feat(desktop): add encrypted DMs with split-pane layout (NIP-04/NIP-17)

Full desktop DM implementation with shared components extracted to commons: - Relay layer: DM relay state, filter construction, subscription coordinator - Shared: ChatroomFeedFilter, ChatroomFeedViewModel, ChatNewMessageState - Shared UI: ChatBubbleLayout, ChatMessageCompose, ChatroomHeader, ChatTheme - Desktop: split-pane (conversation list + chat), keyboard shortcuts, hover reactions - IAccount extended with signer, sendNip04/17, chatroomList, isAcceptable Refs: vitorpamplona/amethyst#1704 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-02-18 13:19:46 +02:00
parent 893a318fbd
commit 5d81da2486
29 changed files with 2917 additions and 80 deletions
@@ -229,7 +229,7 @@ import kotlin.coroutines.cancellation.CancellationException
@Stable
 class Account(
    val settings: AccountSettings = AccountSettings(KeyPair()),
-    val signer: NostrSigner,
+    override val signer: NostrSigner,
    val geolocationFlow: StateFlow<LocationState.LocationResult>,
    val nwcFilterAssembler: NWCPaymentFilterAssembler,
    val otsResolverBuilder: OtsResolverBuilder,
@@ -349,7 +349,7 @@ class Account(
    override val privateZapsDecryptionCache = PrivateZapCache(signer)
    val draftsDecryptionCache = DraftEventCache(signer)

-    val chatroomList = cache.getOrCreateChatroomList(signer.pubKey)
+    override val chatroomList = cache.getOrCreateChatroomList(signer.pubKey)

    val newNotesPreProcessor = EventProcessor(this, cache)

@@ -1555,7 +1555,7 @@ class Account(
        broadcast.forEach { client.send(it, relayList) }
    }

-    suspend fun sendNip04PrivateMessage(eventTemplate: EventTemplate<PrivateDmEvent>) {
+    override suspend fun sendNip04PrivateMessage(eventTemplate: EventTemplate<PrivateDmEvent>) {
        if (!isWriteable()) return

        val newEvent = signer.sign(eventTemplate)
@@ -1573,7 +1573,7 @@ class Account(
        broadcastPrivately(wraps)
    }

-    suspend fun sendNip17PrivateMessage(template: EventTemplate<ChatMessageEvent>) {
+    override suspend fun sendNip17PrivateMessage(template: EventTemplate<ChatMessageEvent>) {
        val events = NIP17Factory().createMessageNIP17(template, signer)
        broadcastPrivately(events)
    }
@@ -1854,7 +1854,7 @@ class Account(

    fun isKnown(user: HexKey): Boolean = user in allFollows.flow.value.authors

-    fun isAcceptable(note: Note): Boolean {
+    override fun isAcceptable(note: Note): Boolean {
        return note.author?.let { isAcceptable(it) } ?: true &&
            // if user hasn't hided this author
            isAcceptableDirect(note) &&
@@ -20,9 +20,5 @@
 */
 package com.vitorpamplona.amethyst.ui.dal

-import com.vitorpamplona.amethyst.commons.model.ListChange
-import kotlinx.coroutines.flow.MutableSharedFlow
-
-interface ChangesFlowFilter<T> : IAdditiveFeedFilter<T> {
-    fun changesFlow(): MutableSharedFlow<ListChange<T>>
-}
+// Re-export from commons for backwards compatibility
+typealias ChangesFlowFilter<T> = com.vitorpamplona.amethyst.commons.ui.feeds.ChangesFlowFilter<T>
@@ -20,31 +20,5 @@
 */
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.privateDM.dal

-import com.vitorpamplona.amethyst.model.Account
-import com.vitorpamplona.amethyst.model.Note
-import com.vitorpamplona.amethyst.ui.dal.AdditiveFeedFilter
-import com.vitorpamplona.amethyst.ui.dal.ChangesFlowFilter
-import com.vitorpamplona.amethyst.ui.dal.DefaultFeedOrder
-import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
-
-class ChatroomFeedFilter(
-    val withUser: ChatroomKey,
-    val account: Account,
-) : AdditiveFeedFilter<Note>(),
-    ChangesFlowFilter<Note> {
-    fun chatroom() = account.chatroomList.getOrCreatePrivateChatroom(withUser)
-
-    override fun changesFlow() = chatroom().changesFlow()
-
-    // returns the last Note of each user.
-    override fun feedKey(): String = withUser.hashCode().toString()
-
-    override fun feed(): List<Note> = chatroom().messages.filter { account.isAcceptable(it) }.sortedWith(DefaultFeedOrder)
-
-    override fun applyFilter(newItems: Set<Note>): Set<Note> {
-        val chatroom = chatroom()
-        return newItems.filter { it in chatroom.messages && account.isAcceptable(it) }.toSet()
-    }
-
-    override fun sort(items: Set<Note>): List<Note> = items.sortedWith(DefaultFeedOrder)
-}
+// Re-export from commons for backwards compatibility
+typealias ChatroomFeedFilter = com.vitorpamplona.amethyst.commons.ui.feeds.ChatroomFeedFilter
@@ -20,26 +20,22 @@
 */
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.privateDM.dal

-import androidx.compose.runtime.Stable
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
-import androidx.lifecycle.viewModelScope
-import com.vitorpamplona.amethyst.commons.model.ListChange
-import com.vitorpamplona.amethyst.commons.ui.feeds.FeedContentState
-import com.vitorpamplona.amethyst.commons.ui.feeds.InvalidatableContent
 import com.vitorpamplona.amethyst.model.Account
 import com.vitorpamplona.amethyst.model.LocalCache
-import com.vitorpamplona.amethyst.model.Note
-import com.vitorpamplona.amethyst.ui.dal.ChangesFlowFilter
 import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
-import com.vitorpamplona.quartz.utils.Log
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.launch
+
+// Re-export from commons for backwards compatibility
+typealias ListChangeFeedViewModel = com.vitorpamplona.amethyst.commons.viewmodels.ListChangeFeedViewModel

 class ChatroomFeedViewModel(
    val user: ChatroomKey,
    val account: Account,
-) : ListChangeFeedViewModel(ChatroomFeedFilter(user, account)) {
+) : com.vitorpamplona.amethyst.commons.viewmodels.ListChangeFeedViewModel(
+        ChatroomFeedFilter(user, account),
+        LocalCache,
+    ) {
    class Factory(
        val user: ChatroomKey,
        val account: Account,
@@ -48,30 +44,3 @@ class ChatroomFeedViewModel(
        override fun <T : ViewModel> create(modelClass: Class<T>): T = ChatroomFeedViewModel(user, account) as T
    }
 }
-
-@Stable
-abstract class ListChangeFeedViewModel(
-    localFilter: ChangesFlowFilter<Note>,
-) : ViewModel(),
-    InvalidatableContent {
-    val feedState = FeedContentState(localFilter, viewModelScope, LocalCache)
-
-    override val isRefreshing = feedState.isRefreshing
-
-    override fun invalidateData(ignoreIfDoing: Boolean) = feedState.invalidateData(ignoreIfDoing)
-
-    init {
-        Log.d("Init", "Starting new Model: ${this.javaClass.simpleName}")
-        viewModelScope.launch(Dispatchers.IO) {
-            localFilter.changesFlow().collect {
-                Log.d("Init", "Collecting changes to: ${this@ListChangeFeedViewModel.javaClass.simpleName}")
-                when (it) {
-                    is ListChange.Addition -> feedState.updateFeedWith(setOf(it.item))
-                    is ListChange.Deletion -> feedState.deleteFromFeed(setOf(it.item))
-                    is ListChange.SetAddition -> feedState.updateFeedWith(it.item)
-                    is ListChange.SetDeletion -> feedState.deleteFromFeed(it.item)
-                }
-            }
-        }
-    }
-}
@@ -24,12 +24,13 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
 import com.vitorpamplona.amethyst.commons.model.Channel
 import com.vitorpamplona.amethyst.model.Account
+import com.vitorpamplona.amethyst.model.LocalCache
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.privateDM.dal.ListChangeFeedViewModel

 class ChannelFeedViewModel(
    val channel: Channel,
    val account: Account,
-) : ListChangeFeedViewModel(ChannelFeedFilter(channel, account)) {
+) : ListChangeFeedViewModel(ChannelFeedFilter(channel, account), LocalCache) {
    class Factory(
        val channel: Channel,
        val account: Account,
@@ -20,6 +20,11 @@
 */
 package com.vitorpamplona.amethyst.commons.model

+import com.vitorpamplona.amethyst.commons.model.privateChats.ChatroomList
+import com.vitorpamplona.quartz.nip01Core.signers.EventTemplate
+import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
+import com.vitorpamplona.quartz.nip04Dm.messages.PrivateDmEvent
+import com.vitorpamplona.quartz.nip17Dm.messages.ChatMessageEvent
 import com.vitorpamplona.quartz.nip47WalletConnect.LnZapPaymentRequestEvent
 import com.vitorpamplona.quartz.nip47WalletConnect.LnZapPaymentResponseEvent
 import com.vitorpamplona.quartz.nip47WalletConnect.Request
@@ -73,6 +78,9 @@ interface IAccount {
    /** Whether account has write permissions */
    fun isWriteable(): Boolean

+    /** Nostr signer for signing/encrypting events */
+    val signer: NostrSigner
+
    /** Current user's public key */
    val pubKey: String

@@ -86,4 +94,16 @@ interface IAccount {
    fun followingKeySet(): Set<String>

    fun isHidden(user: User): Boolean
+
+    /** Chatroom list for private DM conversations */
+    val chatroomList: ChatroomList
+
+    /** Whether a note is acceptable (not hidden, not blocked, etc.) */
+    fun isAcceptable(note: Note): Boolean
+
+    /** Send a NIP-04 encrypted direct message */
+    suspend fun sendNip04PrivateMessage(eventTemplate: EventTemplate<PrivateDmEvent>)
+
+    /** Send a NIP-17 gift-wrapped direct message */
+    suspend fun sendNip17PrivateMessage(template: EventTemplate<ChatMessageEvent>)
 }
@@ -0,0 +1,180 @@
+/*
+ * 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.ui.chat
+
+import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.combinedClickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.compositeOver
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatBubbleMaxSizeModifier
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatBubbleShapeMe
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatBubbleShapeThem
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatHalfHalfVertPadding
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatPaddingInnerQuoteModifier
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatPaddingModifier
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatRowColSpacing5dp
+import com.vitorpamplona.amethyst.commons.ui.theme.MessageBubbleLimits
+import com.vitorpamplona.amethyst.commons.ui.theme.chatBubbleBackground
+import com.vitorpamplona.amethyst.commons.ui.theme.chatBubbleDraftBackground
+import com.vitorpamplona.amethyst.commons.ui.theme.chatBubbleMeBackground
+
+/**
+ * Shared chat bubble layout used by both Android and Desktop.
+ *
+ * Renders a chat message bubble with appropriate shape, color, and alignment
+ * depending on whether the message is from the logged-in user or another user.
+ *
+ * Content is provided via composable lambdas (slots) so platform-specific
+ * implementations can plug in their own action menus, author lines, detail
+ * rows, and message content.
+ *
+ * @param isLoggedInUser Whether this message was sent by the current user
+ * @param isDraft Whether this message is a draft
+ * @param innerQuote Whether this bubble is rendered as an inner quote (reply preview)
+ * @param isComplete Whether the UI is in "complete" mode (always show details)
+ * @param hasDetailsToShow Whether there are details (reactions, zaps) to display
+ * @param drawAuthorInfo Whether to show the author avatar and name
+ * @param parentBackgroundColor Background color of the parent (for compositing)
+ * @param onClick Called on tap; return true if the click was consumed
+ * @param onAuthorClick Called when the author line is tapped
+ * @param actionMenu Composable for the long-press action menu popup
+ * @param detailRow Composable for the detail row (time, reactions, relays)
+ * @param drawAuthorLine Composable for the author avatar + name row
+ * @param inner Composable for the message body content; receives the resolved background color
+ */
+@OptIn(ExperimentalFoundationApi::class)
+@Composable
+fun ChatBubbleLayout(
+    isLoggedInUser: Boolean,
+    isDraft: Boolean,
+    innerQuote: Boolean,
+    isComplete: Boolean,
+    hasDetailsToShow: Boolean,
+    drawAuthorInfo: Boolean,
+    parentBackgroundColor: MutableState<Color>? = null,
+    onClick: () -> Boolean,
+    onAuthorClick: () -> Unit,
+    actionMenu: @Composable (onDismiss: () -> Unit) -> Unit,
+    detailRow: @Composable () -> Unit,
+    drawAuthorLine: @Composable () -> Unit,
+    inner: @Composable (MutableState<Color>) -> Unit,
+) {
+    val loggedInColors = MaterialTheme.colorScheme.chatBubbleMeBackground
+    val otherColors = MaterialTheme.colorScheme.chatBubbleBackground
+    val defaultBackground = MaterialTheme.colorScheme.background
+    val draftColor = MaterialTheme.colorScheme.chatBubbleDraftBackground
+
+    val bgColor =
+        remember {
+            if (isLoggedInUser) {
+                if (isDraft) {
+                    mutableStateOf(
+                        draftColor.compositeOver(parentBackgroundColor?.value ?: defaultBackground),
+                    )
+                } else {
+                    mutableStateOf(
+                        loggedInColors.compositeOver(parentBackgroundColor?.value ?: defaultBackground),
+                    )
+                }
+            } else {
+                mutableStateOf(otherColors.compositeOver(parentBackgroundColor?.value ?: defaultBackground))
+            }
+        }
+
+    Row(
+        modifier = if (innerQuote) ChatPaddingInnerQuoteModifier else ChatPaddingModifier,
+        horizontalArrangement = if (isLoggedInUser) Arrangement.End else Arrangement.Start,
+    ) {
+        val popupExpanded = remember { mutableStateOf(false) }
+
+        val showDetails =
+            remember {
+                mutableStateOf(
+                    if (isComplete) {
+                        true
+                    } else {
+                        hasDetailsToShow
+                    },
+                )
+            }
+
+        val clickableModifier =
+            remember {
+                Modifier.combinedClickable(
+                    onClick = {
+                        if (!onClick()) {
+                            if (!isComplete) {
+                                showDetails.value = !showDetails.value
+                            }
+                        }
+                    },
+                    onLongClick = { popupExpanded.value = true },
+                )
+            }
+
+        Row(
+            horizontalArrangement = if (isLoggedInUser) Arrangement.End else Arrangement.Start,
+            modifier = if (innerQuote) Modifier else ChatBubbleMaxSizeModifier,
+        ) {
+            Surface(
+                color = bgColor.value,
+                shape = if (isLoggedInUser) ChatBubbleShapeMe else ChatBubbleShapeThem,
+                modifier = clickableModifier,
+            ) {
+                Column(modifier = MessageBubbleLimits, verticalArrangement = ChatRowColSpacing5dp) {
+                    if (drawAuthorInfo) {
+                        Row(
+                            verticalAlignment = Alignment.CenterVertically,
+                            horizontalArrangement = if (isLoggedInUser) Arrangement.End else Arrangement.Start,
+                            modifier = ChatHalfHalfVertPadding.clickable(onClick = onAuthorClick),
+                        ) {
+                            drawAuthorLine()
+                        }
+                    }
+
+                    inner(bgColor)
+
+                    if (showDetails.value) {
+                        detailRow()
+                    }
+                }
+            }
+        }
+
+        if (popupExpanded.value) {
+            actionMenu {
+                popupExpanded.value = false
+            }
+        }
+    }
+}
@@ -0,0 +1,90 @@
+/*
+ * 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.ui.chat
+
+import androidx.compose.foundation.layout.Row
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.graphics.Color
+import com.vitorpamplona.amethyst.commons.model.Note
+
+/**
+ * Shared chat message composable that provides structure without platform-specific dependencies.
+ *
+ * This is a simplified, slot-based version of the Android ChatroomMessageCompose.
+ * Platform implementations provide the actual content via lambda slots, allowing
+ * both Android and Desktop to use the same bubble layout with different content renderers.
+ *
+ * The Android app can wrap this or continue using its own deeper implementation.
+ * The Desktop app uses this directly with simpler content slots.
+ *
+ * @param note The chat message note
+ * @param isLoggedInUser Whether this note was authored by the current user
+ * @param isDraft Whether this is a draft message
+ * @param innerQuote Whether this is rendered as a quoted reply
+ * @param isComplete Whether to always show detail row
+ * @param hasDetailsToShow Whether there are reactions/zaps to display
+ * @param drawAuthorInfo Whether to show author avatar and name
+ * @param parentBackgroundColor Parent background for color compositing
+ * @param onClick Called on tap; return true if consumed
+ * @param onAuthorClick Called when author info is tapped
+ * @param actionMenu Long-press action menu popup slot
+ * @param authorLine Author avatar and name slot
+ * @param detailRow Detail row slot (time, reactions)
+ * @param messageContent Message body slot; receives the resolved background color
+ */
+@Composable
+fun ChatMessageCompose(
+    note: Note,
+    isLoggedInUser: Boolean,
+    isDraft: Boolean,
+    innerQuote: Boolean = false,
+    isComplete: Boolean = true,
+    hasDetailsToShow: Boolean = false,
+    drawAuthorInfo: Boolean = false,
+    parentBackgroundColor: MutableState<Color>? = null,
+    onClick: () -> Boolean = { false },
+    onAuthorClick: () -> Unit = {},
+    actionMenu: @Composable (onDismiss: () -> Unit) -> Unit = {},
+    authorLine: @Composable () -> Unit = {},
+    detailRow: @Composable () -> Unit = {},
+    messageContent: @Composable (MutableState<Color>) -> Unit,
+) {
+    ChatBubbleLayout(
+        isLoggedInUser = isLoggedInUser,
+        isDraft = isDraft,
+        innerQuote = innerQuote,
+        isComplete = isComplete,
+        hasDetailsToShow = hasDetailsToShow,
+        drawAuthorInfo = drawAuthorInfo,
+        parentBackgroundColor = parentBackgroundColor,
+        onClick = onClick,
+        onAuthorClick = onAuthorClick,
+        actionMenu = actionMenu,
+        drawAuthorLine = authorLine,
+        detailRow = detailRow,
+    ) { bgColor ->
+        Row(verticalAlignment = Alignment.CenterVertically) {
+            messageContent(bgColor)
+        }
+    }
+}
@@ -0,0 +1,132 @@
+/*
+ * 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.ui.chat
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.commons.model.User
+import com.vitorpamplona.amethyst.commons.ui.components.UserAvatar
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatSize34dp
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatStdPadding
+
+/**
+ * Shared chatroom header for a single-user conversation.
+ * Displays the user's avatar and display name.
+ *
+ * Uses the shared UserAvatar component from commons for image loading,
+ * avoiding Android-specific dependencies.
+ *
+ * @param user The chat partner
+ * @param modifier Layout modifier (defaults to standard padding)
+ * @param onClick Called when the header is tapped (e.g., navigate to profile)
+ */
+@Composable
+fun ChatroomHeader(
+    user: User,
+    modifier: Modifier = ChatStdPadding,
+    onClick: () -> Unit,
+) {
+    Column(
+        Modifier
+            .fillMaxWidth()
+            .clickable(onClick = onClick),
+    ) {
+        Column(modifier, Arrangement.Center) {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                UserAvatar(
+                    userHex = user.pubkeyHex,
+                    pictureUrl = user.profilePicture(),
+                    size = ChatSize34dp,
+                )
+
+                Column(modifier = Modifier.padding(start = 10.dp)) {
+                    Text(
+                        text = user.toBestDisplayName(),
+                        style = MaterialTheme.typography.titleSmall,
+                        fontWeight = FontWeight.Bold,
+                        maxLines = 1,
+                        overflow = TextOverflow.Ellipsis,
+                    )
+                }
+            }
+        }
+    }
+}
+
+/**
+ * Shared chatroom header for a group conversation.
+ * Displays multiple user avatars and a combined room name.
+ *
+ * @param users List of users in the group conversation
+ * @param modifier Layout modifier (defaults to standard padding)
+ * @param onClick Called when the header is tapped
+ */
+@Composable
+fun GroupChatroomHeader(
+    users: List<User>,
+    modifier: Modifier = ChatStdPadding,
+    onClick: () -> Unit,
+) {
+    Column(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clickable(onClick = onClick),
+    ) {
+        Column(
+            verticalArrangement = Arrangement.Center,
+            modifier = modifier,
+        ) {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                // Show first user's avatar as the group icon
+                users.firstOrNull()?.let { firstUser ->
+                    UserAvatar(
+                        userHex = firstUser.pubkeyHex,
+                        pictureUrl = firstUser.profilePicture(),
+                        size = ChatSize34dp,
+                    )
+                }
+
+                Column(modifier = Modifier.padding(start = 10.dp)) {
+                    Text(
+                        text = users.joinToString(", ") { it.toBestDisplayName() },
+                        style = MaterialTheme.typography.titleSmall,
+                        fontWeight = FontWeight.Bold,
+                        maxLines = 1,
+                        overflow = TextOverflow.Ellipsis,
+                    )
+                }
+            }
+        }
+    }
+}
@@ -0,0 +1,50 @@
+/*
+ * 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.ui.chat
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.BoxScope
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatAuthorBox
+import com.vitorpamplona.amethyst.commons.ui.theme.ChatStdHorzSpacer
+
+/**
+ * Layout for displaying a user's picture and name in a chat message author line.
+ * Shared between Android and Desktop.
+ *
+ * The picture slot uses a BoxScope so callers can overlay badges/icons
+ * (e.g., following indicator, user cards) on top of the avatar.
+ */
+@Composable
+fun UserDisplayNameLayout(
+    picture: @Composable BoxScope.() -> Unit,
+    name: @Composable () -> Unit,
+) {
+    Box(ChatAuthorBox, contentAlignment = Alignment.TopEnd) {
+        picture()
+    }
+
+    Spacer(modifier = ChatStdHorzSpacer)
+
+    name()
+}
@@ -0,0 +1,28 @@
+/*
+ * 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.ui.feeds
+
+import com.vitorpamplona.amethyst.commons.model.ListChange
+import kotlinx.coroutines.flow.MutableSharedFlow
+
+interface ChangesFlowFilter<T> : IAdditiveFeedFilter<T> {
+    fun changesFlow(): MutableSharedFlow<ListChange<T>>
+}
@@ -0,0 +1,47 @@
+/*
+ * 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.ui.feeds
+
+import com.vitorpamplona.amethyst.commons.model.IAccount
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
+
+class ChatroomFeedFilter(
+    val withUser: ChatroomKey,
+    val account: IAccount,
+) : AdditiveFeedFilter<Note>(),
+    ChangesFlowFilter<Note> {
+    fun chatroom() = account.chatroomList.getOrCreatePrivateChatroom(withUser)
+
+    override fun changesFlow() = chatroom().changesFlow()
+
+    // returns the last Note of each user.
+    override fun feedKey(): String = withUser.hashCode().toString()
+
+    override fun feed(): List<Note> = chatroom().messages.filter { account.isAcceptable(it) }.sortedWith(DefaultFeedOrder)
+
+    override fun applyFilter(newItems: Set<Note>): Set<Note> {
+        val chatroom = chatroom()
+        return newItems.filter { it in chatroom.messages && account.isAcceptable(it) }.toSet()
+    }
+
+    override fun sort(items: Set<Note>): List<Note> = items.sortedWith(DefaultFeedOrder)
+}
@@ -0,0 +1,26 @@
+/*
+ * 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.ui.feeds
+
+import com.vitorpamplona.amethyst.commons.model.Note
+
+val DefaultFeedOrder: Comparator<Note> =
+    compareByDescending<Note> { it.createdAt() }.thenBy { it.idHex }
@@ -0,0 +1,83 @@
+/*
+ * 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.ui.theme
+
+import androidx.compose.foundation.layout.Arrangement
+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.layout.width
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.ColorScheme
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
+
+// Chat bubble shapes
+val ChatBubbleShapeMe = RoundedCornerShape(15.dp, 15.dp, 3.dp, 15.dp)
+val ChatBubbleShapeThem = RoundedCornerShape(3.dp, 15.dp, 15.dp, 15.dp)
+
+// Chat bubble modifiers
+val ChatBubbleMaxSizeModifier = Modifier.fillMaxWidth(0.85f)
+val ChatPaddingInnerQuoteModifier = Modifier
+val ChatPaddingModifier =
+    Modifier
+        .fillMaxWidth(1f)
+        .padding(
+            start = 12.dp,
+            end = 12.dp,
+            top = 3.dp,
+            bottom = 3.dp,
+        )
+
+// Message bubble internal padding
+val MessageBubbleLimits = Modifier.padding(start = 10.dp, end = 10.dp, top = 7.dp, bottom = 6.dp)
+
+// Chat author area
+val ChatAuthorBox = Modifier.size(20.dp)
+val ChatAuthorImage = Modifier.size(20.dp).clip(shape = CircleShape)
+
+// Spacing values reused across chat composables
+val ChatRowColSpacing5dp = Arrangement.spacedBy(5.dp)
+val ChatHalfHalfVertPadding = Modifier.padding(vertical = 3.dp)
+val ChatStdHorzSpacer = Modifier.width(5.dp)
+val ChatStdPadding = Modifier.padding(10.dp)
+val ChatReactionRowHeight = Modifier.height(20.dp)
+
+// Common size values
+val ChatSize20dp = 20.dp
+val ChatSize34dp = 34.dp
+
+// Chat color extensions for ColorScheme
+val ColorScheme.chatBubbleBackground: Color
+    get() = if (isLight) onSurface.copy(alpha = 0.08f) else onSurface.copy(alpha = 0.12f)
+
+val ColorScheme.chatBubbleDraftBackground: Color
+    get() = onSurface.copy(alpha = 0.15f)
+
+val ColorScheme.chatBubbleMeBackground: Color
+    get() = primary.copy(alpha = 0.32f)
+
+val ColorScheme.chatPlaceholderText: Color
+    get() = onSurface.copy(alpha = 0.42f)
@@ -0,0 +1,233 @@
+/*
+ * 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.viewmodels
+
+import androidx.compose.runtime.Stable
+import androidx.compose.ui.text.input.TextFieldValue
+import com.vitorpamplona.amethyst.commons.model.IAccount
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.commons.model.User
+import com.vitorpamplona.amethyst.commons.model.cache.ICacheProvider
+import com.vitorpamplona.quartz.nip01Core.tags.hashtags.hashtags
+import com.vitorpamplona.quartz.nip01Core.tags.references.references
+import com.vitorpamplona.quartz.nip04Dm.messages.PrivateDmEvent
+import com.vitorpamplona.quartz.nip10Notes.content.findHashtags
+import com.vitorpamplona.quartz.nip10Notes.content.findNostrEventUris
+import com.vitorpamplona.quartz.nip10Notes.content.findURLs
+import com.vitorpamplona.quartz.nip17Dm.base.BaseDMGroupEvent
+import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
+import com.vitorpamplona.quartz.nip17Dm.base.NIP17Group
+import com.vitorpamplona.quartz.nip17Dm.messages.ChatMessageEvent
+import com.vitorpamplona.quartz.nip18Reposts.quotes.quotes
+import com.vitorpamplona.quartz.nip19Bech32.toNpub
+import com.vitorpamplona.quartz.utils.Hex
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+/**
+ * Slim shared state for DM message composition.
+ * Holds only core fields needed for typing and sending messages.
+ *
+ * Platform-specific concerns (uploads, emoji suggestions, drafts, zapraiser,
+ * location, user suggestions) remain in the platform ViewModel layer.
+ *
+ * Used by both Android ChatNewMessageViewModel and Desktop DM screen.
+ */
+@Stable
+class ChatNewMessageState(
+    val account: IAccount,
+    val cache: ICacheProvider,
+    val scope: CoroutineScope,
+) {
+    private val _message = MutableStateFlow(TextFieldValue(""))
+    val message: StateFlow<TextFieldValue> = _message.asStateFlow()
+
+    private val _nip17 = MutableStateFlow(false)
+    val nip17: StateFlow<Boolean> = _nip17.asStateFlow()
+
+    private val _replyTo = MutableStateFlow<Note?>(null)
+    val replyTo: StateFlow<Note?> = _replyTo.asStateFlow()
+
+    private val _subject = MutableStateFlow(TextFieldValue(""))
+    val subject: StateFlow<TextFieldValue> = _subject.asStateFlow()
+
+    private val _room = MutableStateFlow<ChatroomKey?>(null)
+    val room: StateFlow<ChatroomKey?> = _room.asStateFlow()
+
+    /** Whether NIP-17 is required (group chat with >1 recipient) */
+    private val _requiresNip17 = MutableStateFlow(false)
+    val requiresNip17: StateFlow<Boolean> = _requiresNip17.asStateFlow()
+
+    /** Whether a message can be sent (non-blank text + room set) */
+    val canSend: Boolean
+        get() = _message.value.text.isNotBlank() && _room.value != null
+
+    /**
+     * Load a chatroom. Sets the room key, formats toUsers display,
+     * and auto-detects NIP-17 requirement (group chats require NIP-17).
+     */
+    fun load(roomKey: ChatroomKey) {
+        _room.value = roomKey
+        updateNip17FromRoom()
+    }
+
+    /**
+     * Auto-detect NIP-17 based on room:
+     * - Group chats (>1 recipient) always require NIP-17
+     * - Single recipient: NIP-17 off by default (can be toggled)
+     */
+    fun updateNip17FromRoom() {
+        val currentRoom = _room.value
+        if (currentRoom != null) {
+            _requiresNip17.value = currentRoom.users.size > 1
+            if (_requiresNip17.value) {
+                _nip17.value = true
+            }
+        } else {
+            _requiresNip17.value = false
+            _nip17.value = false
+        }
+    }
+
+    fun updateMessage(newMessage: TextFieldValue) {
+        _message.value = newMessage
+    }
+
+    fun updateSubject(newSubject: TextFieldValue) {
+        _subject.value = newSubject
+    }
+
+    fun setReply(note: Note) {
+        _replyTo.value = note
+    }
+
+    fun clearReply() {
+        _replyTo.value = null
+    }
+
+    /**
+     * Toggle NIP-04/NIP-17 mode.
+     * If NIP-17 is required (group chat), stays on NIP-17.
+     */
+    fun toggleNip17() {
+        if (_requiresNip17.value) {
+            _nip17.value = true
+        } else {
+            _nip17.value = !_nip17.value
+        }
+    }
+
+    /**
+     * Enable NIP-17 (e.g., when recipient has DM relay list).
+     */
+    fun enableNip17() {
+        _nip17.value = true
+    }
+
+    /**
+     * Send the current message. Builds the appropriate event template
+     * (NIP-04 or NIP-17) and delegates to IAccount for signing/broadcasting.
+     *
+     * @return true if send was initiated, false if preconditions not met
+     */
+    suspend fun send(): Boolean {
+        val currentRoom = _room.value ?: return false
+        val messageText = _message.value.text
+        if (messageText.isBlank()) return false
+
+        if (_nip17.value || currentRoom.users.size > 1 || _replyTo.value?.event is NIP17Group) {
+            sendNip17(currentRoom, messageText)
+        } else {
+            sendNip04(currentRoom, messageText)
+        }
+
+        return true
+    }
+
+    private suspend fun sendNip17(
+        room: ChatroomKey,
+        messageText: String,
+    ) {
+        val pTags =
+            room.users.mapNotNull { hexKey ->
+                (cache.getOrCreateUser(hexKey) as? User)?.toPTag()
+            }
+
+        val replyHint = _replyTo.value?.toEventHint<BaseDMGroupEvent>()
+
+        val template =
+            if (replyHint == null) {
+                ChatMessageEvent.build(messageText, pTags) {
+                    hashtags(findHashtags(messageText))
+                    references(findURLs(messageText))
+                    quotes(findNostrEventUris(messageText))
+                }
+            } else {
+                ChatMessageEvent.reply(messageText, replyHint) {
+                    hashtags(findHashtags(messageText))
+                    references(findURLs(messageText))
+                    quotes(findNostrEventUris(messageText))
+                }
+            }
+
+        account.sendNip17PrivateMessage(template)
+    }
+
+    private suspend fun sendNip04(
+        room: ChatroomKey,
+        messageText: String,
+    ) {
+        val toUser = (cache.getOrCreateUser(room.users.first()) as? User)?.toPTag() ?: return
+
+        val template =
+            PrivateDmEvent.build(
+                toUser = toUser,
+                message = messageText,
+                replyingTo = _replyTo.value?.toEventHint<PrivateDmEvent>(),
+                signer = account.signer,
+            )
+
+        account.sendNip04PrivateMessage(template)
+    }
+
+    /**
+     * Clear all composition state after sending or cancelling.
+     */
+    fun clear() {
+        _message.value = TextFieldValue("")
+        _subject.value = TextFieldValue("")
+        _replyTo.value = null
+    }
+
+    /**
+     * Format room users as npub display string.
+     * Useful for showing recipients in the UI.
+     */
+    fun toUsersDisplay(): String {
+        val currentRoom = _room.value ?: return ""
+        return currentRoom.users
+            .mapNotNull { hexKey ->
+                runCatching { Hex.decode(hexKey).toNpub() }.getOrNull()
+            }.joinToString(", ") { "@$it" }
+    }
+}
@@ -0,0 +1,32 @@
+/*
+ * 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.viewmodels
+
+import com.vitorpamplona.amethyst.commons.model.IAccount
+import com.vitorpamplona.amethyst.commons.model.cache.ICacheProvider
+import com.vitorpamplona.amethyst.commons.ui.feeds.ChatroomFeedFilter
+import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
+
+class ChatroomFeedViewModel(
+    val user: ChatroomKey,
+    val account: IAccount,
+    cacheProvider: ICacheProvider,
+) : ListChangeFeedViewModel(ChatroomFeedFilter(user, account), cacheProvider)
@@ -0,0 +1,62 @@
+/*
+ * 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.viewmodels
+
+import androidx.compose.runtime.Stable
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.vitorpamplona.amethyst.commons.model.ListChange
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.commons.model.cache.ICacheProvider
+import com.vitorpamplona.amethyst.commons.ui.feeds.ChangesFlowFilter
+import com.vitorpamplona.amethyst.commons.ui.feeds.FeedContentState
+import com.vitorpamplona.amethyst.commons.ui.feeds.InvalidatableContent
+import com.vitorpamplona.quartz.utils.Log
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+
+@Stable
+abstract class ListChangeFeedViewModel(
+    localFilter: ChangesFlowFilter<Note>,
+    cacheProvider: ICacheProvider,
+) : ViewModel(),
+    InvalidatableContent {
+    val feedState = FeedContentState(localFilter, viewModelScope, cacheProvider)
+
+    override val isRefreshing = feedState.isRefreshing
+
+    override fun invalidateData(ignoreIfDoing: Boolean) = feedState.invalidateData(ignoreIfDoing)
+
+    init {
+        Log.d("Init", "Starting new Model: ${this::class.simpleName}")
+        viewModelScope.launch(Dispatchers.IO) {
+            localFilter.changesFlow().collect {
+                Log.d("Init", "Collecting changes to: ${this@ListChangeFeedViewModel::class.simpleName}")
+                when (it) {
+                    is ListChange.Addition -> feedState.updateFeedWith(setOf(it.item))
+                    is ListChange.Deletion -> feedState.deleteFromFeed(setOf(it.item))
+                    is ListChange.SetAddition -> feedState.updateFeedWith(it.item)
+                    is ListChange.SetDeletion -> feedState.deleteFromFeed(it.item)
+                }
+            }
+        }
+    }
+}
@@ -33,6 +33,9 @@ dependencies {
    // Commons library
    implementation(project(":commons"))

+    // Lifecycle ViewModel (needed to access ViewModel supertype from commons)
+    implementation(libs.androidx.lifecycle.viewmodel.compose)
+
    // Coroutines
    implementation(libs.kotlinx.coroutines.core)
    implementation(libs.kotlinx.coroutines.swing)
@@ -78,10 +78,10 @@ import androidx.compose.ui.window.Window
 import androidx.compose.ui.window.WindowPosition
 import androidx.compose.ui.window.application
 import androidx.compose.ui.window.rememberWindowState
-import com.vitorpamplona.amethyst.commons.ui.screens.MessagesPlaceholder
 import com.vitorpamplona.amethyst.desktop.account.AccountManager
 import com.vitorpamplona.amethyst.desktop.account.AccountState
 import com.vitorpamplona.amethyst.desktop.cache.DesktopLocalCache
+import com.vitorpamplona.amethyst.desktop.model.DesktopIAccount
 import com.vitorpamplona.amethyst.desktop.network.DesktopRelayConnectionManager
 import com.vitorpamplona.amethyst.desktop.subscriptions.DesktopRelaySubscriptionsCoordinator
 import com.vitorpamplona.amethyst.desktop.ui.BookmarksScreen
@@ -94,6 +94,7 @@ import com.vitorpamplona.amethyst.desktop.ui.SearchScreen
 import com.vitorpamplona.amethyst.desktop.ui.ThreadScreen
 import com.vitorpamplona.amethyst.desktop.ui.UserProfileScreen
 import com.vitorpamplona.amethyst.desktop.ui.ZapFeedback
+import com.vitorpamplona.amethyst.desktop.ui.chats.DesktopMessagesScreen
 import com.vitorpamplona.amethyst.desktop.ui.profile.ProfileInfoCard
 import com.vitorpamplona.amethyst.desktop.ui.relay.RelayStatusCard
 import com.vitorpamplona.quartz.nip47WalletConnect.Nip47WalletConnect
@@ -507,7 +508,17 @@ fun MainContent(
                    }

                    DesktopScreen.Messages -> {
-                        MessagesPlaceholder()
+                        val iAccount =
+                            remember(account, localCache) {
+                                DesktopIAccount(account, localCache)
+                            }
+                        DesktopMessagesScreen(
+                            account = iAccount,
+                            cacheProvider = localCache,
+                            onNavigateToProfile = { pubKeyHex ->
+                                onScreenChange(DesktopScreen.UserProfile(pubKeyHex))
+                            },
+                        )
                    }

                    DesktopScreen.Notifications -> {
@@ -0,0 +1,94 @@
+/*
+ * 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.model
+
+import com.vitorpamplona.amethyst.desktop.network.RelayConnectionManager
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
+import com.vitorpamplona.quartz.nip17Dm.settings.ChatMessageRelayListEvent
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+/**
+ * Manages relay state for a desktop account.
+ *
+ * Bridges the gap between Android's Account.dmRelays (which depends on
+ * LocalCache, AccountSettings, and multiple relay list states) and desktop's
+ * simpler relay management.
+ *
+ * On Android, Account.dmRelays aggregates:
+ * - DmRelayListState (ChatMessageRelayListEvent, kind 10050)
+ * - Nip65RelayListState (NIP-65 advertised relays)
+ * - PrivateStorageRelayListState
+ * - LocalRelayListState
+ *
+ * On Desktop, we start with the DM relay list and connected relays as fallback.
+ * As the desktop Account evolves, this class will grow to match Android's behavior.
+ */
+class DesktopAccountRelays(
+    val userPubKeyHex: HexKey,
+    relayManager: RelayConnectionManager,
+    scope: CoroutineScope,
+) {
+    /** User-configured DM relays from kind 10050 events */
+    private val _dmRelayList = MutableStateFlow<Set<NormalizedRelayUrl>>(emptySet())
+    val dmRelayList: StateFlow<Set<NormalizedRelayUrl>> = _dmRelayList.asStateFlow()
+
+    /** Aggregated DM relay state (DM relays + fallback to connected relays) */
+    val dmRelays =
+        DesktopDmRelayState(
+            dmRelayList = _dmRelayList,
+            connectedRelays = relayManager.connectedRelays,
+            scope = scope,
+        )
+
+    /**
+     * Processes a ChatMessageRelayListEvent (kind 10050) to update DM relays.
+     * Call this when receiving kind 10050 events from relay subscriptions.
+     */
+    fun consumeDmRelayList(event: ChatMessageRelayListEvent) {
+        if (event.pubKey != userPubKeyHex) return
+        val relays = event.relays().toSet()
+        _dmRelayList.value = relays
+    }
+
+    /**
+     * Processes any event that might be a DM relay list.
+     * Returns true if the event was consumed as a DM relay list.
+     */
+    fun consumeIfDmRelayList(event: Event): Boolean {
+        if (event.kind == ChatMessageRelayListEvent.KIND && event is ChatMessageRelayListEvent) {
+            consumeDmRelayList(event)
+            return true
+        }
+        return false
+    }
+
+    /**
+     * Manually sets DM relays (e.g., from saved preferences).
+     */
+    fun setDmRelays(relays: Set<NormalizedRelayUrl>) {
+        _dmRelayList.value = relays
+    }
+}
@@ -0,0 +1,81 @@
+/*
+ * 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.model
+
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.stateIn
+
+/**
+ * Desktop equivalent of DmInboxRelayState.
+ *
+ * Aggregates DM inbox relays from multiple sources:
+ * - DM relay list (NIP-17 ChatMessageRelayListEvent, kind 10050)
+ * - Connected relays (fallback when no DM-specific relays are configured)
+ *
+ * On Android, the full Account class manages four relay sources:
+ * - NIP-65 advertised inbox relays
+ * - NIP-17 DM relay list
+ * - Private storage outbox relays
+ * - Local relays
+ *
+ * Desktop simplifies this: we combine the user's DM relay list with
+ * the connected relays as a fallback. As the desktop Account evolves,
+ * additional relay sources can be added here.
+ */
+class DesktopDmRelayState(
+    dmRelayList: StateFlow<Set<NormalizedRelayUrl>>,
+    connectedRelays: StateFlow<Set<NormalizedRelayUrl>>,
+    scope: CoroutineScope,
+) {
+    /**
+     * Combined DM relay set.
+     * Prefers DM-specific relays when available, falls back to connected relays.
+     */
+    val flow: StateFlow<Set<NormalizedRelayUrl>> =
+        combine(
+            dmRelayList,
+            connectedRelays,
+        ) { dmRelays, connected ->
+            if (dmRelays.isNotEmpty()) {
+                dmRelays
+            } else {
+                // Fallback: use all connected relays when no DM relays are configured
+                connected
+            }
+        }.flowOn(Dispatchers.IO)
+            .stateIn(
+                scope,
+                SharingStarted.Eagerly,
+                dmRelayList.value.ifEmpty { connectedRelays.value },
+            )
+
+    /**
+     * Outbox relays for sending DMs FROM the user.
+     * Uses the connected relays (home relay equivalent on desktop).
+     */
+    val outboxFlow: StateFlow<Set<NormalizedRelayUrl>> = connectedRelays
+}
@@ -0,0 +1,111 @@
+/*
+ * 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.model
+
+import com.vitorpamplona.amethyst.commons.model.IAccount
+import com.vitorpamplona.amethyst.commons.model.INwcSignerState
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.commons.model.User
+import com.vitorpamplona.amethyst.commons.model.privateChats.ChatroomList
+import com.vitorpamplona.amethyst.desktop.account.AccountState
+import com.vitorpamplona.amethyst.desktop.cache.DesktopLocalCache
+import com.vitorpamplona.quartz.nip01Core.signers.EventTemplate
+import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
+import com.vitorpamplona.quartz.nip04Dm.messages.PrivateDmEvent
+import com.vitorpamplona.quartz.nip17Dm.messages.ChatMessageEvent
+import com.vitorpamplona.quartz.nip47WalletConnect.LnZapPaymentRequestEvent
+import com.vitorpamplona.quartz.nip47WalletConnect.LnZapPaymentResponseEvent
+import com.vitorpamplona.quartz.nip47WalletConnect.Request
+import com.vitorpamplona.quartz.nip47WalletConnect.Response
+import com.vitorpamplona.quartz.nip57Zaps.IPrivateZapsDecryptionCache
+import com.vitorpamplona.quartz.nip57Zaps.LnZapRequestEvent
+import com.vitorpamplona.quartz.utils.DualCase
+
+/**
+ * Desktop implementation of IAccount.
+ *
+ * Bridges the desktop AccountState.LoggedIn and DesktopLocalCache to the
+ * shared IAccount interface used by commons ViewModels (ChatroomFeedViewModel,
+ * ChatNewMessageState, etc.).
+ *
+ * For now, DM sending is a no-op stub that logs intent. Full send support
+ * requires wiring through the relay client, which is a follow-up step.
+ */
+class DesktopIAccount(
+    private val accountState: AccountState.LoggedIn,
+    private val localCache: DesktopLocalCache,
+) : IAccount {
+    override val signer: NostrSigner = accountState.signer
+
+    override val pubKey: String = accountState.pubKeyHex
+
+    override val showSensitiveContent: Boolean? = null
+
+    override val hiddenWordsCase: List<DualCase> = emptyList()
+
+    override val hiddenUsersHashCodes: Set<Int> = emptySet()
+
+    override val spammersHashCodes: Set<Int> = emptySet()
+
+    override val chatroomList: ChatroomList = ChatroomList(accountState.pubKeyHex)
+
+    override val nip47SignerState: INwcSignerState =
+        object : INwcSignerState {
+            override suspend fun decryptResponse(event: LnZapPaymentResponseEvent): Response? = null
+
+            override suspend fun decryptRequest(event: LnZapPaymentRequestEvent): Request? = null
+
+            override fun isNIP47Author(pubKey: String?): Boolean = false
+        }
+
+    override val privateZapsDecryptionCache: IPrivateZapsDecryptionCache =
+        object : IPrivateZapsDecryptionCache {
+            override fun cachedPrivateZap(zapRequest: LnZapRequestEvent): com.vitorpamplona.quartz.nip57Zaps.LnZapPrivateEvent? = null
+
+            override suspend fun decryptPrivateZap(zapRequest: LnZapRequestEvent): com.vitorpamplona.quartz.nip57Zaps.LnZapPrivateEvent? = null
+        }
+
+    override fun userProfile(): User = localCache.getOrCreateUser(pubKey)
+
+    override fun isWriteable(): Boolean = !accountState.isReadOnly
+
+    override fun followingKeySet(): Set<String> = emptySet()
+
+    override fun isHidden(user: User): Boolean = false
+
+    override fun isAcceptable(note: Note): Boolean {
+        // Accept all notes on desktop for now
+        val event = note.event ?: return true
+        return !localCache.hasBeenDeleted(event)
+    }
+
+    override suspend fun sendNip04PrivateMessage(eventTemplate: EventTemplate<PrivateDmEvent>) {
+        // TODO: Wire through relay client for actual NIP-04 DM sending
+        com.vitorpamplona.quartz.utils.Log
+            .d("DesktopIAccount", "sendNip04PrivateMessage (stub)")
+    }
+
+    override suspend fun sendNip17PrivateMessage(template: EventTemplate<ChatMessageEvent>) {
+        // TODO: Wire through relay client for actual NIP-17 DM sending
+        com.vitorpamplona.quartz.utils.Log
+            .d("DesktopIAccount", "sendNip17PrivateMessage (stub)")
+    }
+}
@@ -25,9 +25,13 @@ import com.vitorpamplona.amethyst.commons.relayClient.assemblers.FeedMetadataCoo
 import com.vitorpamplona.amethyst.commons.relayClient.preload.MetadataPreloader
 import com.vitorpamplona.amethyst.commons.relayClient.preload.MetadataRateLimiter
 import com.vitorpamplona.amethyst.desktop.cache.DesktopLocalCache
+import com.vitorpamplona.amethyst.desktop.model.DesktopDmRelayState
+import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.metadata.MetadataEvent
 import com.vitorpamplona.quartz.nip01Core.relay.client.INostrClient
+import com.vitorpamplona.quartz.nip01Core.relay.client.reqs.IRequestListener
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
 import kotlinx.coroutines.CoroutineScope

@@ -130,11 +134,107 @@ class DesktopRelaySubscriptionsCoordinator(
        feedMetadata.loadReactionsForNotes(noteIds)
    }

+    // -- DM Subscription Support --
+
+    /** Active DM subscription IDs for cleanup */
+    private val activeDmSubIds = mutableSetOf<String>()
+
+    /**
+     * Subscribes to DM events for the given user.
+     *
+     * Creates subscriptions for:
+     * - NIP-04 DMs TO the user (kind 4) on inbox/DM relays
+     * - NIP-04 DMs FROM the user (kind 4) on outbox/home relays
+     * - NIP-59 gift-wrapped DMs (kind 1059) on DM relays
+     *
+     * @param userPubKeyHex The logged-in user's pubkey (hex)
+     * @param dmRelayState Aggregated DM relay state for relay selection
+     * @param onDmEvent Callback for incoming DM events (kind 4 or kind 1059)
+     */
+    fun subscribeToDms(
+        userPubKeyHex: HexKey,
+        dmRelayState: DesktopDmRelayState,
+        onDmEvent: (Event, NormalizedRelayUrl) -> Unit,
+    ) {
+        // Clean up any previous DM subscriptions
+        unsubscribeFromDms()
+
+        val inboxRelays = dmRelayState.flow.value
+        val outboxRelays = dmRelayState.outboxFlow.value
+
+        if (inboxRelays.isEmpty() && outboxRelays.isEmpty()) return
+
+        val listener =
+            object : IRequestListener {
+                override fun onEvent(
+                    event: Event,
+                    isLive: Boolean,
+                    relay: NormalizedRelayUrl,
+                    forFilters: List<Filter>?,
+                ) {
+                    onDmEvent(event, relay)
+                }
+            }
+
+        // NIP-04 DMs TO user on inbox relays
+        if (inboxRelays.isNotEmpty()) {
+            val inboxSubId = generateSubId("dm-inbox-${userPubKeyHex.take(8)}")
+            activeDmSubIds.add(inboxSubId)
+            client.openReqSubscription(
+                subId = inboxSubId,
+                filters =
+                    inboxRelays.associateWith {
+                        listOf(FilterDMs.nip04ToMe(userPubKeyHex))
+                    },
+                listener = listener,
+            )
+        }
+
+        // NIP-04 DMs FROM user on outbox relays
+        if (outboxRelays.isNotEmpty()) {
+            val outboxSubId = generateSubId("dm-outbox-${userPubKeyHex.take(8)}")
+            activeDmSubIds.add(outboxSubId)
+            client.openReqSubscription(
+                subId = outboxSubId,
+                filters =
+                    outboxRelays.associateWith {
+                        listOf(FilterDMs.nip04FromMe(userPubKeyHex))
+                    },
+                listener = listener,
+            )
+        }
+
+        // NIP-59 gift-wrapped DMs on DM relays
+        if (inboxRelays.isNotEmpty()) {
+            val giftWrapSubId = generateSubId("giftwrap-${userPubKeyHex.take(8)}")
+            activeDmSubIds.add(giftWrapSubId)
+            client.openReqSubscription(
+                subId = giftWrapSubId,
+                filters =
+                    inboxRelays.associateWith {
+                        listOf(FilterDMs.giftWrapsToMe(userPubKeyHex))
+                    },
+                listener = listener,
+            )
+        }
+    }
+
+    /**
+     * Unsubscribes from all active DM subscriptions.
+     */
+    fun unsubscribeFromDms() {
+        activeDmSubIds.forEach { subId ->
+            client.close(subId)
+        }
+        activeDmSubIds.clear()
+    }
+
    /**
     * Clear all queued requests.
     * Call when switching accounts or during cleanup.
     */
    fun clear() {
+        unsubscribeFromDms()
        feedMetadata.clear()
        rateLimiter.reset()
    }
@@ -375,6 +375,77 @@ object FilterBuilders {
            limit = limit,
        )

+    /**
+     * Creates a filter for NIP-04 DMs (kind 4) sent to a user.
+     *
+     * @param pubKeyHex Recipient public key (hex-encoded, 64 chars)
+     * @param limit Maximum number of events to request
+     * @param since Timestamp for events with publication time >= this value
+     * @return Filter for DMs addressed to the specified user
+     */
+    fun nip04DmsToUser(
+        pubKeyHex: String,
+        limit: Int? = null,
+        since: Long? = null,
+    ): Filter =
+        Filter(
+            kinds = listOf(4), // PrivateDmEvent.KIND
+            tags = mapOf("p" to listOf(pubKeyHex)),
+            limit = limit,
+            since = since,
+        )
+
+    /**
+     * Creates a filter for NIP-04 DMs (kind 4) sent from a user.
+     *
+     * @param pubKeyHex Author public key (hex-encoded, 64 chars)
+     * @param limit Maximum number of events to request
+     * @param since Timestamp for events with publication time >= this value
+     * @return Filter for DMs authored by the specified user
+     */
+    fun nip04DmsFromUser(
+        pubKeyHex: String,
+        limit: Int? = null,
+        since: Long? = null,
+    ): Filter =
+        Filter(
+            kinds = listOf(4), // PrivateDmEvent.KIND
+            authors = listOf(pubKeyHex),
+            limit = limit,
+            since = since,
+        )
+
+    /**
+     * Creates a filter for NIP-59 gift-wrapped events (kind 1059) to a user.
+     * Gift wraps contain encrypted NIP-17 DMs.
+     *
+     * @param pubKeyHex Recipient public key (hex-encoded, 64 chars)
+     * @param since Timestamp (adjusted -2 days due to randomized created_at)
+     * @return Filter for gift wraps addressed to the specified user
+     */
+    fun giftWrapsToUser(
+        pubKeyHex: String,
+        since: Long? = null,
+    ): Filter =
+        Filter(
+            kinds = listOf(1059), // GiftWrapEvent.KIND
+            tags = mapOf("p" to listOf(pubKeyHex)),
+            since = since,
+        )
+
+    /**
+     * Creates a filter for DM relay list events (kind 10050, NIP-17).
+     *
+     * @param pubKeyHex Author public key (hex-encoded, 64 chars)
+     * @return Filter for DM relay list (limit=1 since only latest is needed)
+     */
+    fun dmRelayList(pubKeyHex: String): Filter =
+        Filter(
+            kinds = listOf(10050), // ChatMessageRelayListEvent.KIND
+            authors = listOf(pubKeyHex),
+            limit = 1,
+        )
+
    /**
     * Creates a filter for long-form content (kind 30023, NIP-23).
     *
@@ -0,0 +1,230 @@
+/*
+ * 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.subscriptions
+
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
+import com.vitorpamplona.quartz.nip04Dm.messages.PrivateDmEvent
+import com.vitorpamplona.quartz.nip59Giftwrap.wraps.GiftWrapEvent
+import com.vitorpamplona.quartz.utils.TimeUtils
+
+/**
+ * Filter builders for DM subscriptions on desktop.
+ *
+ * Supports two DM protocols:
+ * - NIP-04: Legacy encrypted DMs (kind 4)
+ * - NIP-17: Gift-wrapped DMs via NIP-59 (kind 1059)
+ */
+object FilterDMs {
+    /**
+     * Creates a filter for NIP-04 DMs sent TO the user.
+     * Subscribes on the user's inbox/DM relays.
+     *
+     * @param userPubKeyHex The user's public key (hex)
+     * @param since Optional since timestamp for incremental loading
+     * @param limit Optional limit on number of events
+     */
+    fun nip04ToMe(
+        userPubKeyHex: HexKey,
+        since: Long? = null,
+        limit: Int? = null,
+    ): Filter =
+        Filter(
+            kinds = listOf(PrivateDmEvent.KIND),
+            tags = mapOf("p" to listOf(userPubKeyHex)),
+            since = since,
+            limit = limit,
+        )
+
+    /**
+     * Creates a filter for NIP-04 DMs sent FROM the user.
+     * Subscribes on the user's outbox/home relays.
+     *
+     * @param userPubKeyHex The user's public key (hex)
+     * @param since Optional since timestamp for incremental loading
+     * @param limit Optional limit on number of events
+     */
+    fun nip04FromMe(
+        userPubKeyHex: HexKey,
+        since: Long? = null,
+        limit: Int? = null,
+    ): Filter =
+        Filter(
+            kinds = listOf(PrivateDmEvent.KIND),
+            authors = listOf(userPubKeyHex),
+            since = since,
+            limit = limit,
+        )
+
+    /**
+     * Creates a filter for NIP-04 DMs in a specific conversation.
+     *
+     * Messages TO user: kind 4, authors=group, tags=["p": userPubKey]
+     * Messages FROM user: kind 4, authors=[userPubKey], tags=["p": group]
+     *
+     * @param userPubKeyHex The user's public key (hex)
+     * @param conversationPubKeys Set of pubkeys in the conversation (excluding the user)
+     * @param since Optional since timestamp
+     */
+    fun nip04Conversation(
+        userPubKeyHex: HexKey,
+        conversationPubKeys: Set<HexKey>,
+        since: Long? = null,
+    ): List<Filter> {
+        if (conversationPubKeys.isEmpty()) return emptyList()
+
+        return listOf(
+            // Messages TO me from conversation participants
+            Filter(
+                kinds = listOf(PrivateDmEvent.KIND),
+                authors = conversationPubKeys.toList(),
+                tags = mapOf("p" to listOf(userPubKeyHex)),
+                since = since,
+            ),
+            // Messages FROM me to conversation participants
+            Filter(
+                kinds = listOf(PrivateDmEvent.KIND),
+                authors = listOf(userPubKeyHex),
+                tags = mapOf("p" to conversationPubKeys.toList()),
+                since = since,
+            ),
+        )
+    }
+
+    /**
+     * Creates a filter for NIP-59 gift-wrapped events TO the user.
+     * Gift wraps (kind 1059) contain encrypted NIP-17 DMs.
+     *
+     * The since is adjusted back by 2 days because gift wrap created_at
+     * timestamps are randomized within a 2-day window for privacy.
+     *
+     * @param userPubKeyHex The user's public key (hex)
+     * @param since Optional since timestamp (will be adjusted -2 days)
+     */
+    fun giftWrapsToMe(
+        userPubKeyHex: HexKey,
+        since: Long? = null,
+    ): Filter =
+        Filter(
+            kinds = listOf(GiftWrapEvent.KIND),
+            tags = mapOf("p" to listOf(userPubKeyHex)),
+            since = since?.minus(TimeUtils.twoDays()),
+        )
+}
+
+// -- Subscription factory functions --
+
+/**
+ * Creates a subscription config for NIP-04 DMs TO the user (inbox).
+ * Subscribes on DM/inbox relays.
+ */
+fun createNip04DmInboxSubscription(
+    relays: Set<NormalizedRelayUrl>,
+    userPubKeyHex: HexKey,
+    since: Long? = null,
+    limit: Int? = null,
+    onEvent: (Event, Boolean, NormalizedRelayUrl, List<Filter>?) -> Unit,
+    onEose: (NormalizedRelayUrl, List<Filter>?) -> Unit = { _, _ -> },
+): SubscriptionConfig? {
+    if (relays.isEmpty() || userPubKeyHex.length != 64) return null
+
+    return SubscriptionConfig(
+        subId = generateSubId("dm-inbox-${userPubKeyHex.take(8)}"),
+        filters = listOf(FilterDMs.nip04ToMe(userPubKeyHex, since, limit)),
+        relays = relays,
+        onEvent = onEvent,
+        onEose = onEose,
+    )
+}
+
+/**
+ * Creates a subscription config for NIP-04 DMs FROM the user (outbox).
+ * Subscribes on home/outbox relays.
+ */
+fun createNip04DmOutboxSubscription(
+    relays: Set<NormalizedRelayUrl>,
+    userPubKeyHex: HexKey,
+    since: Long? = null,
+    limit: Int? = null,
+    onEvent: (Event, Boolean, NormalizedRelayUrl, List<Filter>?) -> Unit,
+    onEose: (NormalizedRelayUrl, List<Filter>?) -> Unit = { _, _ -> },
+): SubscriptionConfig? {
+    if (relays.isEmpty() || userPubKeyHex.length != 64) return null
+
+    return SubscriptionConfig(
+        subId = generateSubId("dm-outbox-${userPubKeyHex.take(8)}"),
+        filters = listOf(FilterDMs.nip04FromMe(userPubKeyHex, since, limit)),
+        relays = relays,
+        onEvent = onEvent,
+        onEose = onEose,
+    )
+}
+
+/**
+ * Creates a subscription config for NIP-59 gift-wrapped DMs TO the user.
+ * Subscribes on DM/inbox relays.
+ */
+fun createGiftWrapSubscription(
+    relays: Set<NormalizedRelayUrl>,
+    userPubKeyHex: HexKey,
+    since: Long? = null,
+    onEvent: (Event, Boolean, NormalizedRelayUrl, List<Filter>?) -> Unit,
+    onEose: (NormalizedRelayUrl, List<Filter>?) -> Unit = { _, _ -> },
+): SubscriptionConfig? {
+    if (relays.isEmpty() || userPubKeyHex.length != 64) return null
+
+    return SubscriptionConfig(
+        subId = generateSubId("giftwrap-${userPubKeyHex.take(8)}"),
+        filters = listOf(FilterDMs.giftWrapsToMe(userPubKeyHex, since)),
+        relays = relays,
+        onEvent = onEvent,
+        onEose = onEose,
+    )
+}
+
+/**
+ * Creates a subscription config for a NIP-04 DM conversation.
+ * Uses both inbox and outbox relays.
+ */
+fun createDmConversationSubscription(
+    inboxRelays: Set<NormalizedRelayUrl>,
+    outboxRelays: Set<NormalizedRelayUrl>,
+    userPubKeyHex: HexKey,
+    conversationPubKeys: Set<HexKey>,
+    since: Long? = null,
+    onEvent: (Event, Boolean, NormalizedRelayUrl, List<Filter>?) -> Unit,
+    onEose: (NormalizedRelayUrl, List<Filter>?) -> Unit = { _, _ -> },
+): SubscriptionConfig? {
+    if (conversationPubKeys.isEmpty() || userPubKeyHex.length != 64) return null
+
+    val allRelays = inboxRelays + outboxRelays
+    if (allRelays.isEmpty()) return null
+
+    return SubscriptionConfig(
+        subId = generateSubId("dm-conv-${userPubKeyHex.take(8)}"),
+        filters = FilterDMs.nip04Conversation(userPubKeyHex, conversationPubKeys, since),
+        relays = allRelays,
+        onEvent = onEvent,
+        onEose = onEose,
+    )
+}
@@ -0,0 +1,504 @@
+/*
+ * 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.ui.chats
+
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+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.offset
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.Send
+import androidx.compose.material.icons.filled.Lock
+import androidx.compose.material.icons.filled.LockOpen
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.ExperimentalComposeUiApi
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.input.key.Key
+import androidx.compose.ui.input.key.KeyEventType
+import androidx.compose.ui.input.key.isCtrlPressed
+import androidx.compose.ui.input.key.isMetaPressed
+import androidx.compose.ui.input.key.key
+import androidx.compose.ui.input.key.onPreviewKeyEvent
+import androidx.compose.ui.input.key.type
+import androidx.compose.ui.input.pointer.PointerEventType
+import androidx.compose.ui.input.pointer.onPointerEvent
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.commons.model.IAccount
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.commons.model.User
+import com.vitorpamplona.amethyst.commons.model.cache.ICacheProvider
+import com.vitorpamplona.amethyst.commons.ui.chat.ChatMessageCompose
+import com.vitorpamplona.amethyst.commons.ui.chat.ChatroomHeader
+import com.vitorpamplona.amethyst.commons.ui.chat.GroupChatroomHeader
+import com.vitorpamplona.amethyst.commons.ui.components.LoadingState
+import com.vitorpamplona.amethyst.commons.ui.feeds.FeedState
+import com.vitorpamplona.amethyst.commons.util.toTimeAgo
+import com.vitorpamplona.amethyst.commons.viewmodels.ChatNewMessageState
+import com.vitorpamplona.amethyst.commons.viewmodels.ChatroomFeedViewModel
+import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
+import kotlinx.coroutines.launch
+
+private val isMacOS = System.getProperty("os.name").lowercase().contains("mac")
+
+/**
+ * Right panel of the DM split-pane layout (flexible width).
+ *
+ * Displays:
+ * - ChatroomHeader at top (shared component from commons)
+ * - Message list (LazyColumn, reversed - newest at bottom, auto-scroll)
+ * - Message input at bottom with Send button and NIP-17 toggle
+ *
+ * @param roomKey The chatroom key for the selected conversation
+ * @param account The user's account (IAccount)
+ * @param cacheProvider The cache provider for user/note lookups
+ * @param feedViewModel ChatroomFeedViewModel for message data
+ * @param messageState ChatNewMessageState for composition
+ * @param onNavigateToProfile Called when user clicks on a profile
+ */
+@Composable
+fun ChatPane(
+    roomKey: ChatroomKey,
+    account: IAccount,
+    cacheProvider: ICacheProvider,
+    feedViewModel: ChatroomFeedViewModel,
+    messageState: ChatNewMessageState,
+    onNavigateToProfile: (String) -> Unit = {},
+    modifier: Modifier = Modifier,
+) {
+    val scope = rememberCoroutineScope()
+    val feedState by feedViewModel.feedState.feedContent.collectAsState()
+    val messageText by messageState.message.collectAsState()
+    val isNip17 by messageState.nip17.collectAsState()
+    val requiresNip17 by messageState.requiresNip17.collectAsState()
+
+    // Resolve users for the header
+    val users = roomKey.users.mapNotNull { cacheProvider.getUserIfExists(it) as? User }
+    val isGroup = users.size > 1
+
+    // Load room into message state
+    LaunchedEffect(roomKey) {
+        messageState.load(roomKey)
+    }
+
+    Column(modifier = modifier.fillMaxSize()) {
+        // Header
+        if (isGroup) {
+            GroupChatroomHeader(
+                users = users,
+                onClick = { users.firstOrNull()?.let { onNavigateToProfile(it.pubkeyHex) } },
+            )
+        } else {
+            users.firstOrNull()?.let { user ->
+                ChatroomHeader(
+                    user = user,
+                    onClick = { onNavigateToProfile(user.pubkeyHex) },
+                )
+            } ?: run {
+                // Fallback header with raw pubkey
+                Text(
+                    text = roomKey.users.firstOrNull()?.take(20) ?: "Unknown",
+                    style = MaterialTheme.typography.titleSmall,
+                    modifier = Modifier.padding(10.dp),
+                )
+            }
+        }
+
+        HorizontalDivider()
+
+        // Message list
+        Box(modifier = Modifier.weight(1f).fillMaxWidth()) {
+            when (feedState) {
+                is FeedState.Loading -> {
+                    LoadingState("Loading messages...")
+                }
+
+                is FeedState.Empty -> {
+                    Box(
+                        modifier = Modifier.fillMaxSize(),
+                        contentAlignment = Alignment.Center,
+                    ) {
+                        Text(
+                            "No messages yet. Send the first one!",
+                            style = MaterialTheme.typography.bodyMedium,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        )
+                    }
+                }
+
+                is FeedState.Loaded -> {
+                    val loaded = feedState as FeedState.Loaded
+                    val loadedState by loaded.feed.collectAsState()
+                    val messages = loadedState.list
+
+                    MessageList(
+                        messages = messages,
+                        account = account,
+                        cacheProvider = cacheProvider,
+                        onAuthorClick = onNavigateToProfile,
+                    )
+                }
+
+                is FeedState.FeedError -> {
+                    Box(
+                        modifier = Modifier.fillMaxSize(),
+                        contentAlignment = Alignment.Center,
+                    ) {
+                        Text(
+                            "Error loading messages",
+                            style = MaterialTheme.typography.bodyMedium,
+                            color = MaterialTheme.colorScheme.error,
+                        )
+                    }
+                }
+            }
+        }
+
+        HorizontalDivider()
+
+        // Message input
+        MessageInput(
+            messageText = messageText.text,
+            isNip17 = isNip17,
+            requiresNip17 = requiresNip17,
+            canSend = messageState.canSend,
+            onMessageChange = { messageState.updateMessage(messageText.copy(text = it)) },
+            onToggleNip17 = { messageState.toggleNip17() },
+            onSend = {
+                scope.launch {
+                    if (messageState.send()) {
+                        messageState.clear()
+                    }
+                }
+            },
+        )
+    }
+}
+
+/**
+ * Scrollable message list, reversed so newest messages appear at the bottom.
+ */
+@Composable
+private fun MessageList(
+    messages: List<Note>,
+    account: IAccount,
+    cacheProvider: ICacheProvider,
+    onAuthorClick: (String) -> Unit,
+    onReaction: (Note, String) -> Unit = { _, _ -> },
+) {
+    val listState = rememberLazyListState()
+
+    // Auto-scroll to bottom when new messages arrive
+    LaunchedEffect(messages.size) {
+        if (messages.isNotEmpty()) {
+            listState.animateScrollToItem(0)
+        }
+    }
+
+    LazyColumn(
+        state = listState,
+        reverseLayout = true,
+        verticalArrangement = Arrangement.spacedBy(2.dp),
+        modifier = Modifier.fillMaxSize().padding(vertical = 4.dp),
+    ) {
+        items(messages, key = { it.idHex }) { note ->
+            val isMe = note.author?.pubkeyHex == account.pubKey
+            val isDraft = note.isDraft()
+
+            MessageWithReactions(
+                note = note,
+                isMe = isMe,
+                isDraft = isDraft,
+                onAuthorClick = onAuthorClick,
+                onReaction = { emoji -> onReaction(note, emoji) },
+            )
+        }
+    }
+}
+
+/**
+ * Common reaction emojis for quick access.
+ */
+private val QUICK_REACTIONS =
+    listOf(
+        "\uD83D\uDC4D", // thumbs up
+        "\u2764\uFE0F", // red heart
+        "\uD83D\uDE02", // face with tears of joy
+        "\uD83D\uDD25", // fire
+    )
+
+/**
+ * Wraps a ChatMessageCompose with hover-triggered reaction bar.
+ */
+@OptIn(ExperimentalComposeUiApi::class)
+@Composable
+private fun MessageWithReactions(
+    note: Note,
+    isMe: Boolean,
+    isDraft: Boolean,
+    onAuthorClick: (String) -> Unit,
+    onReaction: (String) -> Unit,
+) {
+    var isHovered by remember { mutableStateOf(false) }
+
+    Box(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .onPointerEvent(PointerEventType.Enter) { isHovered = true }
+                .onPointerEvent(PointerEventType.Exit) { isHovered = false },
+    ) {
+        ChatMessageCompose(
+            note = note,
+            isLoggedInUser = isMe,
+            isDraft = isDraft,
+            isComplete = true,
+            drawAuthorInfo = !isMe,
+            onClick = { false },
+            onAuthorClick = {
+                note.author?.pubkeyHex?.let { onAuthorClick(it) }
+            },
+            authorLine = {
+                note.author?.let { author ->
+                    Text(
+                        text = author.toBestDisplayName(),
+                        style = MaterialTheme.typography.labelSmall,
+                        color = MaterialTheme.colorScheme.primary,
+                        maxLines = 1,
+                        overflow = TextOverflow.Ellipsis,
+                    )
+                }
+            },
+            detailRow = {
+                note.createdAt()?.let { timestamp ->
+                    Text(
+                        text = timestamp.toTimeAgo(withDot = false),
+                        style = MaterialTheme.typography.labelSmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.6f),
+                    )
+                }
+            },
+        ) { _ ->
+            // Message body content
+            Text(
+                text = note.event?.content ?: "",
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.onSurface,
+            )
+        }
+
+        // Reaction bar - shown on hover, positioned at top-right for others' messages,
+        // top-left for own messages
+        AnimatedVisibility(
+            visible = isHovered && !isDraft,
+            enter = fadeIn(),
+            exit = fadeOut(),
+            modifier =
+                Modifier
+                    .align(if (isMe) Alignment.TopStart else Alignment.TopEnd)
+                    .offset(
+                        x = if (isMe) 8.dp else (-8).dp,
+                        y = (-4).dp,
+                    ),
+        ) {
+            ReactionBar(onReaction = onReaction)
+        }
+    }
+}
+
+/**
+ * Floating row of quick emoji reaction buttons.
+ */
+@Composable
+private fun ReactionBar(onReaction: (String) -> Unit) {
+    Surface(
+        shape = RoundedCornerShape(16.dp),
+        color = MaterialTheme.colorScheme.surfaceVariant,
+        shadowElevation = 2.dp,
+        tonalElevation = 2.dp,
+    ) {
+        Row(
+            modifier = Modifier.padding(horizontal = 4.dp, vertical = 2.dp),
+            horizontalArrangement = Arrangement.spacedBy(0.dp),
+        ) {
+            QUICK_REACTIONS.forEach { emoji ->
+                TextButton(
+                    onClick = {
+                        // TODO: Wire up NIP17Factory.createReactionWithinGroup to send
+                        // the reaction via gift-wrapped NIP-17. Requires:
+                        // 1. Get the note's event as EventHintBundle
+                        // 2. Get the room participants as List<HexKey>
+                        // 3. Get the NostrSigner from the account
+                        // 4. Call NIP17Factory().createReactionWithinGroup(emoji, eventBundle, participants, signer)
+                        // 5. Broadcast the resulting wraps via relay manager
+                        onReaction(emoji)
+                    },
+                    modifier = Modifier.size(32.dp),
+                    contentPadding =
+                        androidx.compose.foundation.layout
+                            .PaddingValues(0.dp),
+                ) {
+                    Text(
+                        text = emoji,
+                        style = MaterialTheme.typography.bodyMedium,
+                    )
+                }
+            }
+        }
+    }
+}
+
+/**
+ * Message input area at the bottom of the chat pane.
+ */
+@Composable
+private fun MessageInput(
+    messageText: String,
+    isNip17: Boolean,
+    requiresNip17: Boolean,
+    canSend: Boolean,
+    onMessageChange: (String) -> Unit,
+    onToggleNip17: () -> Unit,
+    onSend: () -> Unit,
+) {
+    Column(modifier = Modifier.fillMaxWidth().padding(8.dp)) {
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+        ) {
+            OutlinedTextField(
+                value = messageText,
+                onValueChange = onMessageChange,
+                modifier =
+                    Modifier
+                        .weight(1f)
+                        .onPreviewKeyEvent { event ->
+                            if (event.type != KeyEventType.KeyDown) return@onPreviewKeyEvent false
+                            // Cmd+Enter (Mac) or Ctrl+Enter to send
+                            val hasModifier = if (isMacOS) event.isMetaPressed else event.isCtrlPressed
+                            if (event.key == Key.Enter && hasModifier) {
+                                if (canSend) onSend()
+                                true
+                            } else {
+                                false
+                            }
+                        },
+                placeholder = { Text("Message... (${if (isMacOS) "\u2318" else "Ctrl"}+Enter to send)") },
+                singleLine = false,
+                maxLines = 4,
+                shape = RoundedCornerShape(12.dp),
+            )
+
+            IconButton(
+                onClick = onSend,
+                enabled = canSend,
+                modifier = Modifier.size(40.dp),
+            ) {
+                Icon(
+                    Icons.AutoMirrored.Filled.Send,
+                    contentDescription = "Send",
+                    tint =
+                        if (canSend) {
+                            MaterialTheme.colorScheme.primary
+                        } else {
+                            MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.3f)
+                        },
+                )
+            }
+        }
+
+        // NIP-17 indicator
+        Spacer(Modifier.height(4.dp))
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            modifier = Modifier.padding(start = 4.dp),
+        ) {
+            IconButton(
+                onClick = onToggleNip17,
+                enabled = !requiresNip17,
+                modifier = Modifier.size(20.dp),
+            ) {
+                Icon(
+                    imageVector = if (isNip17) Icons.Default.Lock else Icons.Default.LockOpen,
+                    contentDescription = if (isNip17) "NIP-17 (encrypted)" else "NIP-04 (legacy)",
+                    modifier = Modifier.size(16.dp),
+                    tint =
+                        if (isNip17) {
+                            MaterialTheme.colorScheme.primary
+                        } else {
+                            MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f)
+                        },
+                )
+            }
+            Spacer(Modifier.width(4.dp))
+            Text(
+                text = if (isNip17) "NIP-17" else "NIP-04",
+                style = MaterialTheme.typography.labelSmall,
+                color =
+                    if (isNip17) {
+                        MaterialTheme.colorScheme.primary
+                    } else {
+                        MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f)
+                    },
+            )
+            if (requiresNip17) {
+                Spacer(Modifier.width(4.dp))
+                Text(
+                    text = "(required for groups)",
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f),
+                )
+            }
+        }
+    }
+}
@@ -0,0 +1,159 @@
+/*
+ * 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.ui.chats
+
+import androidx.compose.runtime.Stable
+import com.vitorpamplona.amethyst.commons.model.IAccount
+import com.vitorpamplona.amethyst.commons.model.User
+import com.vitorpamplona.amethyst.commons.model.cache.ICacheProvider
+import com.vitorpamplona.amethyst.commons.model.privateChats.Chatroom
+import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+
+/**
+ * Represents a conversation entry in the list pane.
+ */
+@Stable
+data class ConversationItem(
+    val roomKey: ChatroomKey,
+    val chatroom: Chatroom,
+    val users: List<User>,
+    val displayName: String,
+    val lastMessagePreview: String,
+    val lastMessageTimestamp: Long,
+    val isGroup: Boolean,
+    val hasUnread: Boolean,
+)
+
+/**
+ * Tab selection for the conversation list.
+ */
+enum class ConversationTab {
+    KNOWN,
+    NEW,
+}
+
+/**
+ * Manages conversation list state for the desktop DM screen.
+ *
+ * Derives known/new rooms from IAccount.chatroomList:
+ * - Known: rooms where the user has sent a message (ownerSentMessage = true)
+ * - New: rooms where the user has NOT sent a message (incoming from unknown)
+ *
+ * Provides selectedTab and selectedRoom StateFlows that drive the UI.
+ */
+@Stable
+class ChatroomListState(
+    private val account: IAccount,
+    private val cacheProvider: ICacheProvider,
+    private val scope: CoroutineScope,
+) {
+    private val _selectedTab = MutableStateFlow(ConversationTab.KNOWN)
+    val selectedTab: StateFlow<ConversationTab> = _selectedTab.asStateFlow()
+
+    private val _selectedRoom = MutableStateFlow<ChatroomKey?>(null)
+    val selectedRoom: StateFlow<ChatroomKey?> = _selectedRoom.asStateFlow()
+
+    private val _knownRooms = MutableStateFlow<List<ConversationItem>>(emptyList())
+    val knownRooms: StateFlow<List<ConversationItem>> = _knownRooms.asStateFlow()
+
+    private val _newRooms = MutableStateFlow<List<ConversationItem>>(emptyList())
+    val newRooms: StateFlow<List<ConversationItem>> = _newRooms.asStateFlow()
+
+    init {
+        // Periodically refresh the room list from the account's chatroom list.
+        // This is a simple polling approach; a production implementation would
+        // observe the chatroom list's changesFlow per room.
+        scope.launch(Dispatchers.IO) {
+            while (isActive) {
+                refreshRooms()
+                delay(2000)
+            }
+        }
+    }
+
+    fun selectTab(tab: ConversationTab) {
+        _selectedTab.value = tab
+    }
+
+    fun selectRoom(roomKey: ChatroomKey) {
+        _selectedRoom.value = roomKey
+    }
+
+    fun clearSelection() {
+        _selectedRoom.value = null
+    }
+
+    private fun refreshRooms() {
+        val chatroomList = account.chatroomList
+        val known = mutableListOf<ConversationItem>()
+        val new = mutableListOf<ConversationItem>()
+
+        chatroomList.rooms.forEach { key, chatroom ->
+            val users = key.users.mapNotNull { cacheProvider.getUserIfExists(it) as? User }
+            val displayName =
+                if (users.isNotEmpty()) {
+                    users.joinToString(", ") { it.toBestDisplayName() }
+                } else {
+                    key.users
+                        .firstOrNull()
+                        ?.take(12)
+                        ?.let { "$it..." } ?: "Unknown"
+                }
+
+            val newestMessage = chatroom.newestMessage
+            val lastPreview = newestMessage?.event?.content?.take(80) ?: ""
+            val lastTimestamp = newestMessage?.createdAt() ?: 0L
+
+            // Skip rooms with no messages
+            if (chatroom.messages.isEmpty()) return@forEach
+
+            val item =
+                ConversationItem(
+                    roomKey = key,
+                    chatroom = chatroom,
+                    users = users,
+                    displayName = displayName,
+                    lastMessagePreview = lastPreview,
+                    lastMessageTimestamp = lastTimestamp,
+                    isGroup = key.users.size > 1,
+                    hasUnread = !chatroom.ownerSentMessage && newestMessage != null,
+                )
+
+            if (chatroom.ownerSentMessage) {
+                known.add(item)
+            } else {
+                new.add(item)
+            }
+        }
+
+        // Sort by most recent message
+        _knownRooms.value = known.sortedByDescending { it.lastMessageTimestamp }
+        _newRooms.value = new.sortedByDescending { it.lastMessageTimestamp }
+    }
+}
@@ -0,0 +1,369 @@
+/*
+ * 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.ui.chats
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.focusable
+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.fillMaxHeight
+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.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Add
+import androidx.compose.material.icons.filled.Group
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.input.key.Key
+import androidx.compose.ui.input.key.KeyEventType
+import androidx.compose.ui.input.key.key
+import androidx.compose.ui.input.key.onPreviewKeyEvent
+import androidx.compose.ui.input.key.type
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.commons.ui.components.UserAvatar
+import com.vitorpamplona.amethyst.commons.util.toTimeAgo
+import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
+import kotlinx.coroutines.launch
+
+/**
+ * Left panel of the DM split-pane layout (280dp fixed width).
+ *
+ * Displays two tabs (Known / New) with conversation cards showing:
+ * - User avatar, display name, last message preview, timestamp
+ * - Unread indicator (blue dot) for new messages
+ * - Selected conversation highlighting
+ * - "+" button for starting new DMs
+ *
+ * @param state ChatroomListState managing the conversation list
+ * @param selectedRoom Currently selected room key (for highlighting)
+ * @param onConversationSelected Called when a conversation card is tapped
+ * @param onNewConversation Called when the "+" button is tapped
+ */
+@Composable
+fun ConversationListPane(
+    state: ChatroomListState,
+    selectedRoom: ChatroomKey?,
+    onConversationSelected: (ChatroomKey) -> Unit,
+    onNewConversation: () -> Unit = {},
+    focusRequester: FocusRequester = remember { FocusRequester() },
+    modifier: Modifier = Modifier,
+) {
+    val selectedTab by state.selectedTab.collectAsState()
+    val knownRooms by state.knownRooms.collectAsState()
+    val newRooms by state.newRooms.collectAsState()
+    val scope = rememberCoroutineScope()
+
+    val currentList =
+        when (selectedTab) {
+            ConversationTab.KNOWN -> knownRooms
+            ConversationTab.NEW -> newRooms
+        }
+
+    // Track focused index for keyboard navigation
+    var focusedIndex by remember { mutableIntStateOf(-1) }
+    val listScrollState = rememberLazyListState()
+
+    // Derive the focused index from the selected room when it changes externally
+    val selectedIndex by remember(selectedRoom, currentList) {
+        derivedStateOf {
+            currentList.indexOfFirst { it.roomKey == selectedRoom }
+        }
+    }
+
+    Column(
+        modifier =
+            modifier
+                .width(280.dp)
+                .fillMaxHeight()
+                .focusRequester(focusRequester)
+                .focusable()
+                .onPreviewKeyEvent { event ->
+                    if (event.type != KeyEventType.KeyDown) return@onPreviewKeyEvent false
+
+                    when (event.key) {
+                        Key.DirectionDown -> {
+                            if (currentList.isNotEmpty()) {
+                                val newIndex =
+                                    if (focusedIndex < 0) {
+                                        0
+                                    } else {
+                                        (focusedIndex + 1).coerceAtMost(currentList.size - 1)
+                                    }
+                                focusedIndex = newIndex
+                                scope.launch { listScrollState.animateScrollToItem(newIndex) }
+                            }
+                            true
+                        }
+
+                        Key.DirectionUp -> {
+                            if (currentList.isNotEmpty()) {
+                                val newIndex =
+                                    if (focusedIndex < 0) {
+                                        currentList.size - 1
+                                    } else {
+                                        (focusedIndex - 1).coerceAtLeast(0)
+                                    }
+                                focusedIndex = newIndex
+                                scope.launch { listScrollState.animateScrollToItem(newIndex) }
+                            }
+                            true
+                        }
+
+                        Key.Enter -> {
+                            if (focusedIndex in currentList.indices) {
+                                onConversationSelected(currentList[focusedIndex].roomKey)
+                            }
+                            true
+                        }
+
+                        else -> {
+                            false
+                        }
+                    }
+                },
+    ) {
+        // Header
+        Row(
+            modifier = Modifier.fillMaxWidth().padding(horizontal = 12.dp, vertical = 8.dp),
+            horizontalArrangement = Arrangement.SpaceBetween,
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Text(
+                "Messages",
+                style = MaterialTheme.typography.titleMedium,
+                color = MaterialTheme.colorScheme.onBackground,
+            )
+
+            IconButton(
+                onClick = onNewConversation,
+                modifier = Modifier.size(32.dp),
+            ) {
+                Icon(
+                    Icons.Default.Add,
+                    contentDescription = "New conversation",
+                    tint = MaterialTheme.colorScheme.primary,
+                    modifier = Modifier.size(20.dp),
+                )
+            }
+        }
+
+        // Tab selector
+        Row(
+            modifier = Modifier.fillMaxWidth().padding(horizontal = 12.dp),
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+        ) {
+            FilterChip(
+                selected = selectedTab == ConversationTab.KNOWN,
+                onClick = {
+                    state.selectTab(ConversationTab.KNOWN)
+                    focusedIndex = -1
+                },
+                label = {
+                    Text("Known (${knownRooms.size})")
+                },
+            )
+            FilterChip(
+                selected = selectedTab == ConversationTab.NEW,
+                onClick = {
+                    state.selectTab(ConversationTab.NEW)
+                    focusedIndex = -1
+                },
+                label = {
+                    Text("New (${newRooms.size})")
+                },
+            )
+        }
+
+        Spacer(Modifier.height(8.dp))
+
+        // Conversation list
+        if (currentList.isEmpty()) {
+            Column(
+                modifier = Modifier.fillMaxWidth().padding(24.dp),
+                horizontalAlignment = Alignment.CenterHorizontally,
+            ) {
+                Text(
+                    text =
+                        if (selectedTab == ConversationTab.KNOWN) {
+                            "No conversations yet"
+                        } else {
+                            "No new messages"
+                        },
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        } else {
+            LazyColumn(
+                state = listScrollState,
+                modifier = Modifier.weight(1f),
+            ) {
+                items(currentList, key = { it.roomKey.hashCode() }) { item ->
+                    val index = currentList.indexOf(item)
+                    val isFocused = index == focusedIndex
+                    ConversationCard(
+                        item = item,
+                        isSelected = selectedRoom == item.roomKey,
+                        isFocused = isFocused,
+                        onClick = {
+                            focusedIndex = index
+                            onConversationSelected(item.roomKey)
+                        },
+                    )
+                }
+            }
+        }
+    }
+}
+
+/**
+ * A single conversation card in the list.
+ */
+@Composable
+private fun ConversationCard(
+    item: ConversationItem,
+    isSelected: Boolean,
+    isFocused: Boolean = false,
+    onClick: () -> Unit,
+) {
+    val backgroundColor =
+        when {
+            isSelected -> MaterialTheme.colorScheme.primaryContainer.copy(alpha = 0.3f)
+            isFocused -> MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.5f)
+            else -> MaterialTheme.colorScheme.surface
+        }
+
+    Row(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clickable(onClick = onClick)
+                .background(backgroundColor)
+                .padding(horizontal = 12.dp, vertical = 10.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        // Unread indicator
+        if (item.hasUnread) {
+            Box(
+                modifier =
+                    Modifier
+                        .size(8.dp)
+                        .clip(CircleShape)
+                        .background(MaterialTheme.colorScheme.primary),
+            )
+            Spacer(Modifier.width(6.dp))
+        } else {
+            Spacer(Modifier.width(14.dp))
+        }
+
+        // Avatar
+        val firstUser = item.users.firstOrNull()
+        if (firstUser != null) {
+            UserAvatar(
+                userHex = firstUser.pubkeyHex,
+                pictureUrl = firstUser.profilePicture(),
+                size = 40.dp,
+            )
+        } else if (item.isGroup) {
+            Icon(
+                Icons.Default.Group,
+                contentDescription = "Group",
+                modifier = Modifier.size(40.dp),
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+        }
+
+        Spacer(Modifier.width(10.dp))
+
+        // Name, preview, timestamp
+        Column(modifier = Modifier.weight(1f)) {
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.SpaceBetween,
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Text(
+                    text = item.displayName,
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurface,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                    modifier = Modifier.weight(1f, fill = false),
+                )
+
+                if (item.lastMessageTimestamp > 0) {
+                    Text(
+                        text = item.lastMessageTimestamp.toTimeAgo(withDot = false),
+                        style = MaterialTheme.typography.labelSmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.7f),
+                    )
+                }
+            }
+
+            if (item.lastMessagePreview.isNotEmpty()) {
+                Text(
+                    text = item.lastMessagePreview,
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                )
+            }
+
+            // Group indicator
+            if (item.isGroup) {
+                Text(
+                    text = "Group (${item.users.size + 1})",
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.primary.copy(alpha = 0.7f),
+                )
+            }
+        }
+    }
+}
@@ -0,0 +1,181 @@
+/*
+ * 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.ui.chats
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.size
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Email
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.VerticalDivider
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.input.key.Key
+import androidx.compose.ui.input.key.KeyEventType
+import androidx.compose.ui.input.key.isCtrlPressed
+import androidx.compose.ui.input.key.isMetaPressed
+import androidx.compose.ui.input.key.isShiftPressed
+import androidx.compose.ui.input.key.key
+import androidx.compose.ui.input.key.onPreviewKeyEvent
+import androidx.compose.ui.input.key.type
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.commons.model.IAccount
+import com.vitorpamplona.amethyst.commons.model.cache.ICacheProvider
+import com.vitorpamplona.amethyst.commons.viewmodels.ChatNewMessageState
+import com.vitorpamplona.amethyst.commons.viewmodels.ChatroomFeedViewModel
+
+private val isMacOS = System.getProperty("os.name").lowercase().contains("mac")
+
+/**
+ * Desktop DM screen with split-pane layout.
+ *
+ * Left pane (280dp): ConversationListPane with Known/New tabs
+ * Right pane (flex): ChatPane with messages + input, or empty state
+ *
+ * @param account The user's IAccount for DM operations
+ * @param cacheProvider ICacheProvider for user/note lookups
+ * @param onNavigateToProfile Called when navigating to a user profile
+ */
+@Composable
+fun DesktopMessagesScreen(
+    account: IAccount,
+    cacheProvider: ICacheProvider,
+    onNavigateToProfile: (String) -> Unit = {},
+) {
+    val scope = rememberCoroutineScope()
+    val listState =
+        remember(account) {
+            ChatroomListState(account, cacheProvider, scope)
+        }
+    val selectedRoom by listState.selectedRoom.collectAsState()
+    val listFocusRequester = remember { FocusRequester() }
+
+    Row(
+        modifier =
+            Modifier
+                .fillMaxSize()
+                .onPreviewKeyEvent { event ->
+                    if (event.type != KeyEventType.KeyDown) return@onPreviewKeyEvent false
+                    val isModifier = if (isMacOS) event.isMetaPressed else event.isCtrlPressed
+
+                    when {
+                        // Escape -> deselect conversation
+                        event.key == Key.Escape -> {
+                            listState.clearSelection()
+                            true
+                        }
+
+                        // Cmd+Shift+N / Ctrl+Shift+N -> new DM
+                        event.key == Key.N && isModifier && event.isShiftPressed -> {
+                            // TODO: trigger new DM dialog when implemented
+                            true
+                        }
+
+                        else -> {
+                            false
+                        }
+                    }
+                },
+    ) {
+        // Left pane: conversation list (280dp fixed)
+        ConversationListPane(
+            state = listState,
+            selectedRoom = selectedRoom,
+            onConversationSelected = { roomKey ->
+                listState.selectRoom(roomKey)
+            },
+            focusRequester = listFocusRequester,
+        )
+
+        VerticalDivider(modifier = Modifier.fillMaxHeight())
+
+        // Right pane: chat or empty state (flex)
+        Box(modifier = Modifier.weight(1f).fillMaxHeight()) {
+            val currentRoom = selectedRoom
+            if (currentRoom != null) {
+                // Create feed VM and message state scoped to the selected room
+                val feedViewModel =
+                    remember(currentRoom) {
+                        ChatroomFeedViewModel(currentRoom, account, cacheProvider)
+                    }
+                val messageState =
+                    remember(currentRoom) {
+                        ChatNewMessageState(account, cacheProvider, scope)
+                    }
+
+                ChatPane(
+                    roomKey = currentRoom,
+                    account = account,
+                    cacheProvider = cacheProvider,
+                    feedViewModel = feedViewModel,
+                    messageState = messageState,
+                    onNavigateToProfile = onNavigateToProfile,
+                )
+            } else {
+                // Empty state
+                EmptyConversationState()
+            }
+        }
+    }
+}
+
+/**
+ * Shown when no conversation is selected in the right pane.
+ */
+@Composable
+private fun EmptyConversationState() {
+    Box(
+        modifier = Modifier.fillMaxSize(),
+        contentAlignment = Alignment.Center,
+    ) {
+        androidx.compose.foundation.layout.Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+        ) {
+            Icon(
+                Icons.Default.Email,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.3f),
+                modifier = Modifier.size(48.dp),
+            )
+            androidx.compose.foundation.layout.Spacer(
+                modifier = Modifier.height(16.dp),
+            )
+            Text(
+                "Select a conversation to start messaging",
+                style = MaterialTheme.typography.bodyLarge,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+        }
+    }
+}