diff --git a/packages/web/src/components/chat/messageMenuItems.tsx b/packages/web/src/components/chat/messageMenuItems.tsx
new file mode 100644
index 00000000..534c781d
--- /dev/null
+++ b/packages/web/src/components/chat/messageMenuItems.tsx
@@ -0,0 +1,183 @@
+import React from 'react';
+import type { ContextMenuItem } from '../../stores/contextMenuStore';
+import type { MessageWithUser } from '@backspace/shared';
+
+const QUICK_EMOJIS = ['👍', '❤️', '😂', '😮'];
+
+interface MessageMenuParams {
+  message: MessageWithUser;
+  selectedText: string;
+  previousMessageId: string | null;
+  isAuthor: boolean;
+  isDm: boolean;
+  canAddReactions: boolean;
+  canSendMessages: boolean;
+  canManageMessages: boolean;
+  onReply: () => void;
+  onEdit: () => void;
+  onDelete: () => void;
+  onReaction: (emoji: string) => void;
+  onOpenEmojiPicker: () => void;
+  onMarkUnread: (messageId: string) => void;
+}
+
+export function buildMessageMenuItems(params: MessageMenuParams): ContextMenuItem[] {
+  const {
+    message,
+    selectedText,
+    previousMessageId,
+    isAuthor,
+    isDm,
+    canAddReactions,
+    canSendMessages,
+    canManageMessages,
+    onReply,
+    onEdit,
+    onDelete,
+    onReaction,
+    onOpenEmojiPicker,
+    onMarkUnread,
+  } = params;
+
+  const items: ContextMenuItem[] = [];
+
+  // ── Quick Reaction Row ──────────────────────────────────────────────────
+  if (canAddReactions) {
+    items.push({
+      key: 'quick-reactions',
+      type: 'custom',
+      render: () => (
+        <div className="flex items-center gap-1 px-2 py-1.5">
+          {QUICK_EMOJIS.map(emoji => (
+            <button
+              key={emoji}
+              onClick={(e) => {
+                e.stopPropagation();
+                onReaction(emoji);
+              }}
+              className="glass-pill w-9 h-9 flex items-center justify-center text-lg hover:bg-interactive-hover rounded-lg transition-colors"
+            >
+              {emoji}
+            </button>
+          ))}
+          <button
+            onClick={(e) => {
+              e.stopPropagation();
+              onOpenEmojiPicker();
+            }}
+            className="glass-pill w-9 h-9 flex items-center justify-center text-txt-tertiary hover:text-txt-secondary hover:bg-interactive-hover rounded-lg transition-colors"
+            title="Add reaction"
+          >
+            <svg width="18" height="18" viewBox="0 0 24 24" fill="currentColor">
+              <path d="M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm0 18c-4.41 0-8-3.59-8-8s3.59-8 8-8 8 3.59 8 8-3.59 8-8 8zm1-13h-2v4H7v2h4v4h2v-4h4v-2h-4V7z" />
+            </svg>
+          </button>
+        </div>
+      ),
+    });
+    items.push({ key: 'reactions-sep', type: 'separator' });
+  }
+
+  // ── Reply ───────────────────────────────────────────────────────────────
+  const canReply = isDm || canSendMessages;
+  if (canReply) {
+    items.push({
+      key: 'reply',
+      type: 'action',
+      label: 'Reply',
+      icon: (
+        <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+          <path d="M10 9V5L3 12L10 19V14.9C15 14.9 18.5 16.5 21 20C20 15 17 10 10 9Z" />
+        </svg>
+      ),
+      onClick: onReply,
+    });
+    items.push({ key: 'reply-sep', type: 'separator' });
+  }
+
+  // ── Clipboard group ─────────────────────────────────────────────────────
+  items.push({
+    key: 'copy-selected',
+    type: 'action',
+    label: 'Copy Selected Text',
+    hidden: selectedText.length === 0,
+    icon: (
+      <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+        <path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z" />
+      </svg>
+    ),
+    onClick: () => {
+      navigator.clipboard.writeText(selectedText);
+    },
+  });
+
+  items.push({
+    key: 'copy-text',
+    type: 'action',
+    label: 'Copy Text',
+    hidden: !message.content,
+    icon: (
+      <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+        <path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z" />
+      </svg>
+    ),
+    onClick: () => {
+      navigator.clipboard.writeText(message.content ?? '');
+    },
+  });
+
+  items.push({ key: 'clipboard-sep', type: 'separator' });
+
+  // ── Mark Unread ─────────────────────────────────────────────────────────
+  items.push({
+    key: 'mark-unread',
+    type: 'action',
+    label: 'Mark Unread',
+    icon: (
+      <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+        <path d="M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm0 18c-4.41 0-8-3.59-8-8s3.59-8 8-8 8 3.59 8 8-3.59 8-8 8z" />
+        <circle cx="12" cy="12" r="5" />
+      </svg>
+    ),
+    onClick: () => {
+      // '0' sentinel marks the entire channel as unread (when no previous message exists)
+      onMarkUnread(previousMessageId ?? '0');
+    },
+  });
+
+  items.push({ key: 'unread-sep', type: 'separator' });
+
+  // ── Edit Message (author only) ──────────────────────────────────────────
+  if (isAuthor) {
+    items.push({
+      key: 'edit',
+      type: 'action',
+      label: 'Edit Message',
+      icon: (
+        <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+          <path d="M3 17.25V21h3.75L17.81 9.94l-3.75-3.75L3 17.25zM20.71 7.04c.39-.39.39-1.02 0-1.41l-2.34-2.34c-.39-.39-1.02-.39-1.41 0l-1.83 1.83 3.75 3.75 1.83-1.83z" />
+        </svg>
+      ),
+      onClick: onEdit,
+    });
+  }
+
+  // ── Delete Message (author or moderator) ────────────────────────────────
+  const canDelete = isAuthor || canManageMessages;
+  if (canDelete) {
+    items.push({
+      key: 'delete',
+      type: 'action',
+      label: 'Delete Message',
+      icon: (
+        <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+          <path d="M6 19c0 1.1.9 2 2 2h8c1.1 0 2-.9 2-2V7H6v12zM19 4h-3.5l-1-1h-5l-1 1H5v2h14V4z" />
+        </svg>
+      ),
+      onClick: onDelete,
+      danger: true,
+    });
+  }
+
+  return items;
+}