diff --git a/src/components/layout/ChannelList.tsx b/src/components/layout/ChannelList.tsx
index fbd63b77..d0bcc29b 100644
--- a/src/components/layout/ChannelList.tsx
+++ b/src/components/layout/ChannelList.tsx
@@ -752,9 +752,9 @@ export const ChannelList: React.FC<{
                             ) : (
                               selectedChannelId !== channel.id &&
                               (channel.isMentioned &&
-                              channel.unreadCount > 0 ? (
+                              (channel.mentionCount ?? 0) > 0 ? (
                                 <span className="bg-red-500 text-white text-xs font-bold rounded-full px-1.5 py-0.5 min-w-[20px] text-center">
-                                  {channel.unreadCount}
+                                  {channel.mentionCount}
                                 </span>
                               ) : channel.unreadCount > 0 ? (
                                 <span className="w-2 h-2 bg-blue-500 rounded-full" />
@@ -1202,9 +1202,9 @@ export const ChannelList: React.FC<{
                           {/* Unread/Mention indicators */}
                           {selectedPrivateChatId !== privateChat.id &&
                             (privateChat.isMentioned &&
-                            privateChat.unreadCount > 0 ? (
+                            (privateChat.mentionCount ?? 0) > 0 ? (
                               <span className="bg-red-500 text-white text-xs font-bold rounded-full px-1.5 py-0.5 min-w-[20px] text-center">
-                                {privateChat.unreadCount}
+                                {privateChat.mentionCount}
                               </span>
                             ) : privateChat.unreadCount > 0 ? (
                               <span className="w-2 h-2 bg-blue-500 rounded-full" />
diff --git a/src/components/layout/ChatArea.tsx b/src/components/layout/ChatArea.tsx
index 2509eda7..ddc410bf 100644
--- a/src/components/layout/ChatArea.tsx
+++ b/src/components/layout/ChatArea.tsx
@@ -42,6 +42,10 @@ import { MiniMediaPlayer } from "../ui/MiniMediaPlayer";
 import ModerationModal, { type ModerationAction } from "../ui/ModerationModal";
 import ReactionModal from "../ui/ReactionModal";
 import { ReactionPopover } from "../ui/ReactionPopover";
+import {
+  getActiveSlashQuery,
+  SlashCommandPopover,
+} from "../ui/SlashCommandPopover";
 import { TextArea } from "../ui/TextInput";
 import { TopicMediaStrip } from "../ui/TopicMediaStrip";
 import UserContextMenu from "../ui/UserContextMenu";
@@ -108,6 +112,10 @@ export const ChatArea: React.FC<{
   // autocompleteInputText is updated only when autocomplete dropdowns are visible.
   const [hasText, setHasText] = useState(false);
   const [autocompleteInputText, setAutocompleteInputText] = useState("");
+  // Slash-command popover state.  Only updated when the input starts
+  // with "/" and we're still completing the command name -- otherwise
+  // typing wouldn't trigger a re-render for this popover at all.
+  const [slashInputValue, setSlashInputValue] = useState("");
   const [isEmojiSelectorOpen, setIsEmojiSelectorOpen] = useState(false);
   const [isColorPickerOpen, setIsColorPickerOpen] = useState(false);
   const [selectedColor, setSelectedColor] = useState<string | null>(null);
@@ -1286,6 +1294,18 @@ export const ChatArea: React.FC<{
     cursorPositionRef.current = newCursorPosition;
     handleUpdatedText(newText);
 
+    // obsidianirc/cmdslist: update slash state only when relevant.
+    // When the input doesn't look like a command (no leading slash,
+    // or already past the command name), re-render only on the
+    // active->inactive transition to clear the popover.
+    const slashActive =
+      getActiveSlashQuery(newText, newCursorPosition) !== null;
+    if (slashActive) {
+      setSlashInputValue(newText);
+    } else if (slashInputValue !== "") {
+      setSlashInputValue("");
+    }
+
     // Exit history mode if user starts typing
     messageHistory.exitHistory();
 
@@ -2138,6 +2158,42 @@ export const ChatArea: React.FC<{
                 inputElement={inputRef.current}
               />
 
+              {/* obsidianirc/cmdslist: slash-command suggestion popover */}
+              {(() => {
+                const srv = servers.find((s) => s.id === selectedServerId);
+                const cmds = srv?.cmdsAvailable ?? [];
+                if (cmds.length === 0) return null;
+                const slashActive =
+                  getActiveSlashQuery(
+                    slashInputValue,
+                    cursorPositionRef.current,
+                  ) !== null;
+                return (
+                  <SlashCommandPopover
+                    isVisible={slashActive}
+                    inputValue={slashInputValue}
+                    commands={cmds}
+                    inputElement={inputRef.current}
+                    onSelect={(cmd) => {
+                      // Replace the partial command with /<cmd> + space
+                      // and put the cursor right after the space.
+                      const next = `/${cmd} `;
+                      applyText(next);
+                      cursorPositionRef.current = next.length;
+                      setSlashInputValue("");
+                      inputRef.current?.focus();
+                      inputRef.current?.setSelectionRange(
+                        next.length,
+                        next.length,
+                      );
+                    }}
+                    onClose={() => {
+                      setSlashInputValue("");
+                    }}
+                  />
+                );
+              })()}
+
               {/* Members dropdown triggered by @ button */}
               <AutocompleteDropdown
                 isNarrowView={isNarrowView}
diff --git a/src/components/ui/SlashCommandPopover.tsx b/src/components/ui/SlashCommandPopover.tsx
new file mode 100644
index 00000000..42d28568
--- /dev/null
+++ b/src/components/ui/SlashCommandPopover.tsx
@@ -0,0 +1,140 @@
+// Slash-command suggestion popover, anchored above the chat input.
+//
+// Activates when the input value starts with "/" and the user is still
+// typing the command name (no space yet).  Filters the server's
+// cmdsAvailable set (populated by the obsidianirc/cmdslist cap) by
+// prefix match.
+//
+// Keyboard:
+//   ArrowUp / ArrowDown -- cycle highlighted suggestion
+//   Tab / Enter         -- accept current suggestion
+//   Escape              -- close
+//
+// onSelect receives the bare command name (without the leading slash).
+
+import type React from "react";
+import { useEffect, useMemo, useRef, useState } from "react";
+
+interface SlashCommandPopoverProps {
+  isVisible: boolean;
+  inputValue: string;
+  commands: string[];
+  inputElement?: HTMLInputElement | HTMLTextAreaElement | null;
+  onSelect: (command: string) => void;
+  onClose: () => void;
+}
+
+const MAX_SUGGESTIONS = 10;
+
+export function getActiveSlashQuery(
+  inputValue: string,
+  cursorPosition: number,
+): string | null {
+  // Only active when the input starts with a single "/" and the user
+  // has not yet typed a space (still completing the command name).
+  if (!inputValue.startsWith("/")) return null;
+  if (inputValue.startsWith("//")) return null; // escape for literal "/"
+  const beforeCursor = inputValue.slice(0, cursorPosition);
+  const firstSpace = beforeCursor.indexOf(" ");
+  if (firstSpace !== -1) return null;
+  return beforeCursor.slice(1).toLowerCase();
+}
+
+export const SlashCommandPopover: React.FC<SlashCommandPopoverProps> = ({
+  isVisible,
+  inputValue,
+  commands,
+  inputElement,
+  onSelect,
+  onClose,
+}) => {
+  const cursorPosition = inputElement?.selectionStart ?? inputValue.length;
+  const query = getActiveSlashQuery(inputValue, cursorPosition);
+  const [selectedIndex, setSelectedIndex] = useState(0);
+  const ref = useRef<HTMLDivElement>(null);
+
+  const matches = useMemo(() => {
+    if (query === null) return [] as string[];
+    if (commands.length === 0) return [];
+    return commands
+      .filter((c) => c.startsWith(query))
+      .slice(0, MAX_SUGGESTIONS);
+  }, [commands, query]);
+
+  // Reset highlight when the match set changes.
+  // biome-ignore lint/correctness/useExhaustiveDependencies: matches identity changes drive the reset
+  useEffect(() => {
+    setSelectedIndex(0);
+  }, [matches.length, query]);
+
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      if (!isVisible || matches.length === 0) return;
+      switch (e.key) {
+        case "ArrowDown":
+          e.preventDefault();
+          e.stopPropagation();
+          setSelectedIndex((i) => (i + 1) % matches.length);
+          break;
+        case "ArrowUp":
+          e.preventDefault();
+          e.stopPropagation();
+          setSelectedIndex((i) => (i === 0 ? matches.length - 1 : i - 1));
+          break;
+        case "Tab":
+        case "Enter":
+          e.preventDefault();
+          e.stopPropagation();
+          if (matches[selectedIndex]) onSelect(matches[selectedIndex]);
+          break;
+        case "Escape":
+          e.preventDefault();
+          e.stopPropagation();
+          onClose();
+          break;
+      }
+    };
+    document.addEventListener("keydown", onKey, true);
+    return () => document.removeEventListener("keydown", onKey, true);
+  }, [isVisible, matches, selectedIndex, onSelect, onClose]);
+
+  if (!isVisible || query === null || matches.length === 0) return null;
+
+  // Position above the input box, left-aligned.
+  const inputRect = inputElement?.getBoundingClientRect();
+  const top = inputRect
+    ? inputRect.top + window.scrollY - matches.length * 32 - 32
+    : 100;
+  const left = inputRect ? inputRect.left + window.scrollX : 100;
+
+  return (
+    <div
+      ref={ref}
+      className="fixed z-[9999] bg-discord-dark-300 border border-discord-dark-500 rounded-md shadow-xl min-w-56 max-w-md"
+      style={{ top, left }}
+    >
+      <div className="py-1 max-h-60 overflow-y-auto">
+        <div className="px-3 py-1 text-xs text-discord-text-muted font-semibold uppercase tracking-wide border-b border-discord-dark-500">
+          Slash commands
+        </div>
+        {matches.map((cmd, index) => (
+          <div
+            key={cmd}
+            data-cmd-index={index}
+            className={`px-3 py-1.5 cursor-pointer flex items-center gap-2 transition-colors duration-150 ${
+              index === selectedIndex
+                ? "bg-discord-text-link text-white"
+                : "text-discord-text-normal hover:bg-discord-dark-200 hover:text-white"
+            }`}
+            onClick={() => onSelect(cmd)}
+            onMouseEnter={() => setSelectedIndex(index)}
+          >
+            <span className="font-mono text-sm">/{cmd}</span>
+          </div>
+        ))}
+      </div>
+    </div>
+  );
+};
+
+export default SlashCommandPopover;
diff --git a/src/components/ui/TopicModal.tsx b/src/components/ui/TopicModal.tsx
index cd225f39..fa26bf0a 100644
--- a/src/components/ui/TopicModal.tsx
+++ b/src/components/ui/TopicModal.tsx
@@ -1,10 +1,11 @@
 import type React from "react";
-import { useState } from "react";
+import { Fragment, useState } from "react";
 import ircClient from "../../lib/ircClient";
 import { hasOpPermission } from "../../lib/ircUtils";
 import BaseModal from "../../lib/modal/BaseModal";
 import { Button, ModalBody, ModalFooter } from "../../lib/modal/components";
 import type { Channel, User } from "../../types";
+import { EnhancedLinkWrapper } from "./LinkWrapper";
 import { TextArea } from "./TextInput";
 
 interface TopicModalProps {
@@ -15,6 +16,46 @@ interface TopicModalProps {
   currentUser: User | null;
 }
 
+// Render plain topic text with http/https/irc URLs as <a> tags carrying
+// the "external-link-security" / "irc-link" classes, so EnhancedLinkWrapper
+// intercepts the click and routes through ExternalLinkWarningModal /
+// onIrcLinkClick (matching the message-rendering flow).
+const URL_RX = /\b(?:https?|ircs?):\/\/[^\s<>"'`]+/gi;
+
+function renderTopicWithLinks(text: string): React.ReactNode[] {
+  const out: React.ReactNode[] = [];
+  let last = 0;
+  let i = 0;
+  for (const match of text.matchAll(URL_RX)) {
+    const idx = match.index ?? -1;
+    if (idx < 0) continue;
+    if (idx > last) {
+      out.push(<Fragment key={`t-${i}`}>{text.slice(last, idx)}</Fragment>);
+    }
+    const url = match[0];
+    const isIrc = url.startsWith("irc://") || url.startsWith("ircs://");
+    out.push(
+      <a
+        key={`u-${i++}`}
+        href={url}
+        target="_blank"
+        rel="noopener noreferrer"
+        className={`underline text-blue-400 hover:text-blue-300 break-all ${
+          isIrc ? "irc-link" : "external-link-security"
+        }`}
+      >
+        {url}
+      </a>,
+    );
+    last = idx + url.length;
+  }
+  if (last < text.length) {
+    out.push(<Fragment key="tail">{text.slice(last)}</Fragment>);
+  }
+  if (out.length === 0) return [text];
+  return out;
+}
+
 export const TopicModal: React.FC<TopicModalProps> = ({
   isOpen,
   onClose,
@@ -43,18 +84,31 @@ export const TopicModal: React.FC<TopicModalProps> = ({
       maxWidth="md"
     >
       <ModalBody>
-        <TextArea
-          value={editedTopic}
-          onChange={(e) => setEditedTopic(e.target.value)}
-          readOnly={!canEdit}
-          className={`w-full p-3 rounded min-h-[120px] resize-y text-sm leading-relaxed focus:outline-none transition-colors ${
-            canEdit
-              ? "bg-discord-dark-400 text-white focus:ring-1 focus:ring-discord-primary"
-              : "bg-discord-dark-400/60 text-discord-text-muted cursor-default select-all"
-          }`}
-          placeholder={canEdit ? "Set a topic…" : "No topic set"}
-          autoFocus={canEdit}
-        />
+        {canEdit ? (
+          <TextArea
+            value={editedTopic}
+            onChange={(e) => setEditedTopic(e.target.value)}
+            className="w-full p-3 rounded min-h-[120px] resize-y text-sm leading-relaxed focus:outline-none transition-colors bg-discord-dark-400 text-white focus:ring-1 focus:ring-discord-primary"
+            placeholder="Set a topic…"
+            autoFocus
+          />
+        ) : (
+          // Read-only path: render as a div with linkified URLs so the
+          // text doesn't sit inside a textarea (which strips markup and
+          // can't have clickable links).
+          <EnhancedLinkWrapper>
+            <section
+              className="w-full p-3 rounded min-h-[120px] text-sm leading-relaxed bg-discord-dark-400/60 text-discord-text-muted whitespace-pre-wrap break-words select-text"
+              aria-label="Channel topic"
+            >
+              {channel.topic ? (
+                renderTopicWithLinks(channel.topic)
+              ) : (
+                <span className="italic">No topic set</span>
+              )}
+            </section>
+          </EnhancedLinkWrapper>
+        )}
       </ModalBody>
 
       {canEdit && (
diff --git a/src/hooks/useMessageSending.ts b/src/hooks/useMessageSending.ts
index 9763e1f4..576fcf70 100644
--- a/src/hooks/useMessageSending.ts
+++ b/src/hooks/useMessageSending.ts
@@ -271,7 +271,10 @@ export function useMessageSending({
             10;
 
           if (formattedLine.length > maxLineLengthForTarget) {
-            const splitLines = splitLongMessage(formattedLine, target);
+            // preserveBoundarySpace=true so concat reconstructs the
+            // original spacing.  Without it the receiver sees
+            // "AAA BBBCCC" instead of "AAA BBB CCC".
+            const splitLines = splitLongMessage(formattedLine, target, true);
             splitLines.forEach((splitLine: string, index: number) => {
               if (index === 0) {
                 ircClient.sendRaw(
@@ -298,7 +301,7 @@ export function useMessageSending({
           formatting: selectedFormatting,
         });
 
-        const splitLines = splitLongMessage(formattedText, target);
+        const splitLines = splitLongMessage(formattedText, target, true);
         splitLines.forEach((splitLine: string, index: number) => {
           if (index === 0) {
             ircClient.sendRaw(
diff --git a/src/lib/irc/IRCClient.ts b/src/lib/irc/IRCClient.ts
index 5b1d500e..b8d7857d 100644
--- a/src/lib/irc/IRCClient.ts
+++ b/src/lib/irc/IRCClient.ts
@@ -245,6 +245,13 @@ export interface EventMap {
     serviceName: string;
     jwtToken: string;
   };
+  // obsidianirc/cmdslist: server is reporting an add/remove delta of
+  // commands the user can invoke right now.  Ops are individual
+  // tokens of the form "+cmd" or "-cmd" (multiple per wire line).
+  CMDSLIST: BaseIRCEvent & {
+    additions: string[];
+    removals: string[];
+  };
   WHOIS_BOT: {
     serverId: string;
     nick: string;
@@ -470,6 +477,7 @@ export class IRCClient implements IRCClientContext {
     "invite-notify",
     "monitor",
     "extended-monitor",
+    "obsidianirc/cmdslist",
     // Note: unrealircd.org/link-security is informational only, don't request it
   ];
 
diff --git a/src/lib/irc/handlers/cmdslist.ts b/src/lib/irc/handlers/cmdslist.ts
new file mode 100644
index 00000000..d383110c
--- /dev/null
+++ b/src/lib/irc/handlers/cmdslist.ts
@@ -0,0 +1,33 @@
+// obsidianirc/cmdslist: parse the per-line CMDSLIST add/remove
+// payload into a single typed event.
+//
+// Wire format:
+//   :server CMDSLIST +foo +bar -baz +quux
+//
+// Each parameter token is "+<cmd>" or "-<cmd>".  We separate them so
+// the store can union-and-difference its existing set without having
+// to re-walk every entry.
+
+import type { IRCClientContext } from "../IRCClientContext";
+
+export function handleCmdslist(
+  ctx: IRCClientContext,
+  serverId: string,
+  _source: string,
+  parv: string[],
+  _mtags: Record<string, string> | undefined,
+): void {
+  const additions: string[] = [];
+  const removals: string[] = [];
+  for (const tok of parv) {
+    if (!tok) continue;
+    if (tok[0] === "+") {
+      const name = tok.slice(1).trim();
+      if (name) additions.push(name);
+    } else if (tok[0] === "-") {
+      const name = tok.slice(1).trim();
+      if (name) removals.push(name);
+    }
+  }
+  ctx.triggerEvent("CMDSLIST", { serverId, additions, removals });
+}
diff --git a/src/lib/irc/handlers/index.ts b/src/lib/irc/handlers/index.ts
index 15aaf834..cb5baa3c 100644
--- a/src/lib/irc/handlers/index.ts
+++ b/src/lib/irc/handlers/index.ts
@@ -27,6 +27,7 @@ import {
   handleRplTopicWhoTime,
   handleTopic,
 } from "./channels";
+import { handleCmdslist } from "./cmdslist";
 import {
   handleCap,
   handleError,
@@ -288,6 +289,8 @@ export const IRC_DISPATCH: Record<string, HandlerFn> = {
     handleVerify(ctx, serverId, source, parv, mtags),
   EXTJWT: (ctx, serverId, source, parv, mtags) =>
     handleExtjwt(ctx, serverId, source, parv, mtags),
+  CMDSLIST: (ctx, serverId, source, parv, mtags) =>
+    handleCmdslist(ctx, serverId, source, parv, mtags),
 
   "730": (ctx, serverId, source, parv, mtags) =>
     handleMonOnline(ctx, serverId, source, parv, mtags),
diff --git a/src/lib/messageProtocol.ts b/src/lib/messageProtocol.ts
index e2837dcd..317dcbc6 100644
--- a/src/lib/messageProtocol.ts
+++ b/src/lib/messageProtocol.ts
@@ -6,16 +6,26 @@
  * Helper function to split long messages while respecting IRC protocol limits
  * @param message - The message to split
  * @param target - The channel or username target
+ * @param preserveBoundarySpace - When true, each non-final chunk
+ *   carries the original boundary space at its trailing edge so a
+ *   downstream draft/multiline-concat join reconstructs the original
+ *   text with its spacing intact.  Default false preserves the legacy
+ *   "send as independent PRIVMSGs" behaviour where the split-point
+ *   space simply becomes a line break.
  * @returns Array of message chunks within IRC limits
  */
 export const splitLongMessage = (
   message: string,
   target = "#channel",
+  preserveBoundarySpace = false,
 ): string[] => {
   const protocolOverhead = calculateProtocolOverhead(target);
 
-  // Available space for the actual message content
-  const maxMessageLength = 512 - protocolOverhead;
+  // Available space for the actual message content.  Reserve one byte
+  // when we're going to re-attach a boundary space so the wire line
+  // still fits inside the 512-byte IRC limit.
+  const maxMessageLength =
+    512 - protocolOverhead - (preserveBoundarySpace ? 1 : 0);
 
   if (message.length <= maxMessageLength) {
     return [message];
@@ -52,7 +62,11 @@ export const splitLongMessage = (
     lines.push(currentLine);
   }
 
-  return lines.filter((line) => line.length > 0);
+  const filtered = lines.filter((line) => line.length > 0);
+  if (!preserveBoundarySpace || filtered.length < 2) return filtered;
+  return filtered.map((line, idx) =>
+    idx < filtered.length - 1 ? `${line} ` : line,
+  );
 };
 
 /**
diff --git a/src/store/handlers/auth.ts b/src/store/handlers/auth.ts
index d383166c..7943a163 100644
--- a/src/store/handlers/auth.ts
+++ b/src/store/handlers/auth.ts
@@ -337,4 +337,19 @@ export function registerAuthHandlers(store: StoreApi<AppState>): void {
       });
     },
   );
+
+  // obsidianirc/cmdslist: maintain a lowercase set of invocable
+  // commands per server.  Additions and removals can arrive in the
+  // same wire line, so apply both atomically.
+  ircClient.on("CMDSLIST", ({ serverId, additions, removals }) => {
+    store.setState((state) => ({
+      servers: state.servers.map((server) => {
+        if (server.id !== serverId) return server;
+        const next = new Set(server.cmdsAvailable ?? []);
+        for (const cmd of additions) next.add(cmd.toLowerCase());
+        for (const cmd of removals) next.delete(cmd.toLowerCase());
+        return { ...server, cmdsAvailable: Array.from(next).sort() };
+      }),
+    }));
+  });
 }
diff --git a/src/store/handlers/messages.ts b/src/store/handlers/messages.ts
index 68f3644e..193c13f9 100644
--- a/src/store/handlers/messages.ts
+++ b/src/store/handlers/messages.ts
@@ -151,6 +151,8 @@ export function registerMessageHandlers(store: StoreApi<AppState>): void {
                     return {
                       ...ch,
                       unreadCount: ch.unreadCount + 1,
+                      mentionCount:
+                        (ch.mentionCount ?? 0) + (hasMention ? 1 : 0),
                       isMentioned: hasMention || ch.isMentioned,
                     };
                   }
@@ -906,13 +908,12 @@ export function registerMessageHandlers(store: StoreApi<AppState>): void {
                     const isActive =
                       getCurrentSelection(state).selectedPrivateChatId ===
                       pc.id;
+                    const reset = isActive || isHistoricalMessage;
                     return {
                       ...pc,
                       lastActivity: new Date(),
-                      unreadCount:
-                        isActive || isHistoricalMessage
-                          ? 0
-                          : pc.unreadCount + 1,
+                      unreadCount: reset ? 0 : pc.unreadCount + 1,
+                      mentionCount: reset ? 0 : (pc.mentionCount ?? 0) + 1,
                       isMentioned: !isHistoricalMessage && true, // All PMs are considered mentions (except historical)
                     };
                   }
@@ -1337,11 +1338,12 @@ export function registerMessageHandlers(store: StoreApi<AppState>): void {
                 if (pc.id === privateChat.id) {
                   const isActive =
                     getCurrentSelection(state).selectedPrivateChatId === pc.id;
+                  const reset = isActive || isHistoricalMessage;
                   return {
                     ...pc,
                     lastActivity: new Date(),
-                    unreadCount:
-                      isActive || isHistoricalMessage ? 0 : pc.unreadCount + 1,
+                    unreadCount: reset ? 0 : pc.unreadCount + 1,
+                    mentionCount: reset ? 0 : (pc.mentionCount ?? 0) + 1,
                     isMentioned: !isHistoricalMessage && true, // All PMs are considered mentions (except historical)
                   };
                 }
diff --git a/src/store/index.ts b/src/store/index.ts
index 7ef1cff3..04acaaa4 100644
--- a/src/store/index.ts
+++ b/src/store/index.ts
@@ -1602,7 +1602,55 @@ const useStore = create<AppState>((set, get) => ({
         server?.privateChats?.find((pc) => pc.id === selectedPrivateChatId)
           ?.username || null;
 
+      // When the user switches *to* a server, the channel or PM that
+      // restores into focus has now been "looked at" -- clear its
+      // unread / mention indicators.  Without this the badge sticks
+      // on the just-foregrounded buffer until the user clicks somewhere
+      // else and back.
+      let updatedServers = state.servers;
+      if (selectedChannelId || selectedPrivateChatId) {
+        updatedServers = state.servers.map((s) => {
+          if (s.id !== serverId) return s;
+          let touched = false;
+          const channels = s.channels.map((ch) => {
+            if (ch.id !== selectedChannelId) return ch;
+            if (
+              ch.unreadCount === 0 &&
+              !ch.isMentioned &&
+              (ch.mentionCount ?? 0) === 0
+            )
+              return ch;
+            touched = true;
+            return {
+              ...ch,
+              unreadCount: 0,
+              mentionCount: 0,
+              isMentioned: false,
+            };
+          });
+          const privateChats = s.privateChats?.map((pc) => {
+            if (pc.id !== selectedPrivateChatId) return pc;
+            if (
+              pc.unreadCount === 0 &&
+              !pc.isMentioned &&
+              (pc.mentionCount ?? 0) === 0
+            )
+              return pc;
+            touched = true;
+            return {
+              ...pc,
+              unreadCount: 0,
+              mentionCount: 0,
+              isMentioned: false,
+            };
+          });
+          if (!touched) return s;
+          return { ...s, channels, privateChats };
+        });
+      }
+
       return {
+        servers: updatedServers,
         ui: {
           ...state.ui,
           selectedServerId: serverId,
@@ -1697,6 +1745,7 @@ const useStore = create<AppState>((set, get) => ({
                 return {
                   ...channel,
                   unreadCount: 0,
+                  mentionCount: 0,
                   isMentioned: false,
                 };
               }
@@ -1784,6 +1833,7 @@ const useStore = create<AppState>((set, get) => ({
               return {
                 ...channel,
                 unreadCount: 0,
+                mentionCount: 0,
                 isMentioned: false,
               };
             }
@@ -1891,6 +1941,7 @@ const useStore = create<AppState>((set, get) => ({
                   return {
                     ...privateChat,
                     unreadCount: 0,
+                    mentionCount: 0,
                     isMentioned: false,
                   };
                 }
diff --git a/src/types/index.ts b/src/types/index.ts
index d5694eff..8d66cef7 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -46,6 +46,10 @@ export interface Server {
   jwtToken?: string; // JWT token for filehost authentication
   isUnrealIRCd?: boolean; // Whether this server is running UnrealIRCd
   elist?: string; // ELIST ISUPPORT value for extended LIST capabilities
+  // obsidianirc/cmdslist: lowercase set of commands this user can
+  // currently invoke on this server.  Used to drive the slash-command
+  // suggestion popover.  undefined = the cap is not negotiated.
+  cmdsAvailable?: string[];
 }
 
 export interface ServerConfig {
@@ -74,6 +78,11 @@ export interface Channel {
   isPrivate: boolean;
   serverId: string;
   unreadCount: number;
+  // Number of *highlight* events since the channel was last marked
+  // read.  Distinct from unreadCount (every message) so the badge
+  // can show "you were pinged 3 times" instead of "33 messages
+  // happened since your first ping".
+  mentionCount?: number;
   isMentioned: boolean;
   messages: Message[];
   users: User[];
@@ -95,6 +104,8 @@ export interface PrivateChat {
   username: string;
   serverId: string;
   unreadCount: number;
+  // Highlight counter (PMs always count as mentions; this is per-PM).
+  mentionCount?: number;
   isMentioned: boolean;
   lastActivity?: Date;
   isPinned?: boolean;