
+                    style = MaterialTheme.typography.titleMedium,
+                    fontWeight = FontWeight.Bold,
+                    modifier = Modifier.padding(vertical = 8.dp),
+                )
+            }
+
+            items(spectatingGames.entries.toList(), key = { "spectating-${it.key}" }) { (gameId, state) ->
+                SpectatingGameCard(
+                    gameId = gameId,
+                    gameState = state,
+                    accountViewModel = accountViewModel,
+                    onClick = { onSelectGame(gameId) },
+                )
+            }
+        }
+
         // Incoming challenges
         val incomingChallenges =
             challenges.filter {
@@ -294,7 +379,7 @@ fun ChessLobbyContent(
                 )
             }
 
-            items(incomingChallenges, key = { it.idHex }) { note ->
+            items(incomingChallenges, key = { "incoming-${it.idHex}" }) { note ->
                 ChallengeCard(
                     note = note,
                     isIncoming = true,
@@ -304,31 +389,7 @@ fun ChessLobbyContent(
             }
         }
 
-        // User's outgoing challenges
-        val outgoingChallenges =
-            challenges.filter {
-                it.author?.pubkeyHex == userPubkey
-            }
-        if (outgoingChallenges.isNotEmpty()) {
-            item {
-                Spacer(Modifier.height(16.dp))
-                Text(
-                    "Your Challenges",
-                    style = MaterialTheme.typography.titleMedium,
-                    fontWeight = FontWeight.Bold,
-                    modifier = Modifier.padding(vertical = 8.dp),
-                )
-            }
-
-            items(outgoingChallenges, key = { it.idHex }) { note ->
-                OutgoingChallengeCard(
-                    note = note,
-                    accountViewModel = accountViewModel,
-                )
-            }
-        }
-
-        // Open challenges from others
+        // Open challenges from others (can join)
         val openChallenges =
             challenges.filter {
                 val event = it.event as? LiveChessGameChallengeEvent
@@ -345,7 +406,7 @@ fun ChessLobbyContent(
                 )
             }
 
-            items(openChallenges, key = { it.idHex }) { note ->
+            items(openChallenges, key = { "open-${it.idHex}" }) { note ->
                 ChallengeCard(
                     note = note,
                     isIncoming = false,
@@ -355,6 +416,51 @@ fun ChessLobbyContent(
             }
         }
 
+        // Live games to watch (public games user is not part of)
+        if (publicGames.isNotEmpty()) {
+            item {
+                Spacer(Modifier.height(16.dp))
+                Text(
+                    "Live Games",
+                    style = MaterialTheme.typography.titleMedium,
+                    fontWeight = FontWeight.Bold,
+                    modifier = Modifier.padding(vertical = 8.dp),
+                )
+            }
+
+            items(publicGames, key = { "public-${it.gameId}" }) { game ->
+                PublicGameCard(
+                    game = game,
+                    accountViewModel = accountViewModel,
+                    onWatch = { onWatchGame(game.gameId) },
+                )
+            }
+        }
+
+        // User's outgoing challenges (last, as they're just waiting)
+        val outgoingChallenges =
+            challenges.filter {
+                it.author?.pubkeyHex == userPubkey
+            }
+        if (outgoingChallenges.isNotEmpty()) {
+            item {
+                Spacer(Modifier.height(16.dp))
+                Text(
+                    "Your Challenges",
+                    style = MaterialTheme.typography.titleMedium,
+                    fontWeight = FontWeight.Bold,
+                    modifier = Modifier.padding(vertical = 8.dp),
+                )
+            }
+
+            items(outgoingChallenges, key = { "outgoing-${it.idHex}" }) { note ->
+                OutgoingChallengeCard(
+                    note = note,
+                    accountViewModel = accountViewModel,
+                )
+            }
+        }
+
         // Bottom padding for FAB
         item {
             Spacer(Modifier.height(80.dp))
@@ -375,6 +481,12 @@ private fun ActiveGameCard(
             accountViewModel.checkGetOrCreateUser(opponentPubkey)?.toBestDisplayName() ?: opponentPubkey.take(8)
         }
 
+    // Extract human-readable game name if available
+    val gameName =
+        remember(gameId) {
+            ChessGameNameGenerator.extractDisplayName(gameId) ?: gameId.take(12)
+        }
+
     Card(
         modifier = Modifier.fillMaxWidth().clickable(onClick = onClick),
         border =
@@ -391,14 +503,14 @@ private fun ActiveGameCard(
         ) {
             Column(modifier = Modifier.weight(1f)) {
                 Text(
-                    "vs $displayName",
-                    style = MaterialTheme.typography.bodyLarge,
-                    fontWeight = FontWeight.Medium,
+                    gameName,
+                    style = MaterialTheme.typography.titleSmall,
+                    fontWeight = FontWeight.Bold,
+                    color = MaterialTheme.colorScheme.primary,
                 )
                 Text(
-                    "Game: ${gameId.take(12)}...",
-                    style = MaterialTheme.typography.bodySmall,
-                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    "vs $displayName",
+                    style = MaterialTheme.typography.bodyMedium,
                 )
             }
 
@@ -515,3 +627,277 @@ private fun OutgoingChallengeCard(
         }
     }
 }
+
+@Composable
+private fun SpectatingGameCard(
+    gameId: String,
+    gameState: LiveChessGameState,
+    accountViewModel: AccountViewModel,
+    onClick: () -> Unit,
+) {
+    val moveCount =
+        gameState.moveHistory
+            .collectAsState()
+            .value.size
+
+    Card(
+        modifier = Modifier.fillMaxWidth().clickable(onClick = onClick),
+        border = BorderStroke(1.dp, Color(0xFF9C27B0)), // Purple for spectating
+    ) {
+        Row(
+            modifier = Modifier.padding(16.dp).fillMaxWidth(),
+            horizontalArrangement = Arrangement.spacedBy(12.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Column(modifier = Modifier.weight(1f)) {
+                Text(
+                    "Watching game",
+                    style = MaterialTheme.typography.bodyLarge,
+                    fontWeight = FontWeight.Medium,
+                )
+                Text(
+                    "$moveCount moves played",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+
+            Text(
+                "Spectating",
+                style = MaterialTheme.typography.bodyMedium,
+                color = Color(0xFF9C27B0),
+                fontWeight = FontWeight.Medium,
+            )
+        }
+    }
+}
+
+@Composable
+private fun PublicGameCard(
+    game: PublicGameInfo,
+    accountViewModel: AccountViewModel,
+    onWatch: () -> Unit,
+) {
+    val whiteName =
+        remember(game.whitePubkey) {
+            accountViewModel.checkGetOrCreateUser(game.whitePubkey)?.toBestDisplayName() ?: game.whitePubkey.take(8)
+        }
+    val blackName =
+        remember(game.blackPubkey) {
+            accountViewModel.checkGetOrCreateUser(game.blackPubkey)?.toBestDisplayName() ?: game.blackPubkey.take(8)
+        }
+
+    Card(
+        modifier = Modifier.fillMaxWidth(),
+        border = BorderStroke(1.dp, Color(0xFF2196F3)), // Blue for live games
+    ) {
+        Row(
+            modifier = Modifier.padding(16.dp).fillMaxWidth(),
+            horizontalArrangement = Arrangement.spacedBy(12.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Column(modifier = Modifier.weight(1f)) {
+                Text(
+                    "$whiteName vs $blackName",
+                    style = MaterialTheme.typography.bodyLarge,
+                    fontWeight = FontWeight.Medium,
+                )
+                Text(
+                    "${game.moveCount} moves",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+
+            OutlinedButton(onClick = onWatch) {
+                Text("Watch")
+            }
+        }
+    }
+}
+
+/**
+ * Bottom sheet showing relay settings and debug info for chess subscriptions
+ */
+@Composable
+private fun ChessRelaySettingsSheet(
+    inboxRelays: List<String>,
+    outboxRelays: List<String>,
+    globalRelays: List<String>,
+    challengeCount: Int,
+    publicGameCount: Int,
+) {
+    Column(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .padding(16.dp),
+    ) {
+        Text(
+            text = "Chess Relay Settings",
+            style = MaterialTheme.typography.titleLarge,
+            fontWeight = FontWeight.Bold,
+        )
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        // Stats section
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.SpaceEvenly,
+        ) {
+            Column(horizontalAlignment = Alignment.CenterHorizontally) {
+                Text(
+                    text = "$challengeCount",
+                    style = MaterialTheme.typography.headlineMedium,
+                    fontWeight = FontWeight.Bold,
+                    color = MaterialTheme.colorScheme.primary,
+                )
+                Text(
+                    text = "Challenges",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+            Column(horizontalAlignment = Alignment.CenterHorizontally) {
+                Text(
+                    text = "$publicGameCount",
+                    style = MaterialTheme.typography.headlineMedium,
+                    fontWeight = FontWeight.Bold,
+                    color = MaterialTheme.colorScheme.primary,
+                )
+                Text(
+                    text = "Live Games",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        }
+
+        Spacer(modifier = Modifier.height(16.dp))
+        HorizontalDivider()
+        Spacer(modifier = Modifier.height(16.dp))
+
+        // Inbox relays (where challenges TO you are fetched)
+        Text(
+            text = "Inbox Relays (${inboxRelays.size})",
+            style = MaterialTheme.typography.titleSmall,
+            fontWeight = FontWeight.Bold,
+        )
+        Text(
+            text = "Personal challenges are fetched from here",
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+        Spacer(modifier = Modifier.height(8.dp))
+        if (inboxRelays.isEmpty()) {
+            Text(
+                text = "No inbox relays configured",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.error,
+            )
+        } else {
+            inboxRelays.take(5).forEach { relay ->
+                RelayRow(relayUrl = relay)
+            }
+            if (inboxRelays.size > 5) {
+                Text(
+                    text = "+${inboxRelays.size - 5} more",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        }
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        // Global relays (where open challenges are fetched)
+        Text(
+            text = "Global Relays (${globalRelays.size})",
+            style = MaterialTheme.typography.titleSmall,
+            fontWeight = FontWeight.Bold,
+        )
+        Text(
+            text = "Open challenges and public games are fetched from here",
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+        Spacer(modifier = Modifier.height(8.dp))
+        if (globalRelays.isEmpty()) {
+            Text(
+                text = "No global relays configured - open challenges won't load!",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.error,
+            )
+        } else {
+            globalRelays.take(5).forEach { relay ->
+                RelayRow(relayUrl = relay)
+            }
+            if (globalRelays.size > 5) {
+                Text(
+                    text = "+${globalRelays.size - 5} more",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        }
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        // Outbox relays (where your challenges are published)
+        Text(
+            text = "Outbox Relays (${outboxRelays.size})",
+            style = MaterialTheme.typography.titleSmall,
+            fontWeight = FontWeight.Bold,
+        )
+        Text(
+            text = "Your challenges and moves are published here",
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+        Spacer(modifier = Modifier.height(8.dp))
+        if (outboxRelays.isEmpty()) {
+            Text(
+                text = "No outbox relays configured",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.error,
+            )
+        } else {
+            outboxRelays.take(5).forEach { relay ->
+                RelayRow(relayUrl = relay)
+            }
+            if (outboxRelays.size > 5) {
+                Text(
+                    text = "+${outboxRelays.size - 5} more",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        }
+
+        Spacer(modifier = Modifier.height(32.dp))
+    }
+}
+
+@Composable
+private fun RelayRow(relayUrl: String) {
+    Row(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .padding(vertical = 2.dp),
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(8.dp),
+    ) {
+        Icon(
+            imageVector = Icons.Default.CheckCircle,
+            contentDescription = "Connected",
+            tint = MaterialTheme.colorScheme.primary,
+            modifier = Modifier.size(12.dp),
+        )
+        Text(
+            text = relayUrl.removePrefix("wss://").removePrefix("ws://"),
+            style = MaterialTheme.typography.bodySmall,
+        )
+    }
+}

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

@@ -25,75 +25,61 @@ import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
-import com.vitorpamplona.amethyst.model.GLOBAL_FOLLOWS
-import com.vitorpamplona.amethyst.service.relayClient.composeSubscriptionManagers.ComposeSubscriptionManager
+import com.vitorpamplona.amethyst.commons.chess.subscription.ChessFilterBuilder
+import com.vitorpamplona.amethyst.commons.chess.subscription.ChessSubscriptionState
+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.amethyst.ui.screen.loggedIn.AccountViewModel
 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.nip01Core.relay.normalizer.NormalizedRelayUrl
-import com.vitorpamplona.quartz.nip64Chess.LiveChessGameAcceptEvent
-import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
-import com.vitorpamplona.quartz.nip64Chess.LiveChessGameEndEvent
-import com.vitorpamplona.quartz.nip64Chess.LiveChessMoveEvent
-import com.vitorpamplona.quartz.utils.TimeUtils
 
 /**
- * Default "since" window for challenges (24 hours)
- * Challenges older than this are considered expired anyway
- */
-private const val CHALLENGE_WINDOW_SECONDS = 24 * 60 * 60L
-
-/**
- * Default "since" window for game events when no EOSE cache exists (7 days)
- * This prevents loading ancient game history on first connection
- */
-private const val GAME_EVENT_WINDOW_SECONDS = 7 * 24 * 60 * 60L
-
-/**
- * Subscribe to chess events when the Chess tab is active.
- * Respects the Global/Follows filter from the discovery top bar.
+ * Subscribe to chess events when the Chess screen is active.
+ *
+ * Always uses global relays to ensure we see all chess events,
+ * regardless of the user's feed filter setting (Global/Follows).
  */
 @Composable
 fun ChessSubscription(
     accountViewModel: AccountViewModel,
     chessViewModel: ChessViewModel,
 ) {
-    // Observe the current filter selection (Global, All Follows, etc.)
-    val filterSelection by accountViewModel.account.settings.defaultDiscoveryFollowList
-        .collectAsStateWithLifecycle()
-
-    val isGlobal = filterSelection == GLOBAL_FOLLOWS
-
     // Get active game IDs from the view model for game-specific subscriptions
     val activeGames by chessViewModel.activeGames.collectAsStateWithLifecycle()
-    val activeGameIds = activeGames.keys
+    val spectatingGames by chessViewModel.spectatingGames.collectAsStateWithLifecycle()
+    val activeGameIds = activeGames.keys + spectatingGames.keys
+
+    // Extract opponent pubkeys for move filtering
+    val opponentPubkeys =
+        remember(activeGames) {
+            activeGames.values.map { it.opponentPubkey }.toSet()
+        }
 
     val state =
-        remember(accountViewModel.account, isGlobal, activeGameIds) {
+        remember(accountViewModel.account, activeGameIds, opponentPubkeys) {
             ChessQueryState(
                 userPubkey = accountViewModel.account.userProfile().pubkeyHex,
                 // Use notification inbox relays - where others send events TO us
                 inboxRelays = accountViewModel.account.notificationRelays.flow.value,
-                // Use proxy relays for global, outbox relays for follows
-                globalRelays =
-                    if (isGlobal) {
-                        accountViewModel.account.defaultGlobalRelays.flow.value
-                    } else {
-                        accountViewModel.account.followOutboxesOrProxy.flow.value
-                    },
-                isGlobal = isGlobal,
+                // Always use global relays for chess - we want to see ALL games
+                globalRelays = accountViewModel.account.defaultGlobalRelays.flow.value,
+                // Always treat as global for chess
+                isGlobal = true,
                 activeGameIds = activeGameIds,
+                opponentPubkeys = opponentPubkeys,
             )
         }
 
+    // Note: Chess subscription is now managed internally by ChessLobbyLogic.
+    // This composable is kept for backward compatibility but the actual
+    // subscription is handled by the ViewModel's ChessLobbyLogic instance.
+    // TODO: Step 7 will integrate this with the new ChessSubscriptionController
     DisposableEffect(state) {
-        accountViewModel.dataSources().chess.subscribe(state)
         chessViewModel.refreshChallenges()
         onDispose {
-            accountViewModel.dataSources().chess.unsubscribe(state)
+            // Subscription cleanup handled by ViewModel
         }
     }
 }
@@ -107,6 +93,7 @@ data class ChessQueryState(
     val globalRelays: Set<NormalizedRelayUrl>,
     val isGlobal: Boolean,
     val activeGameIds: Set<String> = emptySet(),
+    val opponentPubkeys: Set<String> = emptySet(),
 )
 
 /**
@@ -143,128 +130,33 @@ class ChessFeedFilterSubAssembler(
 }
 
 /**
- * Create relay filters for chess events.
+ * Create relay filters for chess events using the shared [ChessFilterBuilder].
  *
- * Creates filters based on the Global/Follows setting:
- * - Global: Fetch all chess events from global relays
- * - Follows: Fetch from followed users' outbox relays
+ * Following jesterui's approach:
+ * 1. Fetch ALL challenges from ALL connected relays (no author/tag restriction)
+ * 2. Filter client-side based on user's preferences (Global/Follows)
+ * 3. Game-specific subscriptions for active games
  *
- * Also always fetches challenges directed at the user from inbox relays.
- *
- * Improvements over basic implementation:
- * 1. Default "since" timestamps to avoid loading very old events on first connection
- * 2. Separate challenge filter (shorter window) from game events (longer window)
- * 3. Game-specific subscriptions for active games using #a tag references
- * 4. Grouped filters by relay to reduce subscription overhead
+ * This ensures we see:
+ * - Open challenges from anyone
+ * - Challenges directed at us
+ * - Public games to spectate
  */
 fun filterChessEvents(
     key: ChessQueryState,
     since: SincePerRelayMap?,
 ): List<RelayBasedFilter> {
-    val filters = mutableListOf<RelayBasedFilter>()
-    val now = TimeUtils.now()
-
-    // Challenge kinds only (for lobby display)
-    val challengeKinds =
-        listOf(
-            LiveChessGameChallengeEvent.KIND,
-            LiveChessGameAcceptEvent.KIND,
+    // Convert Android ChessQueryState to shared ChessSubscriptionState
+    val state =
+        ChessSubscriptionState(
+            userPubkey = key.userPubkey,
+            relays = key.inboxRelays + key.globalRelays,
+            activeGameIds = key.activeGameIds,
+            opponentPubkeys = key.opponentPubkeys,
         )
 
-    // Move/end kinds (for active games)
-    val gameEventKinds =
-        listOf(
-            LiveChessMoveEvent.KIND,
-            LiveChessGameEndEvent.KIND,
-        )
-
-    // All chess kinds
-    val allChessKinds = challengeKinds + gameEventKinds
-
-    // ========================================
-    // Filter 1: Personal challenges from inbox relays
-    // Uses 24h window for challenges (they expire anyway)
-    // ========================================
-    val inboxFilter =
-        Filter(
-            kinds = allChessKinds,
-            tags = mapOf("p" to listOf(key.userPubkey)),
-            limit = 100,
-        )
-
-    for (relay in key.inboxRelays) {
-        val sinceTime = since?.get(relay)?.time ?: (now - CHALLENGE_WINDOW_SECONDS)
-        filters.add(
-            RelayBasedFilter(
-                relay = relay,
-                filter = inboxFilter.copy(since = sinceTime),
-            ),
-        )
+    // Use shared filter builder for consistent behavior with Desktop
+    return ChessFilterBuilder.buildAllFilters(state) { relay ->
+        since?.get(relay)?.time
     }
-
-    // ========================================
-    // Filter 2: General challenges from global/outbox relays
-    // Uses 24h window to show recent open challenges
-    // ========================================
-    val globalChallengeFilter =
-        Filter(
-            kinds = challengeKinds,
-            limit = 50,
-        )
-
-    for (relay in key.globalRelays) {
-        val sinceTime = since?.get(relay)?.time ?: (now - CHALLENGE_WINDOW_SECONDS)
-        filters.add(
-            RelayBasedFilter(
-                relay = relay,
-                filter = globalChallengeFilter.copy(since = sinceTime),
-            ),
-        )
-    }
-
-    // ========================================
-    // Filter 3: Active game events
-    // Uses longer window (7 days) or no window for active games
-    // Follows jesterui pattern: subscribe to game-specific events via #d tag
-    // ========================================
-    if (key.activeGameIds.isNotEmpty()) {
-        // Create filters for each active game's events
-        // Using #d tag to match the game_id in addressable events
-        val gameSpecificFilter =
-            Filter(
-                kinds = gameEventKinds,
-                tags = mapOf("d" to key.activeGameIds.toList()),
-                limit = 200, // More moves per game
-            )
-
-        // Query all relays for active game events (no since - need full history)
-        val allRelays = key.inboxRelays + key.globalRelays
-        for (relay in allRelays) {
-            filters.add(
-                RelayBasedFilter(
-                    relay = relay,
-                    filter = gameSpecificFilter,
-                ),
-            )
-        }
-    } else {
-        // No active games - use general game event filter with window
-        val generalGameFilter =
-            Filter(
-                kinds = gameEventKinds,
-                limit = 100,
-            )
-
-        for (relay in key.globalRelays) {
-            val sinceTime = since?.get(relay)?.time ?: (now - GAME_EVENT_WINDOW_SECONDS)
-            filters.add(
-                RelayBasedFilter(
-                    relay = relay,
-                    filter = generalGameFilter.copy(since = sinceTime),
-                ),
-            )
-        }
-    }
-
-    return filters
 }

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

@@ -29,14 +29,17 @@ import com.vitorpamplona.amethyst.model.LocalCache
 import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.model.filterIntoSet
 import com.vitorpamplona.quartz.nip64Chess.ChessEngine
+import com.vitorpamplona.quartz.nip64Chess.ChessGameNameGenerator
 import com.vitorpamplona.quartz.nip64Chess.ChessMoveEvent
 import com.vitorpamplona.quartz.nip64Chess.Color
+import com.vitorpamplona.quartz.nip64Chess.GameResult
 import com.vitorpamplona.quartz.nip64Chess.LiveChessDrawOfferEvent
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameAcceptEvent
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameEndEvent
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameState
 import com.vitorpamplona.quartz.nip64Chess.LiveChessMoveEvent
+import com.vitorpamplona.quartz.nip64Chess.PieceType
 import com.vitorpamplona.quartz.utils.TimeUtils
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
@@ -44,7 +47,6 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.launch
-import java.util.UUID
 
 /**
  * ViewModel for managing chess game state, challenges, and event publishing
@@ -64,11 +66,19 @@ class ChessViewModel(
         const val CLEANUP_INTERVAL_MS = 5 * 60 * 1000L
     }
 
-    // Active games being played
+    // Active games being played (user is a participant)
     private val _activeGames = MutableStateFlow<Map<String, LiveChessGameState>>(emptyMap())
     val activeGames: StateFlow<Map<String, LiveChessGameState>> = _activeGames.asStateFlow()
 
-    // Pending challenges (incoming and outgoing)
+    // Public games we can spectate (user is NOT a participant)
+    private val _publicGames = MutableStateFlow<List<PublicGameInfo>>(emptyList())
+    val publicGames: StateFlow<List<PublicGameInfo>> = _publicGames.asStateFlow()
+
+    // Spectating games (user is watching but not playing)
+    private val _spectatingGames = MutableStateFlow<Map<String, LiveChessGameState>>(emptyMap())
+    val spectatingGames: StateFlow<Map<String, LiveChessGameState>> = _spectatingGames.asStateFlow()
+
+    // Pending challenges (ALL non-expired challenges)
     private val _challenges = MutableStateFlow<List<Note>>(emptyList())
     val challenges: StateFlow<List<Note>> = _challenges.asStateFlow()
 
@@ -88,6 +98,14 @@ class ChessViewModel(
     private val _pendingRetries = MutableStateFlow<Map<String, RetryOperation>>(emptyMap())
     val pendingRetries: StateFlow<Map<String, RetryOperation>> = _pendingRetries.asStateFlow()
 
+    // Chess status for UI feedback (broadcasting, syncing, etc.)
+    private val _chessStatus = MutableStateFlow<ChessStatus>(ChessStatus.Idle)
+    val chessStatus: StateFlow<ChessStatus> = _chessStatus.asStateFlow()
+
+    // Connected relays for display
+    private val _connectedRelays = MutableStateFlow<List<String>>(emptyList())
+    val connectedRelays: StateFlow<List<String>> = _connectedRelays.asStateFlow()
+
     // Polling delegate for periodic refresh
     private val pollingDelegate =
         ChessPollingDelegate(
@@ -101,6 +119,9 @@ class ChessViewModel(
             },
         )
 
+    // Track games currently being created to prevent race conditions (like Desktop)
+    private val gamesBeingCreated = mutableSetOf<String>()
+
     init {
         subscribeToChessEvents()
         // Start polling - will do initial fetch
@@ -201,6 +222,11 @@ class ChessViewModel(
      * Handle game acceptance event
      */
     private fun handleGameAccepted(event: LiveChessGameAcceptEvent) {
+        val gameId = event.gameId() ?: return
+
+        // Skip if game already exists (prevents overwrite)
+        if (_activeGames.value.containsKey(gameId)) return
+
         // Check if this is acceptance of our challenge
         if (event.challengerPubkey() == account.signer.pubKey) {
             startGameFromAcceptance(event)
@@ -267,6 +293,14 @@ class ChessViewModel(
         val gameId = generateGameId()
 
         viewModelScope.launch(Dispatchers.IO) {
+            val relayCount = acc.outboxRelays.flow.value.size
+            _chessStatus.value =
+                ChessStatus.BroadcastingMove(
+                    san = "Challenge",
+                    successCount = 0,
+                    totalRelays = relayCount,
+                )
+
             val success =
                 retryWithBackoff("challenge-$gameId") {
                     val template =
@@ -281,8 +315,23 @@ class ChessViewModel(
                 }
 
             if (success) {
+                _chessStatus.value =
+                    ChessStatus.MoveSuccess(
+                        san = "Challenge",
+                        relayCount = relayCount,
+                    )
                 _error.value = null
+                refreshChallenges()
+                delay(3000)
+                if (_chessStatus.value is ChessStatus.MoveSuccess) {
+                    _chessStatus.value = ChessStatus.Idle
+                }
             } else {
+                _chessStatus.value =
+                    ChessStatus.MoveFailed(
+                        san = "Challenge",
+                        error = "Failed after $MAX_RETRIES attempts",
+                    )
                 _error.value = "Failed to create challenge after $MAX_RETRIES attempts"
             }
         }
@@ -297,6 +346,11 @@ class ChessViewModel(
         challengerPubkey: String,
         playerColor: Color,
     ) {
+        // Mark as being created to prevent duplicate from relay echo
+        synchronized(gamesBeingCreated) {
+            if (!gamesBeingCreated.add(gameId)) return // Already being created
+        }
+
         viewModelScope.launch(Dispatchers.IO) {
             try {
                 val template =
@@ -308,6 +362,16 @@ class ChessViewModel(
 
                 account.signAndComputeBroadcast(template)
 
+                // Check if game was already created by relay echo while we were broadcasting
+                if (_activeGames.value.containsKey(gameId)) {
+                    synchronized(gamesBeingCreated) {
+                        gamesBeingCreated.remove(gameId)
+                    }
+                    _selectedGameId.value = gameId
+                    _error.value = null
+                    return@launch
+                }
+
                 // Create game state
                 val engine = ChessEngine()
                 engine.reset()
@@ -322,10 +386,16 @@ class ChessViewModel(
                     )
 
                 _activeGames.value = _activeGames.value + (gameId to gameState)
+                synchronized(gamesBeingCreated) {
+                    gamesBeingCreated.remove(gameId)
+                }
                 pollingDelegate.addGameId(gameId)
                 _selectedGameId.value = gameId
                 _error.value = null
             } catch (e: Exception) {
+                synchronized(gamesBeingCreated) {
+                    gamesBeingCreated.remove(gameId)
+                }
                 _error.value = "Failed to accept challenge: ${e.message}"
             }
         }
@@ -338,6 +408,13 @@ class ChessViewModel(
         val challengeEvent = challengeNote.event as? LiveChessGameChallengeEvent ?: return
 
         val gameId = challengeEvent.gameId() ?: return
+
+        // Skip if game already exists (prevents overwrite)
+        if (_activeGames.value.containsKey(gameId)) {
+            _selectedGameId.value = gameId
+            return
+        }
+
         val challengerPubkey = challengeEvent.pubKey
         val challengerColor = challengeEvent.playerColor() ?: Color.WHITE
         val playerColor = challengerColor.opposite()
@@ -353,6 +430,13 @@ class ChessViewModel(
 
         viewModelScope.launch(Dispatchers.IO) {
             val gameId = acceptEvent.gameId() ?: return@launch
+
+            // Skip if game already exists or is being created (prevents overwrite)
+            if (_activeGames.value.containsKey(gameId)) return@launch
+            synchronized(gamesBeingCreated) {
+                if (!gamesBeingCreated.add(gameId)) return@launch // Already being created
+            }
+
             val opponentPubkey = acceptEvent.pubKey
 
             // Find our challenge to get player color
@@ -376,6 +460,9 @@ class ChessViewModel(
                 )
 
             _activeGames.value = _activeGames.value + (gameId to gameState)
+            synchronized(gamesBeingCreated) {
+                gamesBeingCreated.remove(gameId)
+            }
             pollingDelegate.addGameId(gameId)
             _selectedGameId.value = gameId
         }
@@ -390,12 +477,36 @@ class ChessViewModel(
         to: String,
     ) {
         val gameState = _activeGames.value[gameId] ?: return
-        val moveResult = gameState.makeMove(from, to)
+
+        // Parse promotion from 'to' if present (e.g., "e8q" -> square="e8", promotion=QUEEN)
+        val (targetSquare, promotion) = parsePromotionFromTarget(to)
+
+        val moveResult = gameState.makeMove(from, targetSquare, promotion)
         if (moveResult != null) {
             publishMove(gameId, moveResult)
         }
     }
 
+    /**
+     * Parse promotion piece from target square string.
+     * e.g., "e8q" -> ("e8", QUEEN), "e4" -> ("e4", null)
+     */
+    private fun parsePromotionFromTarget(to: String): Pair<String, PieceType?> {
+        if (to.length == 3) {
+            val square = to.substring(0, 2)
+            val promotion =
+                when (to[2].lowercaseChar()) {
+                    'q' -> PieceType.QUEEN
+                    'r' -> PieceType.ROOK
+                    'b' -> PieceType.BISHOP
+                    'n' -> PieceType.KNIGHT
+                    else -> null
+                }
+            return square to promotion
+        }
+        return to to null
+    }
+
     /**
      * Publish a move for the current game (full version with ChessMoveEvent)
      */
@@ -405,6 +516,15 @@ class ChessViewModel(
     ) {
         viewModelScope.launch(Dispatchers.IO) {
             try {
+                // Update status to broadcasting
+                val relayCount = account.outboxRelays.flow.value.size
+                _chessStatus.value =
+                    ChessStatus.BroadcastingMove(
+                        san = moveEvent.san,
+                        successCount = 0,
+                        totalRelays = relayCount,
+                    )
+
                 val template =
                     LiveChessMoveEvent.build(
                         gameId = moveEvent.gameId,
@@ -415,8 +535,33 @@ class ChessViewModel(
                     )
 
                 account.signAndComputeBroadcast(template)
+
+                // Update status to success
+                _chessStatus.value =
+                    ChessStatus.MoveSuccess(
+                        san = moveEvent.san,
+                        relayCount = relayCount,
+                    )
+
+                // Clear status after delay
+                delay(3000)
+                if (_chessStatus.value is ChessStatus.MoveSuccess) {
+                    val gameState = _activeGames.value[gameId]
+                    _chessStatus.value =
+                        if (gameState?.isPlayerTurn() == false) {
+                            ChessStatus.WaitingForOpponent
+                        } else {
+                            ChessStatus.Idle
+                        }
+                }
+
                 _error.value = null
             } catch (e: Exception) {
+                _chessStatus.value =
+                    ChessStatus.MoveFailed(
+                        san = moveEvent.san,
+                        error = e.message ?: "Unknown error",
+                    )
                 _error.value = "Failed to publish move: ${e.message}"
             }
         }
@@ -508,28 +653,241 @@ class ChessViewModel(
 
     /**
      * Refresh challenges from local cache
+     *
+     * Following jesterui pattern: fetch ALL non-expired challenges,
+     * let UI filter by category (incoming, outgoing, open)
+     *
+     * NOTE: Chess events are addressable (kinds 30064+), so we query LocalCache.addressables
      */
     fun refreshChallenges() {
         viewModelScope.launch(Dispatchers.IO) {
             val userPubkey = account.signer.pubKey
             val now = TimeUtils.now()
 
-            // Query LocalCache for chess challenge events
+            // Query LocalCache.addressables for chess challenge events (kind 30064)
+            // Chess events are addressable events, not regular notes!
             val challengeNotes =
-                LocalCache.notes.filterIntoSet { _, note ->
+                LocalCache.addressables.filterIntoSet(LiveChessGameChallengeEvent.KIND) { _, note ->
                     val event = note.event as? LiveChessGameChallengeEvent ?: return@filterIntoSet false
 
-                    // Check if challenge is not expired
+                    // Check if challenge is not expired (24h)
                     val createdAt = event.createdAt
                     if ((now - createdAt) >= CHALLENGE_EXPIRY_SECONDS) return@filterIntoSet false
 
-                    // Include challenges directed at us, or open challenges (not from us)
+                    // Check if game isn't already active (accepted)
+                    val gameId = event.gameId() ?: return@filterIntoSet false
+                    if (_activeGames.value.containsKey(gameId)) return@filterIntoSet false
+
+                    // Include all challenges:
+                    // - Directed at us
+                    // - Open challenges (no specific opponent)
+                    // - Our own challenges (waiting for accept)
                     val opponentPubkey = event.opponentPubkey()
-                    opponentPubkey == userPubkey || (opponentPubkey == null && event.pubKey != userPubkey) || event.pubKey == userPubkey
+                    val isDirectedAtUs = opponentPubkey == userPubkey
+                    val isOpenChallenge = opponentPubkey == null
+                    val isFromUs = event.pubKey == userPubkey
+
+                    isDirectedAtUs || isOpenChallenge || isFromUs
                 }
 
             _challenges.value = challengeNotes.toList()
             updateBadgeCount()
+
+            // Also refresh public games
+            refreshPublicGames()
+        }
+    }
+
+    /**
+     * Refresh list of public games that can be spectated
+     *
+     * NOTE: Chess events are addressable (kinds 30064+), so we query LocalCache.addressables
+     */
+    private fun refreshPublicGames() {
+        val userPubkey = account.signer.pubKey
+        val now = TimeUtils.now()
+
+        // Find all games where both challenge and accept exist
+        // Game ID -> (ChallengeEvent, AcceptEvent)
+        val gameData = mutableMapOf<String, Pair<LiveChessGameChallengeEvent?, LiveChessGameAcceptEvent?>>()
+
+        // Collect challenges from addressables (kind 30064)
+        LocalCache.addressables.filterIntoSet(LiveChessGameChallengeEvent.KIND) { _, note ->
+            val event = note.event as? LiveChessGameChallengeEvent ?: return@filterIntoSet false
+            val gameId = event.gameId() ?: return@filterIntoSet false
+            gameData[gameId] = (event to gameData[gameId]?.second)
+            false // Don't need to collect, just iterate
+        }
+
+        // Collect accepts from addressables (kind 30065)
+        LocalCache.addressables.filterIntoSet(LiveChessGameAcceptEvent.KIND) { _, note ->
+            val event = note.event as? LiveChessGameAcceptEvent ?: return@filterIntoSet false
+            val gameId = event.gameId() ?: return@filterIntoSet false
+            gameData[gameId] = (gameData[gameId]?.first to event)
+            false
+        }
+
+        // Filter to games that are active and user is NOT a participant
+        val publicGames = mutableListOf<PublicGameInfo>()
+
+        for ((gameId, data) in gameData) {
+            val (challenge, accept) = data
+            if (challenge == null || accept == null) continue
+
+            // Skip if user is a participant
+            val challengerPubkey = challenge.pubKey
+            val acceptorPubkey = accept.pubKey
+            if (challengerPubkey == userPubkey || acceptorPubkey == userPubkey) continue
+
+            // Skip if already in our active/spectating games
+            if (_activeGames.value.containsKey(gameId) || _spectatingGames.value.containsKey(gameId)) continue
+
+            // Determine white/black based on challenger color
+            val challengerColor = challenge.playerColor() ?: Color.WHITE
+            val (whitePubkey, blackPubkey) =
+                if (challengerColor == Color.WHITE) {
+                    challengerPubkey to acceptorPubkey
+                } else {
+                    acceptorPubkey to challengerPubkey
+                }
+
+            // Count moves and get last move time from addressables (kind 30066)
+            var moveCount = 0
+            var lastMoveTime = accept.createdAt
+
+            LocalCache.addressables.filterIntoSet(LiveChessMoveEvent.KIND) { _, note ->
+                val moveEvent = note.event as? LiveChessMoveEvent ?: return@filterIntoSet false
+                if (moveEvent.gameId() != gameId) return@filterIntoSet false
+                moveCount++
+                if (moveEvent.createdAt > lastMoveTime) {
+                    lastMoveTime = moveEvent.createdAt
+                }
+                false
+            }
+
+            // Skip inactive games (no moves in 24 hours)
+            if ((now - lastMoveTime) > CHALLENGE_EXPIRY_SECONDS) continue
+
+            publicGames.add(
+                PublicGameInfo(
+                    gameId = gameId,
+                    whitePubkey = whitePubkey,
+                    blackPubkey = blackPubkey,
+                    moveCount = moveCount,
+                    lastMoveTime = lastMoveTime,
+                ),
+            )
+        }
+
+        // Sort by most recent activity
+        _publicGames.value = publicGames.sortedByDescending { it.lastMoveTime }
+    }
+
+    /**
+     * Load a game as spectator (watch-only mode)
+     * Returns the game state or null if loading failed
+     *
+     * NOTE: Chess events are addressable (kinds 30064+), so we query LocalCache.addressables
+     */
+    fun loadGameAsSpectator(gameId: String): LiveChessGameState? {
+        // Check if already spectating
+        _spectatingGames.value[gameId]?.let { return it }
+
+        // Check if we're actually a participant (shouldn't load as spectator)
+        _activeGames.value[gameId]?.let {
+            _error.value = "You are a participant in this game"
+            return null
+        }
+
+        val userPubkey = account.signer.pubKey
+
+        // Find challenge and accept events from addressables
+        val challengeNotes =
+            LocalCache.addressables.filterIntoSet(LiveChessGameChallengeEvent.KIND) { _, note ->
+                val event = note.event as? LiveChessGameChallengeEvent ?: return@filterIntoSet false
+                event.gameId() == gameId
+            }
+        val acceptNotes =
+            LocalCache.addressables.filterIntoSet(LiveChessGameAcceptEvent.KIND) { _, note ->
+                val event = note.event as? LiveChessGameAcceptEvent ?: return@filterIntoSet false
+                event.gameId() == gameId
+            }
+
+        val challengeEvent = challengeNotes.firstOrNull()?.event as? LiveChessGameChallengeEvent
+        val acceptEvent = acceptNotes.firstOrNull()?.event as? LiveChessGameAcceptEvent
+
+        if (challengeEvent == null) {
+            _error.value = "Challenge not found for game"
+            return null
+        }
+
+        if (acceptEvent == null) {
+            _error.value = "Game not started yet - waiting for opponent"
+            return null
+        }
+
+        // Determine white/black
+        val challengerPubkey = challengeEvent.pubKey
+        val acceptorPubkey = acceptEvent.pubKey
+        val challengerColor = challengeEvent.playerColor() ?: Color.WHITE
+
+        val (whitePubkey, blackPubkey) =
+            if (challengerColor == Color.WHITE) {
+                challengerPubkey to acceptorPubkey
+            } else {
+                acceptorPubkey to challengerPubkey
+            }
+
+        // Build engine state by replaying moves from addressables
+        val engine = ChessEngine()
+        engine.reset()
+
+        val moveNotes =
+            LocalCache.addressables.filterIntoSet(LiveChessMoveEvent.KIND) { _, note ->
+                val event = note.event as? LiveChessMoveEvent ?: return@filterIntoSet false
+                event.gameId() == gameId
+            }
+
+        val sortedMoves =
+            moveNotes
+                .mapNotNull { it.event as? LiveChessMoveEvent }
+                .sortedBy { it.moveNumber() ?: Int.MAX_VALUE }
+
+        for (moveEvent in sortedMoves) {
+            val san = moveEvent.san() ?: continue
+            try {
+                engine.makeMove(san)
+            } catch (e: Exception) {
+                _error.value = "Error loading move $san: ${e.message}"
+            }
+        }
+
+        // Create spectator game state - always view from white's perspective
+        val gameState =
+            LiveChessGameState(
+                gameId = gameId,
+                playerPubkey = userPubkey,
+                opponentPubkey = blackPubkey, // Opponent relative to spectator view (white)
+                playerColor = Color.WHITE, // Spectators see from white's perspective
+                engine = engine,
+                isSpectator = true,
+            )
+
+        // Add to spectating games
+        _spectatingGames.value = _spectatingGames.value + (gameId to gameState)
+        pollingDelegate.addGameId(gameId)
+
+        _error.value = null
+        return gameState
+    }
+
+    /**
+     * Stop spectating a game
+     */
+    fun stopSpectating(gameId: String) {
+        if (_spectatingGames.value.containsKey(gameId)) {
+            _spectatingGames.value = _spectatingGames.value - gameId
+            pollingDelegate.removeGameId(gameId)
         }
     }
 
@@ -629,32 +987,31 @@ class ChessViewModel(
     }
 
     /**
-     * Generate unique game ID
+     * Generate unique game ID with human-readable component
      */
-    private fun generateGameId(): String {
-        val timestamp = TimeUtils.now()
-        val random = UUID.randomUUID().toString().take(8)
-        return "chess-$timestamp-$random"
-    }
+    private fun generateGameId(): String = ChessGameNameGenerator.generateGameId(TimeUtils.now())
 
     /**
      * Refresh game state from LocalCache for specific game IDs
      * Called periodically by polling delegate
+     *
+     * NOTE: Chess events are addressable (kinds 30064+), so we query LocalCache.addressables
      */
     private suspend fun refreshGamesFromCache(gameIds: Set<String>) {
         val userPubkey = account.signer.pubKey
 
         for (gameId in gameIds) {
-            // Find moves for this game
+            // Find moves for this game from addressables (kind 30066)
             val moveNotes =
-                LocalCache.notes.filterIntoSet { _, note ->
+                LocalCache.addressables.filterIntoSet(LiveChessMoveEvent.KIND) { _, note ->
                     val event = note.event as? LiveChessMoveEvent ?: return@filterIntoSet false
                     event.gameId() == gameId
                 }
 
-            val gameState = _activeGames.value[gameId]
-            if (gameState != null) {
-                // Apply any new moves
+            // Check active games first
+            val activeGameState = _activeGames.value[gameId]
+            if (activeGameState != null) {
+                // Apply any new moves from opponent
                 moveNotes
                     .mapNotNull { it.event as? LiveChessMoveEvent }
                     .filter { it.pubKey != userPubkey } // Only opponent moves
@@ -663,9 +1020,29 @@ class ChessViewModel(
                         val san = moveEvent.san() ?: return@forEach
                         val fen = moveEvent.fen() ?: return@forEach
                         val moveNumber = moveEvent.moveNumber()
-                        gameState.applyOpponentMove(san, fen, moveNumber)
+                        activeGameState.applyOpponentMove(san, fen, moveNumber)
                     }
             }
+
+            // Check spectating games - apply ALL moves (from both players)
+            val spectatingGameState = _spectatingGames.value[gameId]
+            if (spectatingGameState != null) {
+                moveNotes
+                    .mapNotNull { it.event as? LiveChessMoveEvent }
+                    .sortedBy { it.moveNumber() }
+                    .forEach { moveEvent ->
+                        val san = moveEvent.san() ?: return@forEach
+                        val fen = moveEvent.fen() ?: return@forEach
+                        val moveNumber = moveEvent.moveNumber()
+                        spectatingGameState.applyOpponentMove(san, fen, moveNumber)
+                    }
+            }
+
+            // Game is being polled but not yet active — accept event may have arrived since
+            // initial load. Retry loading from cache to pick up late-arriving accept events.
+            if (activeGameState == null && spectatingGameState == null) {
+                loadGameFromCache(gameId)
+            }
         }
 
         updateBadgeCount()
@@ -675,6 +1052,8 @@ class ChessViewModel(
      * Load or rebuild game state from LocalCache for a specific gameId
      * Used when navigating to a game screen
      *
+     * NOTE: Chess events are addressable (kinds 30064+), so we query LocalCache.addressables
+     *
      * @return GameLoadResult with either the game state or an error reason
      */
     fun loadGameFromCache(gameId: String): LiveChessGameState? {
@@ -683,17 +1062,17 @@ class ChessViewModel(
 
         val userPubkey = account.signer.pubKey
 
-        // Find the challenge event for this game
+        // Find the challenge event for this game from addressables (kind 30064)
         val challengeNotes =
-            LocalCache.notes.filterIntoSet { _, note ->
+            LocalCache.addressables.filterIntoSet(LiveChessGameChallengeEvent.KIND) { _, note ->
                 val event = note.event as? LiveChessGameChallengeEvent ?: return@filterIntoSet false
                 event.gameId() == gameId
             }
         val challengeNote = challengeNotes.firstOrNull()
 
-        // Find accept event for this game
+        // Find accept event for this game from addressables (kind 30065)
         val acceptNotes =
-            LocalCache.notes.filterIntoSet { _, note ->
+            LocalCache.addressables.filterIntoSet(LiveChessGameAcceptEvent.KIND) { _, note ->
                 val event = note.event as? LiveChessGameAcceptEvent ?: return@filterIntoSet false
                 event.gameId() == gameId
             }
@@ -724,9 +1103,10 @@ class ChessViewModel(
                     challengerColor.opposite() to challengerPubkey
                 }
                 challengerPubkey == userPubkey && acceptorPubkey == null -> {
-                    // We created challenge but no one accepted yet
-                    _error.value = "Waiting for opponent to accept challenge"
-                    return null
+                    // We created challenge but no one accepted yet - show it anyway
+                    // Use targeted opponent or empty string for open challenges
+                    val targetedOpponent = challengeEvent.opponentPubkey() ?: ""
+                    challengerColor to targetedOpponent
                 }
                 else -> {
                     _error.value = "You are not a participant in this game"
@@ -738,9 +1118,9 @@ class ChessViewModel(
         val engine = ChessEngine()
         engine.reset()
 
-        // Find and apply all moves in order
+        // Find and apply all moves in order from addressables (kind 30066)
         val moveNotes =
-            LocalCache.notes.filterIntoSet { _, note ->
+            LocalCache.addressables.filterIntoSet(LiveChessMoveEvent.KIND) { _, note ->
                 val event = note.event as? LiveChessMoveEvent ?: return@filterIntoSet false
                 event.gameId() == gameId
             }
@@ -767,6 +1147,10 @@ class ChessViewModel(
             }
         }
 
+        // Only pending if we're the challenger, no accept event found, AND no moves exist
+        // (moves prove the game was accepted even if accept event isn't in cache)
+        val isPendingChallenge = challengerPubkey == userPubkey && acceptorPubkey == null && sortedMoves.isEmpty()
+
         val gameState =
             LiveChessGameState(
                 gameId = gameId,
@@ -774,13 +1158,28 @@ class ChessViewModel(
                 opponentPubkey = opponentPubkey,
                 playerColor = playerColor,
                 engine = engine,
+                isPendingChallenge = isPendingChallenge,
             )
 
         // Mark loaded moves as received to prevent re-application during refresh
         gameState.markMovesAsReceived(loadedMoveNumbers)
 
-        // Add to active games
-        _activeGames.value = _activeGames.value + (gameId to gameState)
+        // Check for end event (kind 30067) — game may have been resigned/finished
+        val endNotes =
+            LocalCache.addressables.filterIntoSet(LiveChessGameEndEvent.KIND) { _, note ->
+                val event = note.event as? LiveChessGameEndEvent ?: return@filterIntoSet false
+                event.gameId() == gameId
+            }
+        val endEvent = endNotes.firstOrNull()?.event as? LiveChessGameEndEvent
+        if (endEvent != null) {
+            val result = GameResult.parse(endEvent.result() ?: "*")
+            gameState.markAsFinished(result)
+        }
+
+        // Only add to active games if not pending (pending challenges are view-only)
+        if (!isPendingChallenge) {
+            _activeGames.value = _activeGames.value + (gameId to gameState)
+        }
 
         // Update polling delegate with this game
         pollingDelegate.addGameId(gameId)
@@ -808,3 +1207,14 @@ data class RetryOperation(
     val currentAttempt: Int,
     val maxAttempts: Int,
 )
+
+/**
+ * Info about a public game that can be spectated
+ */
+data class PublicGameInfo(
+    val gameId: String,
+    val whitePubkey: String,
+    val blackPubkey: String,
+    val moveCount: Int,
+    val lastMoveTime: Long,
+)

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/chess/ChessLobbyLogic.kt

@@ -0,0 +1,632 @@
+/**
+ * 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.chess
+
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip64Chess.ChessGameEnd
+import com.vitorpamplona.quartz.nip64Chess.ChessGameEvents
+import com.vitorpamplona.quartz.nip64Chess.ChessMoveEvent
+import com.vitorpamplona.quartz.nip64Chess.Color
+import com.vitorpamplona.quartz.nip64Chess.LiveChessDrawOfferEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameAcceptEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameEndEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessMoveEvent
+import com.vitorpamplona.quartz.utils.TimeUtils
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import java.util.UUID
+
+/**
+ * Interface for platform-specific chess event publishing
+ */
+interface ChessEventPublisher {
+    suspend fun publishChallenge(
+        gameId: String,
+        playerColor: Color,
+        opponentPubkey: String?,
+        timeControl: String?,
+    ): Boolean
+
+    suspend fun publishAccept(
+        gameId: String,
+        challengeEventId: String,
+        challengerPubkey: String,
+    ): Boolean
+
+    suspend fun publishMove(move: ChessMoveEvent): Boolean
+
+    suspend fun publishGameEnd(gameEnd: ChessGameEnd): Boolean
+
+    suspend fun publishDrawOffer(
+        gameId: String,
+        opponentPubkey: String,
+        message: String?,
+    ): Boolean
+
+    fun getWriteRelayCount(): Int
+}
+
+/**
+ * Relay-first fetcher interface. Platforms provide one-shot relay queries.
+ *
+ * Every fetch does: one-shot REQ → collect events → EOSE → close.
+ * No caching — relays are the single source of truth.
+ */
+interface ChessRelayFetcher {
+    /** Fetch all events for a specific game */
+    suspend fun fetchGameEvents(gameId: String): ChessGameEvents
+
+    /** Fetch recent challenge events */
+    suspend fun fetchChallenges(): List<LiveChessGameChallengeEvent>
+
+    /** Fetch recent public game summaries for spectating */
+    suspend fun fetchRecentGames(): List<RelayGameSummary>
+}
+
+/**
+ * Summary of a game found on relays (for lobby display / spectating)
+ */
+data class RelayGameSummary(
+    val gameId: String,
+    val whitePubkey: String,
+    val blackPubkey: String,
+    val moveCount: Int,
+    val lastMoveTime: Long,
+    val isActive: Boolean,
+)
+
+/**
+ * Shared chess lobby logic — relay-first architecture.
+ *
+ * Both Android and Desktop use this identically.
+ * Platform-specific code only implements:
+ * - ChessEventPublisher: sign + broadcast events
+ * - ChessRelayFetcher: one-shot relay queries
+ * - IUserMetadataProvider: display names / avatars
+ */
+class ChessLobbyLogic(
+    private val userPubkey: String,
+    private val publisher: ChessEventPublisher,
+    private val fetcher: ChessRelayFetcher,
+    private val metadataProvider: IUserMetadataProvider,
+    private val scope: CoroutineScope,
+    pollingConfig: ChessPollingConfig = ChessPollingDefaults.android,
+) {
+    val state = ChessLobbyState(userPubkey, scope)
+
+    private val pollingDelegate =
+        ChessPollingDelegate(
+            config = pollingConfig,
+            scope = scope,
+            onRefreshGames = { gameIds -> refreshGames(gameIds) },
+            onRefreshChallenges = { refreshChallenges() },
+            onCleanup = { cleanupExpiredChallenges() },
+        )
+
+    // ========================================
+    // Lifecycle
+    // ========================================
+
+    fun startPolling() = pollingDelegate.start()
+
+    fun stopPolling() = pollingDelegate.stop()
+
+    fun forceRefresh() = pollingDelegate.refreshNow()
+
+    // ========================================
+    // Incoming event routing (real-time / optimistic)
+    // ========================================
+
+    /**
+     * Route an incoming relay event to the appropriate handler.
+     * Called by platform subscription callbacks for real-time updates.
+     */
+    fun handleIncomingEvent(event: Event) {
+        when (event) {
+            is LiveChessGameChallengeEvent -> handleChallenge(event)
+            is LiveChessGameAcceptEvent -> handleAccept(event)
+            is LiveChessMoveEvent -> handleMove(event)
+            is LiveChessGameEndEvent -> handleGameEnd(event)
+            is LiveChessDrawOfferEvent -> handleDrawOffer(event)
+        }
+    }
+
+    private fun handleChallenge(event: LiveChessGameChallengeEvent) {
+        val gameId = event.gameId() ?: return
+        val challengerColor = event.playerColor() ?: Color.WHITE
+
+        val challenge =
+            ChessChallenge(
+                eventId = event.id,
+                gameId = gameId,
+                challengerPubkey = event.pubKey,
+                challengerDisplayName = metadataProvider.getDisplayName(event.pubKey),
+                challengerAvatarUrl = metadataProvider.getPictureUrl(event.pubKey),
+                opponentPubkey = event.opponentPubkey(),
+                challengerColor = challengerColor,
+                createdAt = event.createdAt,
+            )
+        state.addChallenge(challenge)
+    }
+
+    private fun handleAccept(event: LiveChessGameAcceptEvent) {
+        val gameId = event.gameId() ?: return
+
+        // If this is an accept for our challenge, auto-load the game
+        val ourChallenge = state.outgoingChallenges().find { it.gameId == gameId }
+        if (ourChallenge != null) {
+            handleGameAccepted(gameId)
+        }
+    }
+
+    private fun handleMove(event: LiveChessMoveEvent) {
+        val gameId = event.gameId() ?: return
+        val san = event.san() ?: return
+        val fen = event.fen() ?: return
+        val moveNumber = event.moveNumber()
+
+        val gameState = state.getGameState(gameId) ?: return
+
+        // Only apply opponent moves optimistically
+        if (event.pubKey != userPubkey) {
+            gameState.applyOpponentMove(san, fen, moveNumber)
+        }
+    }
+
+    private fun handleGameEnd(event: LiveChessGameEndEvent) {
+        val gameId = event.gameId() ?: return
+        val gameState = state.getGameState(gameId) ?: return
+
+        val resultStr = event.result()
+        val result =
+            when (resultStr) {
+                "1-0" -> com.vitorpamplona.quartz.nip64Chess.GameResult.WHITE_WINS
+                "0-1" -> com.vitorpamplona.quartz.nip64Chess.GameResult.BLACK_WINS
+                "1/2-1/2" -> com.vitorpamplona.quartz.nip64Chess.GameResult.DRAW
+                else -> return
+            }
+
+        gameState.markAsFinished(result)
+        state.moveToCompleted(gameId, result.notation, event.termination())
+        pollingDelegate.removeGameId(gameId)
+    }
+
+    private fun handleDrawOffer(event: LiveChessDrawOfferEvent) {
+        val gameId = event.gameId() ?: return
+        val gameState = state.getGameState(gameId) ?: return
+
+        if (event.pubKey != userPubkey) {
+            gameState.receiveDrawOffer(event.pubKey)
+        }
+    }
+
+    // ========================================
+    // Challenge operations
+    // ========================================
+
+    fun createChallenge(
+        opponentPubkey: String? = null,
+        playerColor: Color = Color.WHITE,
+        timeControl: String? = null,
+    ) {
+        val gameId = generateGameId()
+
+        scope.launch(Dispatchers.Default) {
+            state.setBroadcastStatus(
+                ChessBroadcastStatus.Broadcasting(
+                    san = "Challenge",
+                    successCount = 0,
+                    totalRelays = publisher.getWriteRelayCount(),
+                ),
+            )
+
+            val success = retryWithBackoff { publisher.publishChallenge(gameId, playerColor, opponentPubkey, timeControl) }
+
+            if (success) {
+                state.setBroadcastStatus(
+                    ChessBroadcastStatus.Success("Challenge", publisher.getWriteRelayCount()),
+                )
+                delay(2000)
+                state.setBroadcastStatus(ChessBroadcastStatus.Idle)
+                state.setError(null)
+            } else {
+                state.setBroadcastStatus(
+                    ChessBroadcastStatus.Failed("Challenge", "Failed to publish"),
+                )
+                state.setError("Failed to create challenge")
+            }
+        }
+    }
+
+    fun acceptChallenge(challenge: ChessChallenge) {
+        scope.launch(Dispatchers.Default) {
+            val success =
+                retryWithBackoff {
+                    publisher.publishAccept(
+                        gameId = challenge.gameId,
+                        challengeEventId = challenge.eventId,
+                        challengerPubkey = challenge.challengerPubkey,
+                    )
+                }
+
+            if (success) {
+                val playerColor = challenge.challengerColor.opposite()
+                val gameState =
+                    ChessGameLoader.createNewGame(
+                        gameId = challenge.gameId,
+                        playerPubkey = userPubkey,
+                        opponentPubkey = challenge.challengerPubkey,
+                        playerColor = playerColor,
+                    )
+                state.addActiveGame(challenge.gameId, gameState)
+                pollingDelegate.addGameId(challenge.gameId)
+                state.selectGame(challenge.gameId)
+                state.setError(null)
+            } else {
+                state.setError("Failed to accept challenge")
+            }
+        }
+    }
+
+    /**
+     * When we detect our challenge was accepted, load game from relays.
+     */
+    fun handleGameAccepted(gameId: String) {
+        scope.launch(Dispatchers.Default) {
+            state.setBroadcastStatus(ChessBroadcastStatus.Syncing(0f))
+
+            val events = fetcher.fetchGameEvents(gameId)
+            val result = ChessGameLoader.loadGame(events, userPubkey)
+
+            when (result) {
+                is LoadGameResult.Success -> {
+                    state.addActiveGame(gameId, result.liveState)
+                    pollingDelegate.addGameId(gameId)
+                    state.selectGame(gameId)
+                    state.setBroadcastStatus(ChessBroadcastStatus.Idle)
+                    state.setError(null)
+                }
+                is LoadGameResult.Error -> {
+                    state.setError("Failed to load game: ${result.message}")
+                    state.setBroadcastStatus(ChessBroadcastStatus.Idle)
+                }
+            }
+        }
+    }
+
+    // ========================================
+    // Game operations
+    // ========================================
+
+    fun publishMove(
+        gameId: String,
+        from: String,
+        to: String,
+    ) {
+        val gameState = state.getGameState(gameId) ?: return
+
+        if (state.isSpectating(gameId)) {
+            state.setError("Cannot move while spectating")
+            return
+        }
+
+        val moveResult = gameState.makeMove(from, to) ?: return
+
+        scope.launch(Dispatchers.Default) {
+            state.setBroadcastStatus(
+                ChessBroadcastStatus.Broadcasting(
+                    san = moveResult.san,
+                    successCount = 0,
+                    totalRelays = publisher.getWriteRelayCount(),
+                ),
+            )
+
+            val success = retryWithBackoff { publisher.publishMove(moveResult) }
+
+            if (success) {
+                state.setBroadcastStatus(
+                    ChessBroadcastStatus.Success(moveResult.san, publisher.getWriteRelayCount()),
+                )
+                delay(3000)
+
+                val currentState = state.getGameState(gameId)
+                state.setBroadcastStatus(
+                    if (currentState?.isPlayerTurn() == false) {
+                        ChessBroadcastStatus.WaitingForOpponent
+                    } else {
+                        ChessBroadcastStatus.Idle
+                    },
+                )
+                state.setError(null)
+            } else {
+                state.setBroadcastStatus(
+                    ChessBroadcastStatus.Failed(moveResult.san, "Failed to publish move"),
+                )
+                state.setError("Failed to publish move")
+            }
+        }
+    }
+
+    fun resign(gameId: String) {
+        val gameState = state.getGameState(gameId) ?: return
+
+        if (state.isSpectating(gameId)) {
+            state.setError("Cannot resign while spectating")
+            return
+        }
+
+        scope.launch(Dispatchers.Default) {
+            val endData = gameState.resign()
+            val success = retryWithBackoff { publisher.publishGameEnd(endData) }
+
+            if (success) {
+                state.moveToCompleted(gameId, endData.result.notation, endData.termination.name.lowercase())
+                pollingDelegate.removeGameId(gameId)
+                state.setError(null)
+            } else {
+                state.setError("Failed to resign")
+            }
+        }
+    }
+
+    fun offerDraw(gameId: String) {
+        val gameState = state.getGameState(gameId) ?: return
+
+        if (state.isSpectating(gameId)) {
+            state.setError("Cannot offer draw while spectating")
+            return
+        }
+
+        scope.launch(Dispatchers.Default) {
+            val drawOffer = gameState.offerDraw()
+            val success =
+                retryWithBackoff {
+                    publisher.publishDrawOffer(
+                        gameId = drawOffer.gameId,
+                        opponentPubkey = drawOffer.opponentPubkey,
+                        message = drawOffer.message,
+                    )
+                }
+
+            if (success) {
+                state.setError(null)
+            } else {
+                state.setError("Failed to offer draw")
+            }
+        }
+    }
+
+    fun acceptDraw(gameId: String) {
+        val gameState = state.getGameState(gameId) ?: return
+        val endData = gameState.acceptDraw() ?: return
+
+        scope.launch(Dispatchers.Default) {
+            val success = retryWithBackoff { publisher.publishGameEnd(endData) }
+
+            if (success) {
+                state.moveToCompleted(gameId, endData.result.notation, "draw_agreement")
+                pollingDelegate.removeGameId(gameId)
+                state.setError(null)
+            } else {
+                state.setError("Failed to accept draw")
+            }
+        }
+    }
+
+    fun declineDraw(gameId: String) {
+        val gameState = state.getGameState(gameId) ?: return
+        gameState.declineDraw()
+    }
+
+    fun claimAbandonmentVictory(gameId: String) {
+        val gameState = state.getGameState(gameId) ?: return
+        val endData = gameState.claimAbandonmentVictory() ?: return
+
+        scope.launch(Dispatchers.Default) {
+            val success = retryWithBackoff { publisher.publishGameEnd(endData) }
+
+            if (success) {
+                state.moveToCompleted(gameId, endData.result.notation, "abandonment")
+                pollingDelegate.removeGameId(gameId)
+                state.setError(null)
+            } else {
+                state.setError("Failed to claim abandonment victory")
+            }
+        }
+    }
+
+    // ========================================
+    // Spectator mode
+    // ========================================
+
+    fun loadGameAsSpectator(gameId: String) {
+        scope.launch(Dispatchers.Default) {
+            state.setBroadcastStatus(ChessBroadcastStatus.Syncing(0f))
+
+            val events = fetcher.fetchGameEvents(gameId)
+            val result = ChessGameLoader.loadGame(events, userPubkey)
+
+            when (result) {
+                is LoadGameResult.Success -> {
+                    state.addSpectatingGame(gameId, result.liveState)
+                    pollingDelegate.addGameId(gameId)
+                    state.selectGame(gameId)
+                    state.setBroadcastStatus(ChessBroadcastStatus.Idle)
+                    state.setError(null)
+                }
+                is LoadGameResult.Error -> {
+                    state.setError("Failed to load game: ${result.message}")
+                    state.setBroadcastStatus(ChessBroadcastStatus.Idle)
+                }
+            }
+        }
+    }
+
+    fun loadGame(gameId: String) {
+        scope.launch(Dispatchers.Default) {
+            if (state.getGameState(gameId) != null) {
+                state.selectGame(gameId)
+                return@launch
+            }
+
+            state.setBroadcastStatus(ChessBroadcastStatus.Syncing(0f))
+
+            val events = fetcher.fetchGameEvents(gameId)
+            val result = ChessGameLoader.loadGame(events, userPubkey)
+
+            when (result) {
+                is LoadGameResult.Success -> {
+                    if (result.liveState.isSpectator) {
+                        state.addSpectatingGame(gameId, result.liveState)
+                    } else {
+                        state.addActiveGame(gameId, result.liveState)
+                    }
+                    pollingDelegate.addGameId(gameId)
+                    state.selectGame(gameId)
+                    state.setBroadcastStatus(ChessBroadcastStatus.Idle)
+                    state.setError(null)
+                }
+                is LoadGameResult.Error -> {
+                    state.setError("Failed to load game: ${result.message}")
+                    state.setBroadcastStatus(ChessBroadcastStatus.Idle)
+                }
+            }
+        }
+    }
+
+    // ========================================
+    // Relay-first refresh (periodic reconstruction)
+    // ========================================
+
+    /**
+     * Full reconstruction refresh for active games.
+     * One-shot REQ → transient collector → reconstruct → diff + update.
+     */
+    private suspend fun refreshGames(gameIds: Set<String>) {
+        for (gameId in gameIds) {
+            refreshGame(gameId)
+        }
+    }
+
+    private suspend fun refreshGame(gameId: String) {
+        val events = fetcher.fetchGameEvents(gameId)
+        val result = ChessGameLoader.loadGame(events, userPubkey)
+
+        when (result) {
+            is LoadGameResult.Success -> {
+                state.replaceGameState(gameId, result.liveState)
+            }
+            is LoadGameResult.Error -> {
+                // Don't overwrite error for periodic refresh failures
+            }
+        }
+    }
+
+    private suspend fun refreshChallenges() {
+        val challengeEvents = fetcher.fetchChallenges()
+
+        val challenges =
+            challengeEvents.mapNotNull { event ->
+                val gameId = event.gameId() ?: return@mapNotNull null
+                val challengerColor = event.playerColor() ?: Color.WHITE
+
+                ChessChallenge(
+                    eventId = event.id,
+                    gameId = gameId,
+                    challengerPubkey = event.pubKey,
+                    challengerDisplayName = metadataProvider.getDisplayName(event.pubKey),
+                    challengerAvatarUrl = metadataProvider.getPictureUrl(event.pubKey),
+                    opponentPubkey = event.opponentPubkey(),
+                    challengerColor = challengerColor,
+                    createdAt = event.createdAt,
+                )
+            }
+
+        state.updateChallenges(challenges)
+
+        // Also refresh public games
+        val recentGames = fetcher.fetchRecentGames()
+        val publicGames =
+            recentGames.map { summary ->
+                PublicGame(
+                    gameId = summary.gameId,
+                    whitePubkey = summary.whitePubkey,
+                    whiteDisplayName = metadataProvider.getDisplayName(summary.whitePubkey),
+                    blackPubkey = summary.blackPubkey,
+                    blackDisplayName = metadataProvider.getDisplayName(summary.blackPubkey),
+                    moveCount = summary.moveCount,
+                    lastMoveTime = summary.lastMoveTime,
+                    isActive = summary.isActive,
+                )
+            }
+        state.updatePublicGames(publicGames)
+    }
+
+    private fun cleanupExpiredChallenges() {
+        val now = TimeUtils.now()
+        val validChallenges =
+            state.challenges.value.filter { challenge ->
+                (now - challenge.createdAt) < CHALLENGE_EXPIRY_SECONDS
+            }
+        state.updateChallenges(validChallenges)
+    }
+
+    // ========================================
+    // Utilities
+    // ========================================
+
+    private fun generateGameId(): String {
+        val timestamp = TimeUtils.now()
+        val random = UUID.randomUUID().toString().take(8)
+        return "chess-$timestamp-$random"
+    }
+
+    /**
+     * Retry a publish operation with exponential backoff.
+     * Returns true if any attempt succeeds.
+     */
+    private suspend fun retryWithBackoff(
+        maxRetries: Int = 3,
+        initialDelayMs: Long = 1000,
+        action: suspend () -> Boolean,
+    ): Boolean {
+        var delayMs = initialDelayMs
+        repeat(maxRetries) { attempt ->
+            if (action()) return true
+            if (attempt < maxRetries - 1) {
+                delay(delayMs)
+                delayMs *= 2
+            }
+        }
+        return false
+    }
+
+    fun clearError() {
+        state.setError(null)
+    }
+
+    fun selectGame(gameId: String?) {
+        state.selectGame(gameId)
+    }
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/chess/ChessLobbyState.kt

@@ -0,0 +1,367 @@
+/**
+ * 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.chess
+
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.quartz.nip64Chess.Color
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameState
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+
+/**
+ * Challenge expiry: 24 hours
+ */
+const val CHALLENGE_EXPIRY_SECONDS = 24 * 60 * 60L
+
+/**
+ * Represents a chess challenge that can be displayed in the lobby
+ */
+@Immutable
+data class ChessChallenge(
+    val eventId: String,
+    val gameId: String,
+    val challengerPubkey: String,
+    val challengerDisplayName: String?,
+    val challengerAvatarUrl: String?,
+    val opponentPubkey: String?,
+    val challengerColor: Color,
+    val createdAt: Long,
+) {
+    /** Whether this is an open challenge anyone can accept */
+    val isOpen: Boolean get() = opponentPubkey == null
+
+    /** Whether this challenge is directed at a specific user */
+    fun isDirectedAt(pubkey: String): Boolean = opponentPubkey == pubkey
+
+    /** Whether this challenge was created by a specific user */
+    fun isFrom(pubkey: String): Boolean = challengerPubkey == pubkey
+}
+
+/**
+ * Represents a public game that can be spectated
+ */
+@Immutable
+data class PublicGame(
+    val gameId: String,
+    val whitePubkey: String,
+    val whiteDisplayName: String?,
+    val blackPubkey: String,
+    val blackDisplayName: String?,
+    val moveCount: Int,
+    val lastMoveTime: Long,
+    val isActive: Boolean,
+)
+
+/**
+ * Represents a completed game for history display
+ */
+@Immutable
+data class CompletedGame(
+    val gameId: String,
+    val whitePubkey: String,
+    val whiteDisplayName: String?,
+    val blackPubkey: String,
+    val blackDisplayName: String?,
+    val result: String,
+    val termination: String?,
+    val moveCount: Int,
+    val completedAt: Long,
+) {
+    /** Whether user won this game */
+    fun didUserWin(userPubkey: String): Boolean =
+        when (result) {
+            "1-0" -> whitePubkey == userPubkey
+            "0-1" -> blackPubkey == userPubkey
+            else -> false
+        }
+
+    /** Whether this was a draw */
+    val isDraw: Boolean get() = result == "1/2-1/2"
+}
+
+/**
+ * Chess status for UI feedback
+ */
+@Immutable
+sealed class ChessBroadcastStatus {
+    data object Idle : ChessBroadcastStatus()
+
+    data class Broadcasting(
+        val san: String,
+        val successCount: Int,
+        val totalRelays: Int,
+    ) : ChessBroadcastStatus() {
+        val progress: Float get() = if (totalRelays > 0) successCount.toFloat() / totalRelays else 0f
+    }
+
+    data class Success(
+        val san: String,
+        val relayCount: Int,
+    ) : ChessBroadcastStatus()
+
+    data class Failed(
+        val san: String,
+        val error: String,
+    ) : ChessBroadcastStatus()
+
+    data object WaitingForOpponent : ChessBroadcastStatus()
+
+    data class Syncing(
+        val progress: Float = 0f,
+    ) : ChessBroadcastStatus()
+
+    data class Desynced(
+        val message: String,
+    ) : ChessBroadcastStatus()
+}
+
+/**
+ * Shared chess lobby state that can be used by both Android and Desktop
+ */
+class ChessLobbyState(
+    private val userPubkey: String,
+    private val scope: CoroutineScope,
+) {
+    // Active games where user is a participant
+    private val _activeGames = MutableStateFlow<Map<String, LiveChessGameState>>(emptyMap())
+    val activeGames: StateFlow<Map<String, LiveChessGameState>> = _activeGames.asStateFlow()
+
+    // Public games that can be spectated
+    private val _publicGames = MutableStateFlow<List<PublicGame>>(emptyList())
+    val publicGames: StateFlow<List<PublicGame>> = _publicGames.asStateFlow()
+
+    // All challenges (filtered by UI based on type)
+    private val _challenges = MutableStateFlow<List<ChessChallenge>>(emptyList())
+    val challenges: StateFlow<List<ChessChallenge>> = _challenges.asStateFlow()
+
+    // Spectating games (user is watching but not playing)
+    private val _spectatingGames = MutableStateFlow<Map<String, LiveChessGameState>>(emptyMap())
+    val spectatingGames: StateFlow<Map<String, LiveChessGameState>> = _spectatingGames.asStateFlow()
+
+    // Completed games history
+    private val _completedGames = MutableStateFlow<List<CompletedGame>>(emptyList())
+    val completedGames: StateFlow<List<CompletedGame>> = _completedGames.asStateFlow()
+
+    // Broadcast status
+    private val _broadcastStatus = MutableStateFlow<ChessBroadcastStatus>(ChessBroadcastStatus.Idle)
+    val broadcastStatus: StateFlow<ChessBroadcastStatus> = _broadcastStatus.asStateFlow()
+
+    // Error state
+    private val _error = MutableStateFlow<String?>(null)
+    val error: StateFlow<String?> = _error.asStateFlow()
+
+    // Selected game ID for navigation
+    private val _selectedGameId = MutableStateFlow<String?>(null)
+    val selectedGameId: StateFlow<String?> = _selectedGameId.asStateFlow()
+
+    // Badge count (incoming challenges + your turn games)
+    val badgeCount: Int
+        get() {
+            val incomingChallenges = _challenges.value.count { it.isDirectedAt(userPubkey) }
+            val yourTurnGames = _activeGames.value.values.count { it.isPlayerTurn() }
+            return incomingChallenges + yourTurnGames
+        }
+
+    // ========================================
+    // Derived state for UI sections
+    // ========================================
+
+    /** Challenges directed at the user */
+    fun incomingChallenges(): List<ChessChallenge> = _challenges.value.filter { it.isDirectedAt(userPubkey) }
+
+    /** Challenges created by the user */
+    fun outgoingChallenges(): List<ChessChallenge> = _challenges.value.filter { it.isFrom(userPubkey) }
+
+    /** Open challenges from others that user can join */
+    fun openChallenges(): List<ChessChallenge> = _challenges.value.filter { it.isOpen && !it.isFrom(userPubkey) }
+
+    // ========================================
+    // State updates
+    // ========================================
+
+    fun updateChallenges(challenges: List<ChessChallenge>) {
+        _challenges.value = challenges
+    }
+
+    fun addChallenge(challenge: ChessChallenge) {
+        _challenges.update { current ->
+            if (current.any { it.eventId == challenge.eventId || it.gameId == challenge.gameId }) {
+                current
+            } else {
+                current + challenge
+            }
+        }
+    }
+
+    fun removeChallenge(gameId: String) {
+        _challenges.update { current ->
+            current.filter { it.gameId != gameId }
+        }
+    }
+
+    fun updatePublicGames(games: List<PublicGame>) {
+        _publicGames.value = games
+    }
+
+    fun addActiveGame(
+        gameId: String,
+        state: LiveChessGameState,
+    ) {
+        _activeGames.update { it + (gameId to state) }
+        // Remove from challenges if present
+        removeChallenge(gameId)
+    }
+
+    fun removeActiveGame(gameId: String) {
+        _activeGames.update { it - gameId }
+    }
+
+    fun updateActiveGame(
+        gameId: String,
+        update: (LiveChessGameState) -> LiveChessGameState,
+    ) {
+        _activeGames.update { current ->
+            current[gameId]?.let { state ->
+                current + (gameId to update(state))
+            } ?: current
+        }
+    }
+
+    /**
+     * Replace game state entirely after full reconstruction from relays.
+     * Preserves game location (active vs spectating).
+     */
+    fun replaceGameState(
+        gameId: String,
+        newState: LiveChessGameState,
+    ) {
+        if (_activeGames.value.containsKey(gameId)) {
+            _activeGames.update { it + (gameId to newState) }
+        } else if (_spectatingGames.value.containsKey(gameId)) {
+            _spectatingGames.update { it + (gameId to newState) }
+        }
+    }
+
+    /**
+     * Move a game from active/spectating to completed.
+     * Display names are optional; UI can look them up later if needed.
+     */
+    fun moveToCompleted(
+        gameId: String,
+        result: String,
+        termination: String?,
+        whiteDisplayName: String? = null,
+        blackDisplayName: String? = null,
+    ) {
+        val existingState = _activeGames.value[gameId] ?: _spectatingGames.value[gameId]
+        existingState?.let { gameState ->
+            // Derive white/black pubkeys from player color
+            val whitePubkey =
+                if (gameState.playerColor == Color.WHITE) {
+                    gameState.playerPubkey
+                } else {
+                    gameState.opponentPubkey
+                }
+            val blackPubkey =
+                if (gameState.playerColor == Color.BLACK) {
+                    gameState.playerPubkey
+                } else {
+                    gameState.opponentPubkey
+                }
+
+            val completed =
+                CompletedGame(
+                    gameId = gameId,
+                    whitePubkey = whitePubkey,
+                    whiteDisplayName = whiteDisplayName,
+                    blackPubkey = blackPubkey,
+                    blackDisplayName = blackDisplayName,
+                    result = result,
+                    termination = termination,
+                    moveCount = gameState.moveHistory.value.size,
+                    completedAt =
+                        com.vitorpamplona.quartz.utils.TimeUtils
+                            .now(),
+                )
+
+            _completedGames.update { current ->
+                // Avoid duplicates
+                if (current.any { it.gameId == gameId }) {
+                    current
+                } else {
+                    listOf(completed) + current
+                }
+            }
+
+            // Remove from active/spectating
+            _activeGames.update { it - gameId }
+            _spectatingGames.update { it - gameId }
+
+            // Clear selection if this game was selected
+            if (_selectedGameId.value == gameId) {
+                _selectedGameId.value = null
+            }
+        }
+    }
+
+    fun addSpectatingGame(
+        gameId: String,
+        state: LiveChessGameState,
+    ) {
+        _spectatingGames.update { it + (gameId to state) }
+    }
+
+    fun removeSpectatingGame(gameId: String) {
+        _spectatingGames.update { it - gameId }
+    }
+
+    fun setBroadcastStatus(status: ChessBroadcastStatus) {
+        _broadcastStatus.value = status
+    }
+
+    fun setError(error: String?) {
+        _error.value = error
+    }
+
+    fun selectGame(gameId: String?) {
+        _selectedGameId.value = gameId
+    }
+
+    fun getGameState(gameId: String): LiveChessGameState? = _activeGames.value[gameId] ?: _spectatingGames.value[gameId]
+
+    fun isUserParticipant(gameId: String): Boolean = _activeGames.value.containsKey(gameId)
+
+    fun isSpectating(gameId: String): Boolean = _spectatingGames.value.containsKey(gameId)
+
+    fun clearAll() {
+        _activeGames.value = emptyMap()
+        _publicGames.value = emptyList()
+        _challenges.value = emptyList()
+        _spectatingGames.value = emptyMap()
+        _completedGames.value = emptyList()
+        _broadcastStatus.value = ChessBroadcastStatus.Idle
+        _error.value = null
+        _selectedGameId.value = null
+    }
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/chess/ChessRelayFetchHelper.kt

@@ -0,0 +1,93 @@
+/**
+ * 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.chess
+
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.relay.client.INostrClient
+import com.vitorpamplona.quartz.nip01Core.relay.client.reqs.IRequestListener
+import com.vitorpamplona.quartz.nip01Core.relay.client.single.newSubId
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.withTimeoutOrNull
+import java.util.concurrent.ConcurrentHashMap
+
+/**
+ * One-shot relay fetch helper for chess events.
+ *
+ * Follows the existing INostrClient + IRequestListener + Channel pattern
+ * from quartz (see NostrClientSingleDownloadExt.kt).
+ *
+ * Each fetch opens a subscription, collects events until EOSE from all relays,
+ * then closes and returns the collected events. The subscription is transient —
+ * no state is cached between fetches.
+ */
+class ChessRelayFetchHelper(
+    private val client: INostrClient,
+) {
+    /**
+     * Fetch events matching filters from relays, waiting for EOSE.
+     *
+     * @param filters Map of relay → filter list (same format as INostrClient.openReqSubscription)
+     * @param timeoutMs Max time to wait for all relays to send EOSE
+     * @return Deduplicated list of events received before timeout/EOSE
+     */
+    suspend fun fetchEvents(
+        filters: Map<NormalizedRelayUrl, List<Filter>>,
+        timeoutMs: Long = 30_000,
+    ): List<Event> {
+        if (filters.isEmpty()) return emptyList()
+
+        val events = ConcurrentHashMap<String, Event>()
+        val relayCount = filters.keys.size
+        val eoseReceived = ConcurrentHashMap.newKeySet<NormalizedRelayUrl>()
+        val allEose = CompletableDeferred<Unit>()
+        val subId = newSubId()
+
+        val listener =
+            object : IRequestListener {
+                override fun onEvent(
+                    event: Event,
+                    isLive: Boolean,
+                    relay: NormalizedRelayUrl,
+                    forFilters: List<Filter>?,
+                ) {
+                    events[event.id] = event
+                }
+
+                override fun onEose(
+                    relay: NormalizedRelayUrl,
+                    forFilters: List<Filter>?,
+                ) {
+                    eoseReceived.add(relay)
+                    if (eoseReceived.size >= relayCount) {
+                        allEose.complete(Unit)
+                    }
+                }
+            }
+
+        client.openReqSubscription(subId, filters, listener)
+        withTimeoutOrNull(timeoutMs) { allEose.await() }
+        client.close(subId)
+
+        return events.values.toList()
+    }
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/chess/IUserMetadataProvider.kt

@@ -0,0 +1,33 @@
+/**
+ * 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.chess
+
+/**
+ * Platform-specific metadata provider for enriching chess challenges with display info.
+ *
+ * Android: wraps LocalCache.users[pubkey].info
+ * Desktop: wraps UserMetadataCache
+ */
+interface IUserMetadataProvider {
+    fun getDisplayName(pubkey: String): String
+
+    fun getPictureUrl(pubkey: String): String?
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/chess/InteractiveChessBoard.kt

@@ -24,6 +24,7 @@ import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
 import androidx.compose.foundation.border
 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
@@ -31,8 +32,11 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.Card
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -69,15 +73,27 @@ fun InteractiveChessBoard(
     boardSize: Dp = 400.dp,
     flipped: Boolean = false,
     playerColor: ChessColor? = null, // null = allow both (for local play)
+    positionVersion: Int = 0, // External trigger for position refresh (e.g. moveHistory.size)
     onMoveMade: (from: String, to: String, san: String) -> Unit = { _, _, _ -> },
 ) {
-    // Track move count to trigger recomposition when board changes
-    var moveCount by remember { mutableStateOf(0) }
-    val position = remember(engine, moveCount) { engine.getPosition() }
-    val sideToMove = remember(engine, moveCount) { engine.getSideToMove() }
+    // Track local move count + external version to trigger recomposition when board changes
+    var localMoveCount by remember { mutableStateOf(0) }
+    val effectiveVersion = localMoveCount + positionVersion
+    val position = remember(engine, effectiveVersion) { engine.getPosition() }
+    val sideToMove = remember(engine, effectiveVersion) { engine.getSideToMove() }
     var selectedSquare by remember { mutableStateOf<Pair<Int, Int>?>(null) }
     var legalMoves by remember { mutableStateOf<List<String>>(emptyList()) }
 
+    // Pawn promotion state
+    var pendingPromotion by remember { mutableStateOf<PendingPromotion?>(null) }
+
+    // Clear stale selection when position changes externally (e.g. opponent move)
+    LaunchedEffect(positionVersion) {
+        selectedSquare = null
+        legalMoves = emptyList()
+        pendingPromotion = null
+    }
+
     // Can only interact if it's your turn (or playerColor is null for local play)
     val canInteract = playerColor == null || sideToMove == playerColor
 
@@ -87,66 +103,118 @@ fun InteractiveChessBoard(
     val rankRange = if (flipped) (0..7) else (7 downTo 0)
     val fileRange = if (flipped) (7 downTo 0) else (0..7)
 
-    Column(modifier = modifier.size(boardSize)) {
-        for (rank in rankRange) {
-            Row {
-                for (file in fileRange) {
-                    val piece = position.pieceAt(file, rank)
-                    val isLightSquare = (rank + file) % 2 == 0
-                    val square = fileRankToSquare(file, rank)
-                    val isSelected = selectedSquare == (file to rank)
-                    val isLegalMove = legalMoves.contains(square)
+    Box(modifier = modifier.size(boardSize)) {
+        Column(modifier = Modifier.fillMaxSize()) {
+            for (rank in rankRange) {
+                Row {
+                    for (file in fileRange) {
+                        val piece = position.pieceAt(file, rank)
+                        val isLightSquare = (rank + file) % 2 == 0
+                        val square = fileRankToSquare(file, rank)
+                        val isSelected = selectedSquare == (file to rank)
+                        val isLegalMove = legalMoves.contains(square)
 
-                    val showCoord = if (flipped) rank == 7 else rank == 0
+                        val showCoord = if (flipped) rank == 7 else rank == 0
 
-                    InteractiveChessSquare(
-                        piece = piece,
-                        isLight = isLightSquare,
-                        size = squareSize,
-                        isSelected = isSelected,
-                        isLegalMove = isLegalMove,
-                        showCoordinate = showCoord,
-                        file = file,
-                        rank = rank,
-                        onClick = {
-                            if (!canInteract) return@InteractiveChessSquare
+                        InteractiveChessSquare(
+                            piece = piece,
+                            isLight = isLightSquare,
+                            size = squareSize,
+                            isSelected = isSelected,
+                            isLegalMove = isLegalMove,
+                            showCoordinate = showCoord,
+                            file = file,
+                            rank = rank,
+                            onClick = {
+                                if (!canInteract || pendingPromotion != null) return@InteractiveChessSquare
 
-                            if (selectedSquare != null) {
-                                // Attempt to make move - validate first, don't actually make it
-                                val from = fileRankToSquare(selectedSquare!!.first, selectedSquare!!.second)
-                                val to = square
+                                if (selectedSquare != null) {
+                                    // Attempt to make move - validate first, don't actually make it
+                                    val from = fileRankToSquare(selectedSquare!!.first, selectedSquare!!.second)
+                                    val to = square
 
-                                if (legalMoves.contains(to)) {
-                                    // Valid move - callback will make the actual move
-                                    selectedSquare = null
-                                    legalMoves = emptyList()
-                                    // Pass empty san - callback will get it from makeMove result
-                                    onMoveMade(from, to, "")
-                                    moveCount++ // Trigger recomposition after move is made
+                                    if (legalMoves.contains(to)) {
+                                        // Check if this is a pawn promotion move
+                                        val fromRank = selectedSquare!!.second
+                                        val toRank = rank
+                                        val movingPiece = position.pieceAt(selectedSquare!!.first, fromRank)
+                                        val isPromotion =
+                                            movingPiece?.type == PieceType.PAWN &&
+                                                (toRank == 7 || toRank == 0)
+
+                                        if (isPromotion) {
+                                            // Show promotion dialog
+                                            pendingPromotion =
+                                                PendingPromotion(
+                                                    from = from,
+                                                    to = to,
+                                                    file = file,
+                                                    rank = toRank,
+                                                    color = sideToMove,
+                                                )
+                                        } else {
+                                            // Valid move - callback will make the actual move
+                                            selectedSquare = null
+                                            legalMoves = emptyList()
+                                            // Pass empty san - callback will get it from makeMove result
+                                            onMoveMade(from, to, "")
+                                            localMoveCount++ // Trigger recomposition after move is made
+                                        }
+                                    } else {
+                                        // Not a legal move target - try selecting this square instead
+                                        val validColor = playerColor ?: sideToMove
+                                        if (piece != null && piece.color == validColor) {
+                                            selectedSquare = file to rank
+                                            legalMoves = engine.getLegalMovesFrom(square)
+                                        } else {
+                                            selectedSquare = null
+                                            legalMoves = emptyList()
+                                        }
+                                    }
                                 } else {
-                                    // Not a legal move target - try selecting this square instead
+                                    // Select piece - only allow selecting player's pieces
                                     val validColor = playerColor ?: sideToMove
                                     if (piece != null && piece.color == validColor) {
                                         selectedSquare = file to rank
                                         legalMoves = engine.getLegalMovesFrom(square)
-                                    } else {
-                                        selectedSquare = null
-                                        legalMoves = emptyList()
                                     }
                                 }
-                            } else {
-                                // Select piece - only allow selecting player's pieces
-                                val validColor = playerColor ?: sideToMove
-                                if (piece != null && piece.color == validColor) {
-                                    selectedSquare = file to rank
-                                    legalMoves = engine.getLegalMovesFrom(square)
-                                }
-                            }
-                        },
-                    )
+                            },
+                        )
+                    }
                 }
             }
         }
+
+        // Promotion dialog overlay
+        pendingPromotion?.let { promo ->
+            PromotionPicker(
+                color = promo.color,
+                squareSize = squareSize,
+                onPieceSelected = { pieceType ->
+                    // Make the move with promotion
+                    val promotionSuffix =
+                        when (pieceType) {
+                            PieceType.QUEEN -> "q"
+                            PieceType.ROOK -> "r"
+                            PieceType.BISHOP -> "b"
+                            PieceType.KNIGHT -> "n"
+                            else -> "q"
+                        }
+                    selectedSquare = null
+                    legalMoves = emptyList()
+                    pendingPromotion = null
+                    // Include promotion in the 'to' square for the callback
+                    onMoveMade(promo.from, promo.to + promotionSuffix, "")
+                    localMoveCount++
+                },
+                onDismiss = {
+                    pendingPromotion = null
+                    selectedSquare = null
+                    legalMoves = emptyList()
+                },
+            )
+        }
     }
 }
 
@@ -254,3 +322,71 @@ private fun ChessPiece.toImageVector(): ImageVector {
         PieceType.PAWN -> if (white) ChessPieceVectors.WhitePawn else ChessPieceVectors.BlackPawn
     }
 }
+
+/**
+ * Data class for pending pawn promotion
+ */
+private data class PendingPromotion(
+    val from: String,
+    val to: String,
+    val file: Int,
+    val rank: Int,
+    val color: ChessColor,
+)
+
+/**
+ * Promotion piece picker overlay
+ */
+@Composable
+private fun PromotionPicker(
+    color: ChessColor,
+    squareSize: Dp,
+    onPieceSelected: (PieceType) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val isWhite = color == ChessColor.WHITE
+    val promotionPieces =
+        listOf(
+            PieceType.QUEEN to if (isWhite) ChessPieceVectors.WhiteQueen else ChessPieceVectors.BlackQueen,
+            PieceType.ROOK to if (isWhite) ChessPieceVectors.WhiteRook else ChessPieceVectors.BlackRook,
+            PieceType.BISHOP to if (isWhite) ChessPieceVectors.WhiteBishop else ChessPieceVectors.BlackBishop,
+            PieceType.KNIGHT to if (isWhite) ChessPieceVectors.WhiteKnight else ChessPieceVectors.BlackKnight,
+        )
+
+    // Semi-transparent overlay
+    Box(
+        modifier =
+            Modifier
+                .fillMaxSize()
+                .background(Color.Black.copy(alpha = 0.5f))
+                .clickable { onDismiss() },
+        contentAlignment = Alignment.Center,
+    ) {
+        Card(
+            shape = RoundedCornerShape(8.dp),
+            modifier = Modifier.clickable { /* prevent dismiss */ },
+        ) {
+            Row(
+                modifier = Modifier.padding(8.dp),
+                horizontalArrangement = Arrangement.spacedBy(4.dp),
+            ) {
+                promotionPieces.forEach { (pieceType, icon) ->
+                    Box(
+                        modifier =
+                            Modifier
+                                .size(squareSize)
+                                .background(Color(0xFFF0D9B5), RoundedCornerShape(4.dp))
+                                .clickable { onPieceSelected(pieceType) },
+                        contentAlignment = Alignment.Center,
+                    ) {
+                        Image(
+                            imageVector = icon,
+                            contentDescription = pieceType.name,
+                            modifier = Modifier.fillMaxSize().padding(4.dp),
+                        )
+                    }
+                }
+            }
+        }
+    }
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/chess/LiveChessGame.kt

@@ -54,6 +54,7 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.min
 import androidx.compose.ui.window.Dialog
 import com.vitorpamplona.quartz.nip64Chess.ChessEngine
+import com.vitorpamplona.quartz.nip64Chess.ChessGameNameGenerator
 import com.vitorpamplona.quartz.nip64Chess.Color
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameState
 
@@ -189,6 +190,9 @@ fun LiveChessGameScreen(
     val currentPosition by gameState.currentPosition.collectAsState()
     val moveHistory by gameState.moveHistory.collectAsState()
 
+    // Pending challenges and spectators cannot make moves
+    val canMakeMoves = !gameState.isSpectator && !gameState.isPendingChallenge
+
     BoxWithConstraints(
         modifier = modifier.fillMaxSize(),
     ) {
@@ -212,15 +216,23 @@ fun LiveChessGameScreen(
                 opponentName = opponentName,
                 playerColor = gameState.playerColor,
                 currentTurn = currentPosition.activeColor,
+                isSpectator = gameState.isSpectator,
+                isPendingChallenge = gameState.isPendingChallenge,
             )
 
-            // Interactive chess board - flip when playing black
+            // Interactive chess board - flip when playing black (spectators see from white's view)
             // Auto-sized to fit available space
             InteractiveChessBoard(
                 engine = gameState.engine,
                 boardSize = boardSize,
-                flipped = gameState.playerColor == Color.BLACK,
-                onMoveMade = onMoveMade,
+                flipped = !gameState.isSpectator && gameState.playerColor == Color.BLACK,
+                positionVersion = moveHistory.size,
+                onMoveMade =
+                    if (canMakeMoves) {
+                        onMoveMade
+                    } else {
+                        { _, _, _ -> } // No-op for spectators and pending challenges
+                    },
             )
 
             // Move history (scrollable) - observed from state flow
@@ -228,11 +240,12 @@ fun LiveChessGameScreen(
                 moves = moveHistory,
             )
 
-            // Game controls
-            GameControls(
-                onResign = onResign,
-                onOfferDraw = onOfferDraw,
-            )
+            // Show appropriate controls based on game state
+            when {
+                gameState.isPendingChallenge -> PendingChallengeInfo()
+                gameState.isSpectator -> SpectatorInfo()
+                else -> GameControls(onResign = onResign, onOfferDraw = onOfferDraw)
+            }
         }
     }
 }
@@ -291,6 +304,7 @@ fun LiveChessGameScreen(
                 engine = engine,
                 boardSize = boardSize,
                 flipped = playerColor == Color.BLACK,
+                positionVersion = engine.getMoveHistory().size,
                 onMoveMade = onMoveMade,
             )
 
@@ -317,45 +331,147 @@ private fun GameInfoHeader(
     opponentName: String,
     playerColor: Color,
     currentTurn: Color,
+    isSpectator: Boolean = false,
+    isPendingChallenge: Boolean = false,
 ) {
+    // Extract human-readable game name if available
+    val gameName =
+        remember(gameId) {
+            ChessGameNameGenerator.extractDisplayName(gameId)
+        }
+
     Column(
         modifier = Modifier.fillMaxWidth(),
         horizontalAlignment = Alignment.CenterHorizontally,
     ) {
+        // Show readable name prominently if available
+        if (gameName != null) {
+            Text(
+                text = gameName,
+                style = MaterialTheme.typography.titleMedium,
+                fontWeight = FontWeight.Bold,
+                color = MaterialTheme.colorScheme.primary,
+            )
+        }
+
         Text(
-            text = "Game: ${gameId.take(8)}...",
+            text = if (gameName != null) gameId.take(16) else "Game: ${gameId.take(8)}...",
             style = MaterialTheme.typography.labelSmall,
             color = MaterialTheme.colorScheme.onSurfaceVariant,
         )
 
-        Text(
-            text = "vs $opponentName",
-            style = MaterialTheme.typography.titleMedium,
-            fontWeight = FontWeight.Bold,
-        )
+        when {
+            isPendingChallenge -> {
+                Text(
+                    text = "Challenge Pending",
+                    style = MaterialTheme.typography.titleMedium,
+                    fontWeight = FontWeight.Bold,
+                    color = MaterialTheme.colorScheme.secondary,
+                )
 
-        Text(
-            text = "You are playing ${if (playerColor == Color.WHITE) "White" else "Black"}",
-            style = MaterialTheme.typography.bodyMedium,
-        )
+                Text(
+                    text = "You are playing ${if (playerColor == Color.WHITE) "White" else "Black"}",
+                    style = MaterialTheme.typography.bodyMedium,
+                )
 
-        val turnText =
-            if (currentTurn == playerColor) {
-                "Your turn"
-            } else {
-                "Opponent's turn"
+                Text(
+                    text = if (opponentName.isNotEmpty()) "Waiting for $opponentName" else "Open challenge",
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
             }
+            isSpectator -> {
+                Text(
+                    text = "Spectating",
+                    style = MaterialTheme.typography.titleMedium,
+                    fontWeight = FontWeight.Bold,
+                    color = MaterialTheme.colorScheme.tertiary,
+                )
 
+                val turnText = "${if (currentTurn == Color.WHITE) "White" else "Black"}'s turn"
+                Text(
+                    text = turnText,
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+            else -> {
+                Text(
+                    text = "vs $opponentName",
+                    style = MaterialTheme.typography.titleMedium,
+                    fontWeight = FontWeight.Bold,
+                )
+
+                Text(
+                    text = "You are playing ${if (playerColor == Color.WHITE) "White" else "Black"}",
+                    style = MaterialTheme.typography.bodyMedium,
+                )
+
+                val turnText =
+                    if (currentTurn == playerColor) {
+                        "Your turn"
+                    } else {
+                        "Opponent's turn"
+                    }
+
+                Text(
+                    text = turnText,
+                    style = MaterialTheme.typography.bodyMedium,
+                    color =
+                        if (currentTurn == playerColor) {
+                            MaterialTheme.colorScheme.primary
+                        } else {
+                            MaterialTheme.colorScheme.onSurfaceVariant
+                        },
+                    fontWeight = if (currentTurn == playerColor) FontWeight.Bold else FontWeight.Normal,
+                )
+            }
+        }
+    }
+}
+
+/**
+ * Info banner shown when spectating a game
+ */
+@Composable
+private fun SpectatorInfo() {
+    Box(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .background(
+                    MaterialTheme.colorScheme.tertiaryContainer.copy(alpha = 0.5f),
+                    RoundedCornerShape(8.dp),
+                ).padding(12.dp),
+        contentAlignment = Alignment.Center,
+    ) {
         Text(
-            text = turnText,
+            text = "Watching game - spectator mode",
             style = MaterialTheme.typography.bodyMedium,
-            color =
-                if (currentTurn == playerColor) {
-                    MaterialTheme.colorScheme.primary
-                } else {
-                    MaterialTheme.colorScheme.onSurfaceVariant
-                },
-            fontWeight = if (currentTurn == playerColor) FontWeight.Bold else FontWeight.Normal,
+            color = MaterialTheme.colorScheme.onTertiaryContainer,
+        )
+    }
+}
+
+/**
+ * Info banner shown when viewing a pending challenge
+ */
+@Composable
+private fun PendingChallengeInfo() {
+    Box(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .background(
+                    MaterialTheme.colorScheme.secondaryContainer.copy(alpha = 0.5f),
+                    RoundedCornerShape(8.dp),
+                ).padding(12.dp),
+        contentAlignment = Alignment.Center,
+    ) {
+        Text(
+            text = "Waiting for opponent to accept challenge",
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSecondaryContainer,
         )
     }
 }

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/chess/subscription/ChessFilterBuilder.kt

@@ -0,0 +1,292 @@
+/**
+ * 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.chess.subscription
+
+import com.vitorpamplona.quartz.nip01Core.relay.client.pool.RelayBasedFilter
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameAcceptEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameEndEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessMoveEvent
+import com.vitorpamplona.quartz.utils.TimeUtils
+
+/**
+ * Shared filter builder for chess subscriptions.
+ * Used by both Android and Desktop to ensure identical subscription behavior.
+ *
+ * Builds 4 types of filters:
+ * 1. Personal filters - Events tagged with user's pubkey
+ * 2. Challenge filters - All challenges (like jesterui pattern)
+ * 3. Active game filters - Game-specific move/end subscriptions
+ * 4. Recent game filters - For spectating discovery (7 day window)
+ */
+object ChessFilterBuilder {
+    /** Challenge and accept event kinds (for lobby display) */
+    private val CHALLENGE_KINDS =
+        listOf(
+            LiveChessGameChallengeEvent.KIND,
+            LiveChessGameAcceptEvent.KIND,
+        )
+
+    /** Move and end event kinds (for active games) */
+    private val GAME_EVENT_KINDS =
+        listOf(
+            LiveChessMoveEvent.KIND,
+            LiveChessGameEndEvent.KIND,
+        )
+
+    /** All chess event kinds */
+    private val ALL_CHESS_KINDS = CHALLENGE_KINDS + GAME_EVENT_KINDS
+
+    /**
+     * Build all chess filters for a given subscription state.
+     * This is the main entry point - platforms call this to get filters.
+     *
+     * @param state The current subscription state with user info and active games
+     * @param sinceForRelay Function to get cached EOSE time for a relay (null if no cache)
+     * @return List of relay-specific filters to subscribe with
+     */
+    fun buildAllFilters(
+        state: ChessSubscriptionState,
+        sinceForRelay: (NormalizedRelayUrl) -> Long?,
+    ): List<RelayBasedFilter> {
+        val filters = mutableListOf<RelayBasedFilter>()
+        val now = TimeUtils.now()
+
+        // Filter 1: Personal events (challenges to us, moves in our games)
+        filters.addAll(
+            buildPersonalFilters(state.userPubkey, state.relays, sinceForRelay, now),
+        )
+
+        // Filter 2: All challenges (for lobby display)
+        filters.addAll(
+            buildChallengeFilters(state.relays, sinceForRelay, now),
+        )
+
+        // Filter 3: Active game subscriptions (game-specific)
+        if (state.hasActiveGames) {
+            filters.addAll(
+                buildActiveGameFilters(
+                    state.allGameIds,
+                    state.userPubkey,
+                    state.opponentPubkeys,
+                    state.relays,
+                ),
+            )
+        }
+
+        // Filter 4: Recent game events (for spectating discovery)
+        filters.addAll(
+            buildRecentGameFilters(state.relays, sinceForRelay, now),
+        )
+
+        return filters
+    }
+
+    /**
+     * Personal events - tagged with user's pubkey.
+     * Catches: challenges directed at us, moves in our games, game ends.
+     */
+    fun buildPersonalFilters(
+        userPubkey: String,
+        relays: Set<NormalizedRelayUrl>,
+        sinceForRelay: (NormalizedRelayUrl) -> Long?,
+        now: Long = TimeUtils.now(),
+    ): List<RelayBasedFilter> {
+        val filter =
+            Filter(
+                kinds = ALL_CHESS_KINDS,
+                tags = mapOf("p" to listOf(userPubkey)),
+                limit = 100,
+            )
+
+        return relays.map { relay ->
+            val sinceTime =
+                sinceForRelay(relay)
+                    ?: (now - ChessTimeWindows.CHALLENGE_WINDOW_SECONDS)
+            RelayBasedFilter(
+                relay = relay,
+                filter = filter.copy(since = sinceTime),
+            )
+        }
+    }
+
+    /**
+     * All challenge events (like jesterui pattern).
+     * No author/tag restriction - fetch everything, filter client-side.
+     * This ensures we see open challenges and public games.
+     */
+    fun buildChallengeFilters(
+        relays: Set<NormalizedRelayUrl>,
+        sinceForRelay: (NormalizedRelayUrl) -> Long?,
+        now: Long = TimeUtils.now(),
+    ): List<RelayBasedFilter> {
+        val filter =
+            Filter(
+                kinds = CHALLENGE_KINDS,
+                limit = 100,
+            )
+
+        return relays.map { relay ->
+            val sinceTime =
+                sinceForRelay(relay)
+                    ?: (now - ChessTimeWindows.CHALLENGE_WINDOW_SECONDS)
+            RelayBasedFilter(
+                relay = relay,
+                filter = filter.copy(since = sinceTime),
+            )
+        }
+    }
+
+    /**
+     * Active game events - game-specific subscriptions.
+     * These filters ensure moves are received for games the user is playing.
+     *
+     * Note: Move d-tags are "gameId-moveNumber" so we can't filter by #d for moves.
+     * We use two strategies:
+     * 1. Filter by authors (opponent pubkeys) - catches moves they make
+     * 2. Filter by #p tag (opponent tagged us) - catches moves tagged with us
+     *
+     * End events use gameId as d-tag so we can filter those directly.
+     */
+    fun buildActiveGameFilters(
+        gameIds: Set<String>,
+        userPubkey: String,
+        opponentPubkeys: Set<String>,
+        relays: Set<NormalizedRelayUrl>,
+    ): List<RelayBasedFilter> {
+        if (gameIds.isEmpty()) return emptyList()
+
+        println("[ChessFilterBuilder] Building filters for ${gameIds.size} games, ${opponentPubkeys.size} opponents: $opponentPubkeys")
+
+        val filters = mutableListOf<RelayBasedFilter>()
+
+        // End events: filter by d-tag (gameId)
+        val endFilter =
+            Filter(
+                kinds = listOf(LiveChessGameEndEvent.KIND),
+                tags = mapOf("d" to gameIds.toList()),
+                limit = 50,
+            )
+
+        // Move events: filter by p-tag (opponent tagged us)
+        // This catches all moves for games where we're a participant
+        val moveFilterByTag =
+            Filter(
+                kinds = listOf(LiveChessMoveEvent.KIND),
+                tags = mapOf("p" to listOf(userPubkey)),
+                limit = 200,
+            )
+
+        relays.forEach { relay ->
+            filters.add(RelayBasedFilter(relay = relay, filter = endFilter))
+            filters.add(RelayBasedFilter(relay = relay, filter = moveFilterByTag))
+        }
+
+        // Move events: filter by authors (opponent pubkeys)
+        // This directly catches moves made by our opponents
+        if (opponentPubkeys.isNotEmpty()) {
+            println("[ChessFilterBuilder] Adding author filter for opponents: $opponentPubkeys")
+            val moveFilterByAuthor =
+                Filter(
+                    kinds = listOf(LiveChessMoveEvent.KIND),
+                    authors = opponentPubkeys.toList(),
+                    limit = 200,
+                )
+
+            relays.forEach { relay ->
+                filters.add(RelayBasedFilter(relay = relay, filter = moveFilterByAuthor))
+            }
+        } else {
+            println("[ChessFilterBuilder] WARNING: No opponent pubkeys provided!")
+        }
+
+        return filters
+    }
+
+    /**
+     * Recent game events for spectating discovery.
+     * Uses longer time window (7 days) to catch ongoing games.
+     */
+    fun buildRecentGameFilters(
+        relays: Set<NormalizedRelayUrl>,
+        sinceForRelay: (NormalizedRelayUrl) -> Long?,
+        now: Long = TimeUtils.now(),
+    ): List<RelayBasedFilter> {
+        val filter =
+            Filter(
+                kinds = GAME_EVENT_KINDS,
+                limit = 100,
+            )
+
+        return relays.map { relay ->
+            val sinceTime =
+                sinceForRelay(relay)
+                    ?: (now - ChessTimeWindows.GAME_EVENT_WINDOW_SECONDS)
+            RelayBasedFilter(
+                relay = relay,
+                filter = filter.copy(since = sinceTime),
+            )
+        }
+    }
+
+    // ===================================================
+    // Simple filters for one-shot fetches (ChessRelayFetcher)
+    // ===================================================
+
+    /**
+     * Filter for all events related to a specific game.
+     * Used for one-shot fetch when loading a game.
+     */
+    fun gameEventsFilter(gameId: String): Filter =
+        Filter(
+            kinds = ALL_CHESS_KINDS + listOf(com.vitorpamplona.quartz.nip64Chess.LiveChessDrawOfferEvent.KIND),
+            tags = mapOf("d" to listOf(gameId)),
+            limit = 500,
+        )
+
+    /**
+     * Filter for challenge events in the last 24 hours.
+     * Used for one-shot fetch to populate lobby.
+     */
+    fun challengesFilter(userPubkey: String): Filter {
+        val now = TimeUtils.now()
+        return Filter(
+            kinds = CHALLENGE_KINDS,
+            since = now - ChessTimeWindows.CHALLENGE_WINDOW_SECONDS,
+            limit = 100,
+        )
+    }
+
+    /**
+     * Filter for recent game activity for spectating discovery.
+     * Fetches move events from the last 7 days.
+     */
+    fun recentGamesFilter(): Filter {
+        val now = TimeUtils.now()
+        return Filter(
+            kinds = ALL_CHESS_KINDS,
+            since = now - ChessTimeWindows.GAME_EVENT_WINDOW_SECONDS,
+            limit = 200,
+        )
+    }
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/chess/subscription/ChessSubscriptionController.kt

@@ -0,0 +1,69 @@
+/**
+ * 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.chess.subscription
+
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * Interface for platform-specific chess subscription management.
+ *
+ * Implementations handle the actual relay subscription mechanics while
+ * using [ChessFilterBuilder] for consistent filter construction.
+ *
+ * Key responsibilities:
+ * - Subscribe/unsubscribe to chess events on relays
+ * - Update filters when active games change
+ * - Track EOSE (End of Stored Events) per relay for efficient re-subscription
+ */
+interface ChessSubscriptionController {
+    /** Current subscription state, null if not subscribed */
+    val currentState: StateFlow<ChessSubscriptionState?>
+
+    /**
+     * Subscribe to chess events with the given state.
+     * Replaces any existing subscription.
+     */
+    fun subscribe(state: ChessSubscriptionState)
+
+    /** Unsubscribe from all chess events */
+    fun unsubscribe()
+
+    /**
+     * Update active game IDs and refresh subscription filters.
+     * This is the key method for dynamic subscription updates.
+     *
+     * When a game starts or ends, call this to update the filters
+     * so moves are properly received for active games.
+     *
+     * @param activeGameIds Game IDs the user is actively playing
+     * @param spectatingGameIds Game IDs the user is watching (optional)
+     */
+    fun updateActiveGames(
+        activeGameIds: Set<String>,
+        spectatingGameIds: Set<String> = emptySet(),
+    )
+
+    /**
+     * Force refresh all filters from relays.
+     * Clears EOSE cache so full history is re-fetched.
+     */
+    fun forceRefresh()
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/chess/subscription/ChessSubscriptionState.kt

@@ -0,0 +1,70 @@
+/**
+ * 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.chess.subscription
+
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
+
+/**
+ * Immutable state for chess relay subscriptions.
+ * Used to generate subscription filters and track subscription identity.
+ *
+ * When any of these values change, a new subscription should be created
+ * with updated filters.
+ */
+@Immutable
+data class ChessSubscriptionState(
+    /** User's public key (hex) for filtering personal events */
+    val userPubkey: String,
+    /** Set of relays to subscribe to */
+    val relays: Set<NormalizedRelayUrl>,
+    /** Game IDs the user is actively playing */
+    val activeGameIds: Set<String> = emptySet(),
+    /** Game IDs the user is spectating */
+    val spectatingGameIds: Set<String> = emptySet(),
+    /** Opponent pubkeys for active games (to filter their moves) */
+    val opponentPubkeys: Set<String> = emptySet(),
+) {
+    /**
+     * Unique subscription ID that changes when game IDs change.
+     * Used for:
+     * - Subscription deduplication
+     * - EOSE cache keying
+     * - Detecting when filters need to be refreshed
+     */
+    fun subscriptionId(): String =
+        buildString {
+            append("chess-")
+            append(userPubkey.take(8))
+            if (allGameIds.isNotEmpty()) {
+                append("-g")
+                append(allGameIds.sorted().hashCode())
+            }
+        }
+
+    /** All game IDs requiring move subscriptions (active + spectating) */
+    val allGameIds: Set<String>
+        get() = activeGameIds + spectatingGameIds
+
+    /** True if user has any active or spectating games */
+    val hasActiveGames: Boolean
+        get() = allGameIds.isNotEmpty()
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/chess/subscription/ChessTimeWindows.kt

@@ -0,0 +1,40 @@
+/**
+ * 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.chess.subscription
+
+/**
+ * Shared time window constants for chess subscriptions.
+ * Used by both Android and Desktop to ensure consistent behavior.
+ */
+object ChessTimeWindows {
+    /**
+     * 24 hours - challenges older than this are considered expired.
+     * Used for challenge and accept event filters.
+     */
+    const val CHALLENGE_WINDOW_SECONDS = 24 * 60 * 60L
+
+    /**
+     * 7 days - default lookback for game events when no EOSE cache exists.
+     * This prevents loading ancient game history on first connection
+     * while still allowing recovery of recent games.
+     */
+    const val GAME_EVENT_WINDOW_SECONDS = 7 * 24 * 60 * 60L
+}

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/chess/ChessScreen.kt

@@ -69,9 +69,10 @@ import com.vitorpamplona.amethyst.commons.data.UserMetadataCache
 import com.vitorpamplona.amethyst.commons.ui.components.UserAvatar
 import com.vitorpamplona.amethyst.desktop.account.AccountState
 import com.vitorpamplona.amethyst.desktop.network.DesktopRelayConnectionManager
-import com.vitorpamplona.amethyst.desktop.subscriptions.createChessSubscription
+import com.vitorpamplona.amethyst.desktop.subscriptions.createChessSubscriptionWithGames
 import com.vitorpamplona.amethyst.desktop.subscriptions.createMetadataListSubscription
 import com.vitorpamplona.amethyst.desktop.subscriptions.rememberSubscription
+import com.vitorpamplona.quartz.nip64Chess.ChessGameNameGenerator
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
 
 /**
@@ -91,14 +92,26 @@ fun ChessScreen(
     val relayStatuses by relayManager.relayStatuses.collectAsState()
     val refreshKey by viewModel.refreshKey.collectAsState()
     val isLoading by viewModel.isLoading.collectAsState()
+    val activeGames by viewModel.activeGames.collectAsState()
 
-    // Subscribe to chess events from relays (re-subscribes when refreshKey changes)
-    rememberSubscription(relayStatuses, account, refreshKey, relayManager = relayManager) {
+    // Extract opponent pubkeys from active games for move filtering
+    val opponentPubkeys =
+        remember(activeGames) {
+            val pubkeys = activeGames.values.map { it.opponentPubkey }.toSet()
+            println("[ChessScreen] Active games: ${activeGames.keys}, Opponent pubkeys: $pubkeys")
+            pubkeys
+        }
+
+    // Subscribe to chess events from relays
+    // Re-subscribes when relays, refreshKey, or active games change
+    rememberSubscription(relayStatuses, account, refreshKey, activeGames.keys, opponentPubkeys, relayManager = relayManager) {
         val configuredRelays = relayStatuses.keys
         if (configuredRelays.isNotEmpty()) {
-            createChessSubscription(
+            createChessSubscriptionWithGames(
                 relays = configuredRelays,
                 userPubkey = account.pubKeyHex,
+                activeGameIds = activeGames.keys,
+                opponentPubkeys = opponentPubkeys,
                 onEvent = { event, _, _, _ ->
                     viewModel.handleIncomingEvent(event)
                 },
@@ -128,7 +141,6 @@ fun ChessScreen(
         }
     }
 
-    val activeGames by viewModel.activeGames.collectAsState()
     val challenges by viewModel.challenges.collectAsState()
     val completedGames by viewModel.completedGames.collectAsState()
     // Observe metadata changes to trigger recomposition
@@ -280,7 +292,7 @@ private fun ChessLobby(
                 )
             }
 
-            items(activeGames.entries.toList(), key = { it.key }) { (gameId, state) ->
+            items(activeGames.entries.toList(), key = { "active-${it.key}" }) { (gameId, state) ->
                 ActiveGameCard(
                     gameId = gameId,
                     opponentPubkey = state.opponentPubkey,
@@ -375,7 +387,10 @@ private fun ChessLobby(
                 )
             }
 
-            items(completedGames.take(10), key = { it.gameId }) { game ->
+            items(
+                completedGames.distinctBy { it.gameId }.take(10),
+                key = { "completed-${it.gameId}-${it.completedAt}" },
+            ) { game ->
                 CompletedGameCard(
                     game = game,
                     userPubkey = userPubkey,
@@ -428,6 +443,12 @@ private fun ActiveGameCard(
     isYourTurn: Boolean,
     onClick: () -> Unit,
 ) {
+    // Extract human-readable game name if available
+    val gameName =
+        remember(gameId) {
+            ChessGameNameGenerator.extractDisplayName(gameId) ?: gameId.take(12)
+        }
+
     Card(
         modifier = Modifier.fillMaxWidth().clickable(onClick = onClick),
         border =
@@ -453,14 +474,14 @@ private fun ActiveGameCard(
                 )
                 Column {
                     Text(
-                        "vs $opponentName",
-                        style = MaterialTheme.typography.bodyLarge,
-                        fontWeight = FontWeight.Medium,
+                        gameName,
+                        style = MaterialTheme.typography.titleSmall,
+                        fontWeight = FontWeight.Bold,
+                        color = MaterialTheme.colorScheme.primary,
                     )
                     Text(
-                        "Game: ${gameId.take(12)}...",
-                        style = MaterialTheme.typography.bodySmall,
-                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        "vs $opponentName",
+                        style = MaterialTheme.typography.bodyMedium,
                     )
                 }
             }
@@ -685,6 +706,7 @@ private fun DesktopChessGameLayout(
                 boardSize = 520.dp,
                 flipped = playerColor == com.vitorpamplona.quartz.nip64Chess.Color.BLACK,
                 playerColor = playerColor,
+                positionVersion = moveHistory.size,
                 onMoveMade = onMoveMade,
             )
         }
@@ -698,6 +720,12 @@ private fun DesktopChessGameLayout(
                     .verticalScroll(rememberScrollState()),
             verticalArrangement = Arrangement.spacedBy(16.dp),
         ) {
+            // Extract human-readable game name
+            val gameName =
+                remember(gameId) {
+                    ChessGameNameGenerator.extractDisplayName(gameId)
+                }
+
             // Game info card
             Card(
                 modifier = Modifier.fillMaxWidth(),
@@ -706,11 +734,21 @@ private fun DesktopChessGameLayout(
                     modifier = Modifier.padding(16.dp),
                     verticalArrangement = Arrangement.spacedBy(8.dp),
                 ) {
-                    Text(
-                        "Game Info",
-                        style = MaterialTheme.typography.titleMedium,
-                        fontWeight = FontWeight.Bold,
-                    )
+                    // Show readable game name if available
+                    if (gameName != null) {
+                        Text(
+                            gameName,
+                            style = MaterialTheme.typography.titleLarge,
+                            fontWeight = FontWeight.Bold,
+                            color = MaterialTheme.colorScheme.primary,
+                        )
+                    } else {
+                        Text(
+                            "Game Info",
+                            style = MaterialTheme.typography.titleMedium,
+                            fontWeight = FontWeight.Bold,
+                        )
+                    }
 
                     Row(
                         verticalAlignment = Alignment.CenterVertically,

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/chess/DesktopChessAdapter.kt

@@ -0,0 +1,432 @@
+/**
+ * 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.desktop.chess
+
+import com.vitorpamplona.amethyst.commons.chess.ChessEventPublisher
+import com.vitorpamplona.amethyst.commons.chess.ChessRelayFetchHelper
+import com.vitorpamplona.amethyst.commons.chess.ChessRelayFetcher
+import com.vitorpamplona.amethyst.commons.chess.IUserMetadataProvider
+import com.vitorpamplona.amethyst.commons.chess.RelayGameSummary
+import com.vitorpamplona.amethyst.commons.chess.subscription.ChessFilterBuilder
+import com.vitorpamplona.amethyst.commons.data.UserMetadataCache
+import com.vitorpamplona.amethyst.desktop.account.AccountState
+import com.vitorpamplona.amethyst.desktop.network.DesktopRelayConnectionManager
+import com.vitorpamplona.quartz.nip64Chess.ChessGameEnd
+import com.vitorpamplona.quartz.nip64Chess.ChessGameEvents
+import com.vitorpamplona.quartz.nip64Chess.ChessMoveEvent
+import com.vitorpamplona.quartz.nip64Chess.Color
+import com.vitorpamplona.quartz.nip64Chess.LiveChessDrawOfferEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameAcceptEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessGameEndEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessMoveEvent
+
+/**
+ * Desktop implementation of ChessEventPublisher.
+ * Wraps account.signer.sign() + relayManager.broadcastToAll() for event publishing.
+ */
+class DesktopChessPublisher(
+    private val account: AccountState.LoggedIn,
+    private val relayManager: DesktopRelayConnectionManager,
+) : ChessEventPublisher {
+    override suspend fun publishChallenge(
+        gameId: String,
+        playerColor: Color,
+        opponentPubkey: String?,
+        timeControl: String?,
+    ): Boolean =
+        try {
+            val template =
+                LiveChessGameChallengeEvent.build(
+                    gameId = gameId,
+                    playerColor = playerColor,
+                    opponentPubkey = opponentPubkey,
+                    timeControl = timeControl,
+                )
+            val signedEvent = account.signer.sign(template)
+            relayManager.broadcastToAll(signedEvent)
+            true
+        } catch (e: Exception) {
+            false
+        }
+
+    override suspend fun publishAccept(
+        gameId: String,
+        challengeEventId: String,
+        challengerPubkey: String,
+    ): Boolean =
+        try {
+            val template =
+                LiveChessGameAcceptEvent.build(
+                    gameId = gameId,
+                    challengeEventId = challengeEventId,
+                    challengerPubkey = challengerPubkey,
+                )
+            val signedEvent = account.signer.sign(template)
+            relayManager.broadcastToAll(signedEvent)
+            true
+        } catch (e: Exception) {
+            false
+        }
+
+    override suspend fun publishMove(move: ChessMoveEvent): Boolean =
+        try {
+            val template =
+                LiveChessMoveEvent.build(
+                    gameId = move.gameId,
+                    moveNumber = move.moveNumber,
+                    san = move.san,
+                    fen = move.fen,
+                    opponentPubkey = move.opponentPubkey,
+                )
+            val signedEvent = account.signer.sign(template)
+            relayManager.broadcastToAll(signedEvent)
+            true
+        } catch (e: Exception) {
+            false
+        }
+
+    override suspend fun publishGameEnd(gameEnd: ChessGameEnd): Boolean =
+        try {
+            val template =
+                LiveChessGameEndEvent.build(
+                    gameId = gameEnd.gameId,
+                    result = gameEnd.result,
+                    termination = gameEnd.termination,
+                    winnerPubkey = gameEnd.winnerPubkey,
+                    opponentPubkey = gameEnd.opponentPubkey,
+                    pgn = gameEnd.pgn ?: "",
+                )
+            val signedEvent = account.signer.sign(template)
+            relayManager.broadcastToAll(signedEvent)
+            true
+        } catch (e: Exception) {
+            false
+        }
+
+    override suspend fun publishDrawOffer(
+        gameId: String,
+        opponentPubkey: String,
+        message: String?,
+    ): Boolean =
+        try {
+            val template =
+                LiveChessDrawOfferEvent.build(
+                    gameId = gameId,
+                    opponentPubkey = opponentPubkey,
+                    message = message ?: "",
+                )
+            val signedEvent = account.signer.sign(template)
+            relayManager.broadcastToAll(signedEvent)
+            true
+        } catch (e: Exception) {
+            false
+        }
+
+    override fun getWriteRelayCount(): Int = relayManager.connectedRelays.value.size
+}
+
+/**
+ * Desktop implementation of ChessRelayFetcher.
+ * Uses ChessRelayFetchHelper for one-shot relay queries.
+ */
+class DesktopRelayFetcher(
+    private val relayManager: DesktopRelayConnectionManager,
+    private val userPubkey: String,
+) : ChessRelayFetcher {
+    private val fetchHelper = ChessRelayFetchHelper(relayManager.client)
+
+    override suspend fun fetchGameEvents(gameId: String): ChessGameEvents {
+        val filters = ChessFilterBuilder.gameEventsFilter(gameId)
+        val relayFilters = relayManager.connectedRelays.value.associateWith { listOf(filters) }
+
+        val events = fetchHelper.fetchEvents(relayFilters)
+
+        val challengeEvent =
+            events
+                .filterIsInstance<LiveChessGameChallengeEvent>()
+                .firstOrNull { it.gameId() == gameId }
+                ?: events
+                    .filter { it.kind == LiveChessGameChallengeEvent.KIND }
+                    .mapNotNull { event ->
+                        LiveChessGameChallengeEvent(
+                            event.id,
+                            event.pubKey,
+                            event.createdAt,
+                            event.tags,
+                            event.content,
+                            event.sig,
+                        ).takeIf { it.gameId() == gameId }
+                    }.firstOrNull()
+
+        val acceptEvent =
+            events
+                .filterIsInstance<LiveChessGameAcceptEvent>()
+                .firstOrNull { it.gameId() == gameId }
+                ?: events
+                    .filter { it.kind == LiveChessGameAcceptEvent.KIND }
+                    .mapNotNull { event ->
+                        LiveChessGameAcceptEvent(
+                            event.id,
+                            event.pubKey,
+                            event.createdAt,
+                            event.tags,
+                            event.content,
+                            event.sig,
+                        ).takeIf { it.gameId() == gameId }
+                    }.firstOrNull()
+
+        val moveEvents =
+            events
+                .filterIsInstance<LiveChessMoveEvent>()
+                .filter { it.gameId() == gameId }
+                .ifEmpty {
+                    events
+                        .filter { it.kind == LiveChessMoveEvent.KIND }
+                        .mapNotNull { event ->
+                            LiveChessMoveEvent(
+                                event.id,
+                                event.pubKey,
+                                event.createdAt,
+                                event.tags,
+                                event.content,
+                                event.sig,
+                            ).takeIf { it.gameId() == gameId }
+                        }
+                }
+
+        val endEvent =
+            events
+                .filterIsInstance<LiveChessGameEndEvent>()
+                .firstOrNull { it.gameId() == gameId }
+                ?: events
+                    .filter { it.kind == LiveChessGameEndEvent.KIND }
+                    .mapNotNull { event ->
+                        LiveChessGameEndEvent(
+                            event.id,
+                            event.pubKey,
+                            event.createdAt,
+                            event.tags,
+                            event.content,
+                            event.sig,
+                        ).takeIf { it.gameId() == gameId }
+                    }.firstOrNull()
+
+        val drawOffers =
+            events
+                .filterIsInstance<LiveChessDrawOfferEvent>()
+                .filter { it.gameId() == gameId }
+                .ifEmpty {
+                    events
+                        .filter { it.kind == LiveChessDrawOfferEvent.KIND }
+                        .mapNotNull { event ->
+                            LiveChessDrawOfferEvent(
+                                event.id,
+                                event.pubKey,
+                                event.createdAt,
+                                event.tags,
+                                event.content,
+                                event.sig,
+                            ).takeIf { it.gameId() == gameId }
+                        }
+                }
+
+        return ChessGameEvents(
+            challenge = challengeEvent,
+            accept = acceptEvent,
+            moves = moveEvents,
+            end = endEvent,
+            drawOffers = drawOffers,
+        )
+    }
+
+    override suspend fun fetchChallenges(): List<LiveChessGameChallengeEvent> {
+        val filters = ChessFilterBuilder.challengesFilter(userPubkey)
+        val relayFilters = relayManager.connectedRelays.value.associateWith { listOf(filters) }
+
+        val events = fetchHelper.fetchEvents(relayFilters)
+
+        return events
+            .filterIsInstance<LiveChessGameChallengeEvent>()
+            .ifEmpty {
+                events
+                    .filter { it.kind == LiveChessGameChallengeEvent.KIND }
+                    .map { event ->
+                        LiveChessGameChallengeEvent(
+                            event.id,
+                            event.pubKey,
+                            event.createdAt,
+                            event.tags,
+                            event.content,
+                            event.sig,
+                        )
+                    }
+            }
+    }
+
+    override suspend fun fetchRecentGames(): List<RelayGameSummary> {
+        val filters = ChessFilterBuilder.recentGamesFilter()
+        val relayFilters = relayManager.connectedRelays.value.associateWith { listOf(filters) }
+
+        val events = fetchHelper.fetchEvents(relayFilters)
+
+        // Group by game ID and create summaries
+        val gameIds =
+            events
+                .filter { it.kind == LiveChessMoveEvent.KIND }
+                .mapNotNull { event ->
+                    val move =
+                        if (event is LiveChessMoveEvent) {
+                            event
+                        } else {
+                            LiveChessMoveEvent(
+                                event.id,
+                                event.pubKey,
+                                event.createdAt,
+                                event.tags,
+                                event.content,
+                                event.sig,
+                            )
+                        }
+                    move.gameId()
+                }.distinct()
+
+        return gameIds.mapNotNull { gameId ->
+            // Find challenge and accept for this game
+            val challenge =
+                events
+                    .filter { it.kind == LiveChessGameChallengeEvent.KIND }
+                    .mapNotNull { event ->
+                        val e =
+                            if (event is LiveChessGameChallengeEvent) {
+                                event
+                            } else {
+                                LiveChessGameChallengeEvent(
+                                    event.id,
+                                    event.pubKey,
+                                    event.createdAt,
+                                    event.tags,
+                                    event.content,
+                                    event.sig,
+                                )
+                            }
+                        e.takeIf { it.gameId() == gameId }
+                    }.firstOrNull() ?: return@mapNotNull null
+
+            val accept =
+                events
+                    .filter { it.kind == LiveChessGameAcceptEvent.KIND }
+                    .mapNotNull { event ->
+                        val e =
+                            if (event is LiveChessGameAcceptEvent) {
+                                event
+                            } else {
+                                LiveChessGameAcceptEvent(
+                                    event.id,
+                                    event.pubKey,
+                                    event.createdAt,
+                                    event.tags,
+                                    event.content,
+                                    event.sig,
+                                )
+                            }
+                        e.takeIf { it.gameId() == gameId }
+                    }.firstOrNull()
+
+            val challengerColor = challenge.playerColor() ?: Color.WHITE
+            val whitePubkey =
+                if (challengerColor == Color.WHITE) {
+                    challenge.pubKey
+                } else {
+                    accept?.pubKey ?: return@mapNotNull null
+                }
+            val blackPubkey =
+                if (challengerColor == Color.BLACK) {
+                    challenge.pubKey
+                } else {
+                    accept?.pubKey ?: return@mapNotNull null
+                }
+
+            val moves =
+                events
+                    .filter { it.kind == LiveChessMoveEvent.KIND }
+                    .mapNotNull { event ->
+                        val m =
+                            if (event is LiveChessMoveEvent) {
+                                event
+                            } else {
+                                LiveChessMoveEvent(
+                                    event.id,
+                                    event.pubKey,
+                                    event.createdAt,
+                                    event.tags,
+                                    event.content,
+                                    event.sig,
+                                )
+                            }
+                        m.takeIf { it.gameId() == gameId }
+                    }
+
+            val endEvent =
+                events
+                    .filter { it.kind == LiveChessGameEndEvent.KIND }
+                    .mapNotNull { event ->
+                        val e =
+                            if (event is LiveChessGameEndEvent) {
+                                event
+                            } else {
+                                LiveChessGameEndEvent(
+                                    event.id,
+                                    event.pubKey,
+                                    event.createdAt,
+                                    event.tags,
+                                    event.content,
+                                    event.sig,
+                                )
+                            }
+                        e.takeIf { it.gameId() == gameId }
+                    }.firstOrNull()
+
+            val lastMove = moves.maxByOrNull { it.createdAt }
+
+            RelayGameSummary(
+                gameId = gameId,
+                whitePubkey = whitePubkey,
+                blackPubkey = blackPubkey,
+                moveCount = moves.size,
+                lastMoveTime = lastMove?.createdAt ?: challenge.createdAt,
+                isActive = endEvent == null,
+            )
+        }
+    }
+}
+
+/**
+ * Desktop implementation of IUserMetadataProvider.
+ * Wraps UserMetadataCache for user metadata lookup.
+ */
+class DesktopMetadataProvider(
+    private val metadataCache: UserMetadataCache,
+) : IUserMetadataProvider {
+    override fun getDisplayName(pubkey: String): String = metadataCache.getDisplayName(pubkey)
+
+    override fun getPictureUrl(pubkey: String): String? = metadataCache.getPictureUrl(pubkey)
+}

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/chess/DesktopChessViewModel.kt

@@ -20,12 +20,16 @@
  */
 package com.vitorpamplona.amethyst.desktop.chess
 
+import com.vitorpamplona.amethyst.commons.chess.ChessPollingDefaults
+import com.vitorpamplona.amethyst.commons.chess.ChessPollingDelegate
+import com.vitorpamplona.amethyst.commons.chess.subscription.ChessSubscriptionController
 import com.vitorpamplona.amethyst.commons.data.UserMetadataCache
 import com.vitorpamplona.amethyst.desktop.account.AccountState
 import com.vitorpamplona.amethyst.desktop.network.DesktopRelayConnectionManager
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.metadata.MetadataEvent
 import com.vitorpamplona.quartz.nip64Chess.ChessEngine
+import com.vitorpamplona.quartz.nip64Chess.ChessGameNameGenerator
 import com.vitorpamplona.quartz.nip64Chess.ChessMoveEvent
 import com.vitorpamplona.quartz.nip64Chess.Color
 import com.vitorpamplona.quartz.nip64Chess.GameResult
@@ -36,6 +40,7 @@ import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameEndEvent
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameState
 import com.vitorpamplona.quartz.nip64Chess.LiveChessMoveEvent
+import com.vitorpamplona.quartz.nip64Chess.PieceType
 import com.vitorpamplona.quartz.utils.TimeUtils
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -44,7 +49,6 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.launch
-import java.util.UUID
 
 /**
  * Desktop ViewModel for managing chess game state and event publishing.
@@ -106,18 +110,59 @@ class DesktopChessViewModel(
     private val pendingAccepts = mutableMapOf<String, LiveChessGameAcceptEvent>()
 
     // Track event IDs we've already processed to avoid duplicates
-    private val processedEventIds = mutableSetOf<String>()
+    // Uses ConcurrentHashMap for thread-safe check-and-add
+    private val processedEventIds =
+        java.util.concurrent.ConcurrentHashMap
+            .newKeySet<String>()
 
     // Track games currently being created to prevent race conditions
     private val gamesBeingCreated = mutableSetOf<String>()
 
+    // Subscription controller for dynamic filter updates
+    private var subscriptionController: ChessSubscriptionController? = null
+
+    // Polling delegate for periodic refresh (fallback when relay events are missed)
+    private val pollingDelegate =
+        ChessPollingDelegate(
+            config = ChessPollingDefaults.desktop,
+            scope = scope,
+            onRefreshGames = { gameIds -> refreshGamesFromRelay(gameIds) },
+            onRefreshChallenges = { /* Subscriptions handle challenges */ },
+            onCleanup = { cleanupExpiredChallenges() },
+        )
+
+    init {
+        // Start polling for move updates
+        pollingDelegate.start()
+    }
+
+    /**
+     * Set the subscription controller for dynamic filter updates.
+     * Should be called after creating the ViewModel.
+     */
+    fun setSubscriptionController(controller: ChessSubscriptionController) {
+        subscriptionController = controller
+    }
+
+    /**
+     * Notify subscription controller and polling delegate of active game changes.
+     * Call this whenever _activeGames is modified.
+     */
+    private fun notifyActiveGamesChanged() {
+        val gameIds = _activeGames.value.keys
+        subscriptionController?.updateActiveGames(
+            activeGameIds = gameIds,
+            spectatingGameIds = emptySet(),
+        )
+        pollingDelegate.setActiveGameIds(gameIds)
+    }
+
     /**
      * Process incoming chess event from relay subscription
      */
     fun handleIncomingEvent(event: Event) {
-        // Skip already processed events
-        if (processedEventIds.contains(event.id)) return
-        processedEventIds.add(event.id)
+        // Skip already processed events (atomic check-and-add)
+        if (!processedEventIds.add(event.id)) return
 
         // Check by kind since events may not be cast to specific types
         when (event.kind) {
@@ -230,8 +275,7 @@ class DesktopChessViewModel(
     }
 
     private fun handleIncomingMove(event: LiveChessMoveEvent) {
-        // Don't process our own moves
-        if (event.pubKey == account.pubKeyHex) return
+        println("[Chess] Received move event: gameId=${event.gameId()}, san=${event.san()}, moveNum=${event.moveNumber()}, from=${event.pubKey.take(8)}")
 
         val gameId = event.gameId() ?: return
         val san = event.san() ?: return
@@ -241,14 +285,25 @@ class DesktopChessViewModel(
         val gameState = _activeGames.value[gameId]
 
         if (gameState == null) {
-            // Game doesn't exist yet - buffer the move for later
+            // Game doesn't exist yet - buffer the move for later (including our own for FEN sync)
+            println("[Chess] Game $gameId not found, buffering move $san (fen for sync)")
             val moveList = pendingMoves.getOrPut(gameId) { mutableListOf() }
             moveList.add(Triple(san, fen, moveNumber))
             return
         }
 
-        if (event.pubKey != gameState.opponentPubkey) return
+        // Don't process our own moves for active games (already applied locally)
+        if (event.pubKey == account.pubKeyHex) {
+            println("[Chess] Skipping own move (already applied locally)")
+            return
+        }
 
+        if (event.pubKey != gameState.opponentPubkey) {
+            println("[Chess] Move not from opponent (expected ${gameState.opponentPubkey.take(8)}, got ${event.pubKey.take(8)})")
+            return
+        }
+
+        println("[Chess] Applying opponent move: $san (move #$moveNumber)")
         gameState.applyOpponentMove(san, fen, moveNumber)
         updateBadgeCount()
     }
@@ -283,9 +338,10 @@ class DesktopChessViewModel(
     private fun handleGameEnded(event: LiveChessGameEndEvent) {
         val gameId = event.gameId() ?: return
 
-        // Store game in history before removing
+        // Store game in history before removing (skip if already in completed list)
+        val alreadyCompleted = _completedGames.value.any { it.gameId == gameId }
         val gameState = _activeGames.value[gameId]
-        if (gameState != null) {
+        if (gameState != null && !alreadyCompleted) {
             val completedGame =
                 CompletedGame(
                     gameId = gameId,
@@ -303,6 +359,7 @@ class DesktopChessViewModel(
         // Remove from active games
         if (_activeGames.value.containsKey(gameId)) {
             _activeGames.value = _activeGames.value - gameId
+            notifyActiveGamesChanged()
         }
 
         // Clean up challenge references
@@ -460,6 +517,7 @@ class DesktopChessViewModel(
                     )
 
                 _activeGames.value = _activeGames.value + (gameId to gameState)
+                notifyActiveGamesChanged()
                 gamesBeingCreated.remove(gameId)
                 _selectedGameId.value = gameId
                 _challenges.value = _challenges.value.filter { it.id != challengeEvent.id }
@@ -480,9 +538,18 @@ class DesktopChessViewModel(
             val challengerPubkey = acceptEvent.challengerPubkey() ?: return@launch
             val accepterPubkey = acceptEvent.pubKey
 
+            println("[Chess] startGameFromAcceptance: gameId=$gameId, isChallenger=$isChallenger")
+            println("[Chess] Pending moves in buffer: ${pendingMoves.keys}")
+
             // Skip if game already exists or is being created
-            if (_activeGames.value.containsKey(gameId)) return@launch
-            if (!gamesBeingCreated.add(gameId)) return@launch // Returns false if already present
+            if (_activeGames.value.containsKey(gameId)) {
+                println("[Chess] Game $gameId already exists, skipping")
+                return@launch
+            }
+            if (!gamesBeingCreated.add(gameId)) {
+                println("[Chess] Game $gameId already being created, skipping")
+                return@launch // Returns false if already present
+            }
 
             val opponentPubkey: String
             val playerColor: Color
@@ -514,11 +581,14 @@ class DesktopChessViewModel(
                     engine = engine,
                 )
 
+            println("[Chess] Adding game $gameId to active games, opponent=$opponentPubkey")
             _activeGames.value = _activeGames.value + (gameId to gameState)
+            notifyActiveGamesChanged()
             _challenges.value = _challenges.value.filter { it.gameId() != gameId }
             gamesBeingCreated.remove(gameId)
 
             // Apply any pending moves that arrived before the game was created
+            println("[Chess] About to apply pending moves for $gameId, buffer has: ${pendingMoves[gameId]?.size ?: 0} moves")
             applyPendingMoves(gameId, gameState)
         }
     }
@@ -527,13 +597,37 @@ class DesktopChessViewModel(
         gameId: String,
         gameState: LiveChessGameState,
     ) {
-        val moves = pendingMoves.remove(gameId) ?: return
+        val moves = pendingMoves.remove(gameId)
+        if (moves == null) {
+            println("[Chess] No pending moves for game $gameId")
+            return
+        }
 
-        // Sort by move number if available, then apply in order
+        println("[Chess] Processing ${moves.size} pending moves for game $gameId")
+
+        // Sort by move number to find the latest move
         val sortedMoves = moves.sortedBy { it.third ?: Int.MAX_VALUE }
 
-        for ((san, fen, moveNumber) in sortedMoves) {
-            gameState.applyOpponentMove(san, fen, moveNumber)
+        if (sortedMoves.isEmpty()) return
+
+        // Find the move with highest move number - its FEN has the current board state
+        val latestMove = sortedMoves.maxByOrNull { it.third ?: 0 }
+        if (latestMove != null) {
+            val (san, fen, moveNumber) = latestMove
+            println("[Chess] Syncing to latest position from move #$moveNumber: $san")
+            println("[Chess] FEN: $fen")
+
+            // Use forceResync to set the board to the correct position
+            gameState.forceResync(fen)
+
+            // Mark all received move numbers as processed to avoid duplicates
+            sortedMoves.forEach { (_, _, num) ->
+                if (num != null) {
+                    gameState.markMovesAsReceived(setOf(num))
+                }
+            }
+
+            println("[Chess] Board synced to position after ${sortedMoves.size} moves")
         }
 
         updateBadgeCount()
@@ -548,12 +642,36 @@ class DesktopChessViewModel(
         to: String,
     ) {
         val gameState = _activeGames.value[gameId] ?: return
-        val moveResult = gameState.makeMove(from, to)
+
+        // Parse promotion from 'to' if present (e.g., "e8q" -> square="e8", promotion=QUEEN)
+        val (targetSquare, promotion) = parsePromotionFromTarget(to)
+
+        val moveResult = gameState.makeMove(from, targetSquare, promotion)
         if (moveResult != null) {
             publishMoveEvent(gameId, moveResult)
         }
     }
 
+    /**
+     * Parse promotion piece from target square string.
+     * e.g., "e8q" -> ("e8", QUEEN), "e4" -> ("e4", null)
+     */
+    private fun parsePromotionFromTarget(to: String): Pair<String, PieceType?> {
+        if (to.length == 3) {
+            val square = to.substring(0, 2)
+            val promotion =
+                when (to[2].lowercaseChar()) {
+                    'q' -> PieceType.QUEEN
+                    'r' -> PieceType.ROOK
+                    'b' -> PieceType.BISHOP
+                    'n' -> PieceType.KNIGHT
+                    else -> null
+                }
+            return square to promotion
+        }
+        return to to null
+    }
+
     private fun publishMoveEvent(
         gameId: String,
         moveEvent: ChessMoveEvent,
@@ -606,20 +724,24 @@ class DesktopChessViewModel(
                 }
 
             if (success) {
-                // Store in history
-                val completedGame =
-                    CompletedGame(
-                        gameId = gameId,
-                        opponentPubkey = gameState.opponentPubkey,
-                        playerColor = gameState.playerColor,
-                        result = endData.result.notation,
-                        termination = endData.termination.name.lowercase(),
-                        winnerPubkey = endData.winnerPubkey,
-                        completedAt = TimeUtils.now(),
-                        moveCount = gameState.moveHistory.value.size,
-                    )
-                _completedGames.value = listOf(completedGame) + _completedGames.value
+                // Store in history (skip if already completed)
+                val alreadyCompleted = _completedGames.value.any { it.gameId == gameId }
+                if (!alreadyCompleted) {
+                    val completedGame =
+                        CompletedGame(
+                            gameId = gameId,
+                            opponentPubkey = gameState.opponentPubkey,
+                            playerColor = gameState.playerColor,
+                            result = endData.result.notation,
+                            termination = endData.termination.name.lowercase(),
+                            winnerPubkey = endData.winnerPubkey,
+                            completedAt = TimeUtils.now(),
+                            moveCount = gameState.moveHistory.value.size,
+                        )
+                    _completedGames.value = listOf(completedGame) + _completedGames.value
+                }
                 _activeGames.value = _activeGames.value - gameId
+                notifyActiveGamesChanged()
                 _error.value = null
             } else {
                 _error.value = "Failed to resign"
@@ -685,20 +807,24 @@ class DesktopChessViewModel(
                 }
 
             if (success) {
-                // Store in history and remove from active
-                val completedGame =
-                    CompletedGame(
-                        gameId = gameId,
-                        opponentPubkey = gameState.opponentPubkey,
-                        playerColor = gameState.playerColor,
-                        result = GameResult.DRAW.notation,
-                        termination = GameTermination.DRAW_AGREEMENT.name.lowercase(),
-                        winnerPubkey = null,
-                        completedAt = TimeUtils.now(),
-                        moveCount = gameState.moveHistory.value.size,
-                    )
-                _completedGames.value = listOf(completedGame) + _completedGames.value
+                // Store in history and remove from active (skip if already completed)
+                val alreadyCompleted = _completedGames.value.any { it.gameId == gameId }
+                if (!alreadyCompleted) {
+                    val completedGame =
+                        CompletedGame(
+                            gameId = gameId,
+                            opponentPubkey = gameState.opponentPubkey,
+                            playerColor = gameState.playerColor,
+                            result = GameResult.DRAW.notation,
+                            termination = GameTermination.DRAW_AGREEMENT.name.lowercase(),
+                            winnerPubkey = null,
+                            completedAt = TimeUtils.now(),
+                            moveCount = gameState.moveHistory.value.size,
+                        )
+                    _completedGames.value = listOf(completedGame) + _completedGames.value
+                }
                 _activeGames.value = _activeGames.value - gameId
+                notifyActiveGamesChanged()
                 _error.value = null
             } else {
                 _error.value = "Failed to accept draw"
@@ -754,6 +880,30 @@ class DesktopChessViewModel(
         _isLoading.value = false
     }
 
+    /**
+     * Refresh game states - polling callback.
+     * Triggers a subscription refresh to catch any missed events.
+     * The fixed filter (with opponent authors) will fetch opponent moves.
+     */
+    private suspend fun refreshGamesFromRelay(gameIds: Set<String>) {
+        if (gameIds.isEmpty()) return
+
+        // Trigger subscription controller refresh to re-fetch with current filters
+        // The filter now includes opponent pubkeys as authors, so it will catch their moves
+        subscriptionController?.forceRefresh()
+    }
+
+    /**
+     * Clean up expired challenges (older than 24 hours)
+     */
+    private fun cleanupExpiredChallenges() {
+        val now = TimeUtils.now()
+        _challenges.value =
+            _challenges.value.filter { challenge ->
+                (now - challenge.createdAt) < CHALLENGE_EXPIRY_SECONDS
+            }
+    }
+
     private fun updateBadgeCount() {
         val incomingChallenges = _challenges.value.count { it.opponentPubkey() == account.pubKeyHex }
         val yourTurnGames = _activeGames.value.values.count { it.isPlayerTurn() }
@@ -776,11 +926,7 @@ class DesktopChessViewModel(
         return false
     }
 
-    private fun generateGameId(): String {
-        val timestamp = TimeUtils.now()
-        val random = UUID.randomUUID().toString().take(8)
-        return "chess-$timestamp-$random"
-    }
+    private fun generateGameId(): String = ChessGameNameGenerator.generateGameId(TimeUtils.now())
 }
 
 /**

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/subscriptions/FilterBuilders.kt

@@ -95,6 +95,19 @@ object FilterBuilders {
             authors = pubKeyHexList,
         )
 
+    /**
+     * Creates a filter for user metadata (kind 0) from multiple authors.
+     * Alias for userMetadataBatch for API compatibility.
+     *
+     * @param pubKeys List of author public keys (hex-encoded, 64 chars each)
+     * @return Filter for user metadata
+     */
+    fun userMetadataMultiple(pubKeys: List<String>): Filter =
+        Filter(
+            kinds = listOf(0),
+            authors = pubKeys,
+        )
+
     /**
      * Creates a filter for contact list (kind 3) from a specific author.
      *

docs/chess-engine-refactoring.md

@@ -0,0 +1,287 @@
+# Chess Engine Refactoring
+
+## Context
+
+Chess feature had inconsistent state reconstruction:
+- **Android**: Replays moves from `LocalCache.addressables` (can get stale/desync)
+- **Desktop**: Buffers `pendingMoves` and syncs via `forceResync(fen)` (fragile)
+
+Both ViewModels (~1200 + ~956 lines) duplicate logic that now exists in shared components.
+
+## Completed Work
+
+### Shared Components (Done)
+
+| File | Location | Purpose |
+|------|----------|---------|
+| `ChessStateReconstructor` | `quartz/commonMain/` | Deterministic event→state reconstruction |
+| `ChessStateReconstructorTest` | `quartz/jvmAndroidTest/` | 22 integration tests |
+| `ChessEventCollector` | `commons/commonMain/` | Thread-safe event aggregation with dedup |
+| `ChessGameLoader` | `commons/commonMain/` | Converts ReconstructionResult → LiveChessGameState |
+| `ChessLobbyLogic` | `commons/commonMain/` | Shared business logic (challenges, moves, polling) |
+| `ChessLobbyState` | `commons/commonMain/` | Shared UI state (StateFlows for games, challenges, status) |
+| `ChessBroadcastStatus` | `commons/commonMain/` | Shared broadcast status sealed class |
+| `ChessPollingDelegate` | `commons/commonMain/` | Configurable periodic refresh |
+| `ChessFilterBuilder` | `commons/commonMain/subscription/` | Shared relay filter construction |
+| `ChessSubscriptionController` | `commons/commonMain/subscription/` | Platform subscription interface |
+| `ChessStatusBanner` | `amethyst/` (Android only) | Android broadcast status UI |
+
+### Test Coverage
+
+- Game lifecycle, move ordering/dedup, game end conditions
+- Viewer perspectives, draw offers, castling, determinism
+
+---
+
+## Target Architecture
+
+```
+BOTH PLATFORMS IDENTICAL:
+
+VM (~150 lines) → ChessLobbyLogic
+                      │
+                      ├─ publish: ChessEventPublisher (platform impl)
+                      │
+                      └─ refresh (periodic):
+                            one-shot REQ to relays
+                                    ↓
+                            transient ChessEventCollector (use-once)
+                                    ↓
+                            ChessStateReconstructor.reconstruct()
+                                    ↓
+                            LiveChessGameState → UI
+                            (collector discarded, no cache)
+```
+
+**Key principle**: No cache. Relays are the ONLY source of truth.
+
+Every refresh cycle:
+1. One-shot REQ to relays for all game events
+2. Transient collector → reconstruct → get state
+3. Diff against UI state, update if changed
+4. Discard collector
+
+Real-time subscription events apply moves **optimistically** to `LiveChessGameState`. Periodic full-reconstruction corrects any drift.
+
+---
+
+## Resolved Decisions
+
+### 1. No LocalCache for Chess
+
+**Decision**: Chess events must NOT enter LocalCache. Chess is inherently remote-only.
+
+**How to stop writes**: Remove chess event handlers from `LocalCache.justConsumeInnerInner()` (lines 2956-2960 in `LocalCache.kt`). These are:
+```kotlin
+is LiveChessGameChallengeEvent -> consume(event, relay, wasVerified)  // REMOVE
+is LiveChessGameAcceptEvent -> consume(event, relay, wasVerified)     // REMOVE
+is LiveChessMoveEvent -> consume(event, relay, wasVerified)           // REMOVE
+is LiveChessGameEndEvent -> consume(event, relay, wasVerified)        // REMOVE
+```
+
+Also remove chess DataSource from `RelaySubscriptionsCoordinator` (line 83: `val chess = ChessFilterAssembler(client)`). Chess manages its own relay subscriptions independently.
+
+### 2. One-Shot Relay Fetch (in commons)
+
+**Decision**: Create a shared one-shot fetch helper in commons using existing `IRequestListener` + `Channel` pattern.
+
+**Existing pattern** (proven in production):
+- `quartz/.../accessories/NostrClientSingleDownloadExt.kt` — single event download
+- `quartz/.../accessories/NostrClientSendAndWaitExt.kt` — multi-relay wait
+
+**Design**: The fetcher takes an `INostrClient` (available on both platforms) and uses the existing `IRequestListener` callback → `Channel` → `withTimeoutOrNull` pattern:
+
+```kotlin
+// commons/commonMain - shared one-shot fetch
+class ChessRelayFetchHelper(private val client: INostrClient) {
+
+    suspend fun fetchEvents(
+        filters: Map<NormalizedRelayUrl, List<Filter>>,
+        timeoutMs: Long = 30_000,
+    ): List<Event> {
+        val events = mutableListOf<Event>()
+        val eoseReceived = CompletableDeferred<Unit>()
+        val subId = UUID.randomUUID().toString().take(8)
+
+        val listener = object : IRequestListener {
+            override fun onEvent(event: Event, isLive: Boolean, relay: NormalizedRelayUrl, forFilters: List<Filter>?) {
+                events.add(event)
+            }
+            override fun onEose(relay: NormalizedRelayUrl, forFilters: List<Filter>?) {
+                eoseReceived.complete(Unit)
+            }
+        }
+
+        client.openReqSubscription(subId, filters, listener)
+        withTimeoutOrNull(timeoutMs) { eoseReceived.await() }
+        client.close(subId)
+
+        return events
+    }
+}
+```
+
+Platform adapters inject their `INostrClient`:
+- **Android**: `account.client` (or equivalent from relay pool)
+- **Desktop**: `relayManager.client`
+
+### 3. Metadata Provider (interface in commons)
+
+**Decision**: Shared `IUserMetadataProvider` interface in commons. Platform-specific implementations.
+
+Android uses `LocalCache.users[pubkey].info`, Desktop uses `UserMetadataCache`. Both implement:
+
+```kotlin
+// commons/commonMain
+interface IUserMetadataProvider {
+    fun getDisplayName(pubkey: String): String
+    fun getPictureUrl(pubkey: String): String?
+}
+```
+
+`ChessChallenge` gets enriched with display fields by calling provider at construction time.
+
+### 4. Challenge Type Migration
+
+**Decision**: Enrich `ChessChallenge` with display fields (displayName, avatarUrl) so it replaces both `Note` (Android) and `LiveChessGameChallengeEvent` (Desktop) in UI code.
+
+---
+
+## Implementation Steps
+
+### Step 1: Stop chess events entering LocalCache
+
+**Files:**
+- `amethyst/.../model/LocalCache.kt` — remove chess `when` branches (lines ~2956-2960)
+- `amethyst/.../service/relayClient/RelaySubscriptionsCoordinator.kt` — remove `val chess` DataSource
+
+### Step 2: Create one-shot relay fetch helper in commons
+
+**File:** `commons/src/commonMain/.../chess/ChessRelayFetchHelper.kt` (new)
+
+Uses `INostrClient` + `IRequestListener` + `Channel` pattern. Shared by both platforms.
+
+### Step 3: Create IUserMetadataProvider in commons
+
+**File:** `commons/src/commonMain/.../chess/IUserMetadataProvider.kt` (new)
+
+### Step 4: Rewrite ChessLobbyLogic (relay-first)
+
+**File:** `commons/src/commonMain/.../chess/ChessLobbyLogic.kt`
+
+Replace `ChessEventFetcher` with `ChessRelayFetcher` (wraps `ChessRelayFetchHelper`):
+
+```kotlin
+interface ChessRelayFetcher {
+    suspend fun fetchGameEvents(gameId: String): ChessGameEvents
+    suspend fun fetchChallenges(): List<LiveChessGameChallengeEvent>
+    suspend fun fetchRecentGames(): List<RelayGameSummary>
+}
+```
+
+Rewrite refresh cycle:
+```kotlin
+private suspend fun refreshGame(gameId: String) {
+    val events = relayFetcher.fetchGameEvents(gameId)  // one-shot from relays
+    val result = ChessStateReconstructor.reconstruct(events, userPubkey)
+    when (result) {
+        is ReconstructionResult.Success ->
+            state.replaceGameState(gameId, ChessGameLoader.toLiveGameState(result, userPubkey))
+        is ReconstructionResult.Error ->
+            state.setError("Game $gameId: ${result.message}")
+    }
+}
+```
+
+Add:
+- `handleIncomingEvent(event)` — optimistic real-time event routing
+- `handleGameAccepted()` + `startGameFromAcceptance()`
+- `acceptDraw()`, `declineDraw()`, `claimAbandonmentVictory()`
+- `retryWithBackoff()` for publish operations
+- Subscription controller integration
+
+### Step 5: Enhance ChessLobbyState
+
+**File:** `commons/src/commonMain/.../chess/ChessLobbyState.kt`
+
+Add:
+- `replaceGameState(gameId, newState)` — for full reconstruction updates
+- `completedGames: StateFlow<List<CompletedGame>>`
+- Enrich `ChessChallenge` with `displayName`, `avatarUrl`
+
+### Step 6: Platform adapters
+
+**Android:** `amethyst/.../chess/AndroidChessAdapter.kt` (new)
+- `AndroidChessPublisher` — wraps `account.signAndComputeBroadcast()`
+- `AndroidRelayFetcher` — wraps `ChessRelayFetchHelper(account.client)`
+- `AndroidMetadataProvider` — wraps `LocalCache.users[pubkey].info`
+
+**Desktop:** `desktopApp/.../chess/DesktopChessAdapter.kt` (new)
+- `DesktopChessPublisher` — wraps `account.signer.sign()` + `relayManager.broadcastToAll()`
+- `DesktopRelayFetcher` — wraps `ChessRelayFetchHelper(relayManager.client)`
+- `DesktopMetadataProvider` — wraps `UserMetadataCache`
+
+### Step 7: Rewrite Android ChessViewModel
+
+**File:** `amethyst/.../chess/ChessViewModel.kt` (1220 → ~150 lines)
+
+Thin wrapper: delegates to `ChessLobbyLogic`, exposes state, routes `LocalCache.live.newEventBundles` for real-time events.
+
+Delete: `RetryOperation`, `PublicGameInfo`, all LocalCache queries, all handle* methods, `ChessStatus`.
+
+### Step 8: Rewrite Desktop DesktopChessViewModel
+
+**File:** `desktopApp/.../chess/DesktopChessViewModel.kt` (956 → ~150 lines)
+
+Thin wrapper: delegates to `ChessLobbyLogic`, keeps `UserMetadataCache` platform-specific.
+
+Delete: `pendingMoves`, `pendingAccepts`, `challengesByGameId`, `processedEventIds`, `gamesBeingCreated`, all handle* methods, `applyPendingMoves`, `CompletedGame`.
+
+### Step 9: Create shared BroadcastBanner
+
+**File:** `commons/src/commonMain/.../chess/ChessBroadcastBanner.kt` (new)
+
+Extract from Android's `ChessStatusBanner.kt`, use `ChessBroadcastStatus` from commons.
+
+### Step 10: Update UI consumers
+
+**Android:**
+- `ChessGameScreen.kt` / `ChessLobbyScreen.kt`: `ChessChallenge` instead of `Note`
+- Remove `ChessStatusBanner.kt`, use shared `ChessBroadcastBanner`
+
+**Desktop:**
+- `ChessScreen.kt`: `ChessChallenge` instead of `LiveChessGameChallengeEvent`
+- Add `ChessBroadcastBanner`
+
+---
+
+## Files Modified
+
+| File | Action | Notes |
+|------|--------|-------|
+| `LocalCache.kt` | Edit | Remove chess event handlers |
+| `RelaySubscriptionsCoordinator.kt` | Edit | Remove chess DataSource |
+| `commons/.../ChessRelayFetchHelper.kt` | **New** | One-shot relay query helper |
+| `commons/.../IUserMetadataProvider.kt` | **New** | Metadata interface |
+| `commons/.../ChessLobbyLogic.kt` | Rewrite | Relay-first, event routing, reconstructor |
+| `commons/.../ChessLobbyState.kt` | Enhance | replaceGameState, completedGames, enriched ChessChallenge |
+| `commons/.../ChessBroadcastBanner.kt` | **New** | Shared broadcast status UI |
+| `amethyst/.../AndroidChessAdapter.kt` | **New** | Publisher + fetcher + metadata |
+| `amethyst/.../ChessViewModel.kt` | Rewrite | 1220→150 lines |
+| `amethyst/.../ChessStatusBanner.kt` | Delete | Replaced by shared |
+| `amethyst/.../ChessGameScreen.kt` | Update | Challenge type + banner |
+| `amethyst/.../ChessLobbyScreen.kt` | Update | Challenge type |
+| `desktopApp/.../DesktopChessAdapter.kt` | **New** | Publisher + fetcher + metadata |
+| `desktopApp/.../DesktopChessViewModel.kt` | Rewrite | 956→150 lines |
+| `desktopApp/.../ChessScreen.kt` | Update | Challenge type + banner |
+
+---
+
+## Verification
+
+1. `./gradlew :quartz:build`
+2. `./gradlew :commons:build`
+3. `./gradlew :amethyst:compileDebugKotlin`
+4. `./gradlew :desktopApp:compileKotlin`
+5. `./gradlew :quartz:jvmAndroidTest` — ChessStateReconstructor tests
+6. `./gradlew :desktopApp:run` — manual test: create challenge, play moves

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip64Chess/LiveChessGameEvents.kt

@@ -21,7 +21,7 @@
 package com.vitorpamplona.quartz.nip64Chess
 
 import androidx.compose.runtime.Immutable
-import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.core.BaseAddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
@@ -48,7 +48,7 @@ class LiveChessGameChallengeEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BaseAddressableEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
     companion object {
         const val KIND = 30064
 
@@ -100,7 +100,7 @@ class LiveChessGameAcceptEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BaseAddressableEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
     companion object {
         const val KIND = 30065
 
@@ -148,7 +148,7 @@ class LiveChessMoveEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BaseAddressableEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
     companion object {
         const val KIND = 30066
 
@@ -162,7 +162,8 @@ class LiveChessMoveEvent(
             createdAt: Long = TimeUtils.now(),
             initializer: TagArrayBuilder<LiveChessMoveEvent>.() -> Unit = {},
         ) = eventTemplate(KIND, comment, createdAt) {
-            add(arrayOf("d", gameId))
+            add(arrayOf("d", "$gameId-$moveNumber"))
+            add(arrayOf("game_id", gameId))
             add(arrayOf("move_number", moveNumber.toString()))
             add(arrayOf("san", san))
             add(arrayOf("fen", fen))
@@ -172,7 +173,7 @@ class LiveChessMoveEvent(
         }
     }
 
-    fun gameId(): String? = tags.firstOrNull { it.size >= 2 && it[0] == "d" }?.get(1)
+    fun gameId(): String? = tags.firstOrNull { it.size >= 2 && it[0] == "game_id" }?.get(1)
 
     fun moveNumber(): Int? =
         tags
@@ -211,7 +212,7 @@ class LiveChessGameEndEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BaseAddressableEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
     companion object {
         const val KIND = 30067
 
@@ -268,7 +269,7 @@ class LiveChessDrawOfferEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BaseAddressableEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
     companion object {
         const val KIND = 30068
 

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip64Chess/LiveChessGameState.kt

@@ -40,6 +40,8 @@ class LiveChessGameState(
     val playerColor: Color,
     val engine: ChessEngine,
     val createdAt: Long = TimeUtils.now(),
+    val isSpectator: Boolean = false,
+    val isPendingChallenge: Boolean = false,
 ) {
     companion object {
         // Abandon timeout: 24 hours without a move
@@ -92,8 +94,9 @@ class LiveChessGameState(
 
     /**
      * Check if it's the player's turn
+     * Spectators never have a turn
      */
-    fun isPlayerTurn(): Boolean = engine.getSideToMove() == playerColor
+    fun isPlayerTurn(): Boolean = !isSpectator && engine.getSideToMove() == playerColor
 
     /**
      * Make a move (called when player makes a move on the board)
@@ -129,9 +132,12 @@ class LiveChessGameState(
             checkGameEnd()
 
             // Return move event to publish
+            // Use ply count (half-move count) for moveNumber so each move gets a unique
+            // d-tag in the Nostr addressable event. The full-move counter from chesslib
+            // repeats for White/Black in the same move pair, causing d-tag collisions.
             return ChessMoveEvent(
                 gameId = gameId,
-                moveNumber = result.position.moveNumber,
+                moveNumber = _moveHistory.value.size,
                 san = result.san,
                 fen = engine.getFen(),
                 opponentPubkey = opponentPubkey,
@@ -403,6 +409,14 @@ class LiveChessGameState(
             """.trimIndent()
     }
 
+    /**
+     * Mark game as finished with the given result.
+     * Used when loading a game from cache that already has an end event.
+     */
+    fun markAsFinished(result: GameResult) {
+        _gameStatus.value = GameStatus.Finished(result)
+    }
+
     /**
      * Reset game to initial position
      */

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/utils/EventFactory.kt

@@ -113,6 +113,7 @@ import com.vitorpamplona.quartz.nip59Giftwrap.seals.SealedRumorEvent
 import com.vitorpamplona.quartz.nip59Giftwrap.wraps.GiftWrapEvent
 import com.vitorpamplona.quartz.nip62RequestToVanish.RequestToVanishEvent
 import com.vitorpamplona.quartz.nip64Chess.ChessGameEvent
+import com.vitorpamplona.quartz.nip64Chess.LiveChessDrawOfferEvent
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameAcceptEvent
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameChallengeEvent
 import com.vitorpamplona.quartz.nip64Chess.LiveChessGameEndEvent
@@ -193,6 +194,7 @@ class EventFactory {
                 LiveChessGameAcceptEvent.KIND -> LiveChessGameAcceptEvent(id, pubKey, createdAt, tags, content, sig)
                 LiveChessMoveEvent.KIND -> LiveChessMoveEvent(id, pubKey, createdAt, tags, content, sig)
                 LiveChessGameEndEvent.KIND -> LiveChessGameEndEvent(id, pubKey, createdAt, tags, content, sig)
+                LiveChessDrawOfferEvent.KIND -> LiveChessDrawOfferEvent(id, pubKey, createdAt, tags, content, sig)
                 ChannelCreateEvent.KIND -> ChannelCreateEvent(id, pubKey, createdAt, tags, content, sig)
                 ChannelHideMessageEvent.KIND -> ChannelHideMessageEvent(id, pubKey, createdAt, tags, content, sig)
                 ChannelListEvent.KIND -> ChannelListEvent(id, pubKey, createdAt, tags, content, sig)

quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip64Chess/ChessEngine.jvmAndroid.kt

@@ -27,32 +27,38 @@ import com.github.bhlangonijr.chesslib.Square
 import com.github.bhlangonijr.chesslib.move.Move
 
 /**
- * JVM/Android implementation of ChessEngine using kchesslib
+ * JVM/Android implementation of ChessEngine using kchesslib.
+ *
+ * Maintains its own SAN history because chesslib's Move.toString() returns
+ * UCI/coordinate notation (e.g. "e2e4") rather than proper SAN (e.g. "e4").
  */
 actual class ChessEngine {
     private val board = Board()
+    private val sanHistory = mutableListOf<String>()
 
     actual fun getFen(): String = board.fen
 
     actual fun loadFen(fen: String) {
         board.loadFromFen(fen)
+        sanHistory.clear()
     }
 
     actual fun reset() {
         board.loadFromFen("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1")
+        sanHistory.clear()
     }
 
     actual fun makeMove(san: String): MoveResult =
         try {
-            val move = board.doMove(san)
-            if (move != null) {
+            if (board.doMove(san)) {
+                // Input is already SAN from Nostr events, store directly
+                sanHistory.add(san)
                 MoveResult(
                     success = true,
                     san = san,
                     position = boardToPosition(),
                 )
             } else {
-                board.undoMove()
                 MoveResult(
                     success = false,
                     error = "Invalid move: $san",
@@ -86,8 +92,9 @@ actual class ChessEngine {
             val move = Move(fromSquare, toSquare, promotionPiece)
 
             if (board.legalMoves().contains(move)) {
+                val san = computeSan(move)
                 board.doMove(move)
-                val san = move.toString() // kchesslib converts to SAN
+                sanHistory.add(san)
                 MoveResult(
                     success = true,
                     san = san,
@@ -119,8 +126,7 @@ actual class ChessEngine {
 
     actual fun isLegalMove(san: String): Boolean =
         try {
-            val move = board.doMove(san)
-            if (move != null) {
+            if (board.doMove(san)) {
                 board.undoMove()
                 true
             } else {
@@ -162,6 +168,9 @@ actual class ChessEngine {
 
     actual fun undoMove() {
         board.undoMove()
+        if (sanHistory.isNotEmpty()) {
+            sanHistory.removeAt(sanHistory.lastIndex)
+        }
     }
 
     actual fun getPosition(): ChessPosition = boardToPosition()
@@ -172,11 +181,115 @@ actual class ChessEngine {
             Side.BLACK -> Color.BLACK
         }
 
-    actual fun getMoveHistory(): List<String> {
-        // kchesslib stores move history
-        return board.backup.mapNotNull { it?.move?.toString() }
+    actual fun getMoveHistory(): List<String> = sanHistory.toList()
+
+    /**
+     * Compute proper SAN notation for a move BEFORE it is applied to the board.
+     * Handles pieces, pawns, castling, captures, promotion, disambiguation, check/checkmate.
+     */
+    private fun computeSan(move: Move): String {
+        val fromSquare = move.from
+        val toSquare = move.to
+        val piece = board.getPiece(fromSquare)
+        val pt = piece.pieceType ?: return move.toString()
+        val promotionPiece = move.promotion ?: Piece.NONE
+
+        // Castling
+        if (pt == com.github.bhlangonijr.chesslib.PieceType.KING) {
+            val fileDiff = toSquare.file.ordinal - fromSquare.file.ordinal
+            if (fileDiff == 2) {
+                val suffix = checkSuffixAfterMove(move)
+                return "O-O$suffix"
+            }
+            if (fileDiff == -2) {
+                val suffix = checkSuffixAfterMove(move)
+                return "O-O-O$suffix"
+            }
+        }
+
+        val sb = StringBuilder()
+        val epTarget = board.enPassantTarget
+        val isCapture =
+            board.getPiece(toSquare) != Piece.NONE ||
+                (
+                    pt == com.github.bhlangonijr.chesslib.PieceType.PAWN &&
+                        epTarget != null && epTarget != Square.NONE && toSquare == epTarget
+                )
+
+        if (pt != com.github.bhlangonijr.chesslib.PieceType.PAWN) {
+            sb.append(sanSymbol(pt))
+
+            // Disambiguation: check if other pieces of same type can reach the same square
+            val ambiguous =
+                board.legalMoves().filterNotNull().filter {
+                    it.to == toSquare &&
+                        board.getPiece(it.from).pieceType == pt &&
+                        it.from != fromSquare
+                }
+
+            if (ambiguous.isNotEmpty()) {
+                val sameFile = ambiguous.any { it.from.file == fromSquare.file }
+                val sameRank = ambiguous.any { it.from.rank == fromSquare.rank }
+                when {
+                    !sameFile -> sb.append(fileChar(fromSquare))
+                    !sameRank -> sb.append(rankChar(fromSquare))
+                    else -> {
+                        sb.append(fileChar(fromSquare))
+                        sb.append(rankChar(fromSquare))
+                    }
+                }
+            }
+        } else if (isCapture) {
+            // Pawn captures include the source file
+            sb.append(fileChar(fromSquare))
+        }
+
+        if (isCapture) sb.append('x')
+
+        sb.append(toSquare.toString().lowercase())
+
+        // Promotion
+        if (promotionPiece != Piece.NONE) {
+            sb.append('=')
+            val promType = promotionPiece.pieceType
+            if (promType != null) sb.append(sanSymbol(promType))
+        }
+
+        // Check/checkmate suffix
+        sb.append(checkSuffixAfterMove(move))
+
+        return sb.toString()
     }
 
+    /**
+     * Temporarily apply a move to check for check/checkmate, then undo.
+     */
+    private fun checkSuffixAfterMove(move: Move): String {
+        board.doMove(move)
+        val suffix =
+            when {
+                board.isMated -> "#"
+                board.isKingAttacked -> "+"
+                else -> ""
+            }
+        board.undoMove()
+        return suffix
+    }
+
+    private fun sanSymbol(pt: com.github.bhlangonijr.chesslib.PieceType): String =
+        when (pt) {
+            com.github.bhlangonijr.chesslib.PieceType.KING -> "K"
+            com.github.bhlangonijr.chesslib.PieceType.QUEEN -> "Q"
+            com.github.bhlangonijr.chesslib.PieceType.ROOK -> "R"
+            com.github.bhlangonijr.chesslib.PieceType.BISHOP -> "B"
+            com.github.bhlangonijr.chesslib.PieceType.KNIGHT -> "N"
+            else -> ""
+        }
+
+    private fun fileChar(square: Square): Char = 'a' + square.file.ordinal
+
+    private fun rankChar(square: Square): Char = '1' + square.rank.ordinal
+
     /**
      * Convert kchesslib Board to our ChessPosition model
      */