diff --git a/src/lib/chat.svelte.ts b/src/lib/chat.svelte.ts
index 4dab4e1..49f42e8 100644
--- a/src/lib/chat.svelte.ts
+++ b/src/lib/chat.svelte.ts
@@ -3,6 +3,7 @@ import { loadNostrUser, type NostrUser } from "@nostr/gadgets/metadata";
 import { RELAY_URL, GROUP_ID } from "$lib/config";
 import { auth } from "$lib/auth.svelte";
 import { ingestNostrUser } from "$lib/profiles.svelte";
+import { extractMentionPubkeys, buildPTagHints } from "$lib/mentions";
 
 export type ChatMessageData = {
   id: string;
@@ -114,10 +115,21 @@ export async function sendChatMessage(
     .slice(-3)
     .map((m) => m.id.slice(0, 8));
 
+  const notifyPubkeys = new Set<string>();
+  for (const pk of extractMentionPubkeys(content)) notifyPubkeys.add(pk);
+  if (replyTo && replyTo.pubkey !== ownPubkey)
+    notifyPubkeys.add(replyTo.pubkey);
+  notifyPubkeys.delete(ownPubkey);
+
+  const hints = await buildPTagHints(notifyPubkeys);
+
   const tags: string[][] = [["h", GROUP_ID]];
   if (replyTo) {
     tags.push(["q", replyTo.id, RELAY_URL, replyTo.pubkey]);
-    if (replyTo.pubkey !== ownPubkey) tags.push(["p", replyTo.pubkey]);
+  }
+  for (const pk of notifyPubkeys) {
+    const hint = hints.get(pk);
+    tags.push(hint ? ["p", pk, hint] : ["p", pk]);
   }
   if (previousRefs.length > 0) tags.push(["previous", ...previousRefs]);
 
diff --git a/src/lib/components/ChatContent.svelte b/src/lib/components/ChatContent.svelte
new file mode 100644
index 0000000..0d68766
--- /dev/null
+++ b/src/lib/components/ChatContent.svelte
@@ -0,0 +1,81 @@
+<script lang="ts">
+  import * as nip19 from "@nostr/tools/nip19";
+  import { loadNostrUser, type NostrUser } from "@nostr/gadgets/metadata";
+
+  type Props = {
+    content: string;
+    profiles?: Record<string, NostrUser>;
+  };
+
+  let { content, profiles = {} }: Props = $props();
+
+  type Token =
+    | { type: "text"; value: string }
+    | { type: "mention"; pubkey: string; entity: string; fallback: string };
+
+  const MENTION_RE = /nostr:(npub1[a-z0-9]+|nprofile1[a-z0-9]+)/gi;
+
+  function shortEntity(entity: string): string {
+    const m = entity.match(/^(npub|nprofile)1/);
+    if (!m) return entity;
+    const prefix = m[0];
+    const rest = entity.slice(prefix.length);
+    if (rest.length <= 12) return entity;
+    return `${prefix}${rest.slice(0, 6)}…${rest.slice(-4)}`;
+  }
+
+  const tokens = $derived.by<Token[]>(() => {
+    const out: Token[] = [];
+    let last = 0;
+    for (const m of content.matchAll(MENTION_RE)) {
+      const start = m.index ?? 0;
+      const entity = m[1].toLowerCase();
+      let pubkey: string | null = null;
+      try {
+        const decoded = nip19.decode(entity);
+        if (decoded.type === "npub") pubkey = decoded.data;
+        else if (decoded.type === "nprofile") pubkey = decoded.data.pubkey;
+      } catch {
+        // Invalid bech32, fall through to text
+      }
+      if (start > last)
+        out.push({ type: "text", value: content.slice(last, start) });
+      if (pubkey) {
+        out.push({
+          type: "mention",
+          pubkey,
+          entity,
+          fallback: shortEntity(entity),
+        });
+      } else {
+        out.push({ type: "text", value: m[0] });
+      }
+      last = start + m[0].length;
+    }
+    if (last < content.length)
+      out.push({ type: "text", value: content.slice(last) });
+    return out;
+  });
+
+  let resolvedUsers = $state<Record<string, NostrUser>>({});
+
+  $effect(() => {
+    for (const t of tokens) {
+      if (t.type !== "mention") continue;
+      if (resolvedUsers[t.pubkey] || profiles[t.pubkey]) continue;
+      loadNostrUser(t.pubkey).then((u) => {
+        resolvedUsers = { ...resolvedUsers, [t.pubkey]: u };
+      });
+    }
+  });
+</script>
+
+<span class="break-words whitespace-pre-wrap"
+  >{#each tokens as t (t)}{#if t.type === "mention"}{@const u =
+        profiles[t.pubkey] ?? resolvedUsers[t.pubkey]}<a
+        href="https://njump.me/{t.entity}"
+        target="_blank"
+        rel="noopener noreferrer"
+        class="text-brand hover:underline">@{u?.shortName ?? t.fallback}</a
+      >{:else}{t.value}{/if}{/each}</span
+>
diff --git a/src/lib/components/ChatSidebar.svelte b/src/lib/components/ChatSidebar.svelte
index e6bc261..4d52377 100644
--- a/src/lib/components/ChatSidebar.svelte
+++ b/src/lib/components/ChatSidebar.svelte
@@ -9,6 +9,8 @@
   import { auth, openLogin } from "$lib/auth.svelte";
   import { withJoin } from "$lib/join.svelte";
   import type { NostrUser } from "@nostr/gadgets/metadata";
+  import MentionAutocomplete from "$lib/components/MentionAutocomplete.svelte";
+  import ChatContent from "$lib/components/ChatContent.svelte";
 
   type Props = {
     expanded?: boolean;
@@ -19,7 +21,7 @@
 
   let asideEl: HTMLElement;
   let listEl = $state<HTMLDivElement | null>(null);
-  let inputEl = $state<HTMLTextAreaElement | null>(null);
+  let inputEl = $state<MentionAutocomplete | null>(null);
   let openMenuId = $state<string | null>(null);
   let replyTarget = $state<ChatMessageData | null>(null);
   let inputValue = $state("");
@@ -29,6 +31,9 @@
   const messages = $derived(chatStore.messages);
   const profiles = $derived(chatStore.profiles);
 
+  // Distinct authors of loaded messages — power the @ autocomplete context.
+  const contextPubkeys = $derived([...new Set(messages.map((m) => m.pubkey))]);
+
   function resolveAuthor(pubkey: string) {
     const u: NostrUser | undefined = profiles[pubkey];
     return {
@@ -45,7 +50,9 @@
   }
 
   function truncate(s: string, n = 60) {
-    const t = s.replace(/\s+/g, " ").trim();
+    // Collapse mentions to @… so the preview stays readable.
+    const stripped = s.replace(/nostr:(?:npub1|nprofile1)[a-z0-9]+/gi, "@…");
+    const t = stripped.replace(/\s+/g, " ").trim();
     return t.length > n ? t.slice(0, n) + "…" : t;
   }
 
@@ -137,14 +144,14 @@
 
 <aside
   bind:this={asideEl}
-  class="absolute right-0 top-2 h-[calc(100%-0.5rem)] z-10 flex flex-col rounded-tl-xl min-[1540px]:rounded-tr-xl bg-white transition-all duration-200
+  class="absolute top-2 right-0 z-10 flex h-[calc(100%-0.5rem)] flex-col rounded-tl-xl bg-white transition-all duration-200 min-[1540px]:rounded-tr-xl
 		{expanded ? 'w-150 shadow-2xl' : 'w-80 shadow-lg'} px-6 py-6"
 >
-  <div class="flex shrink-0 items-center justify-between mb-6">
-    <span class="text-[1.5rem] text-brand leading-7">Chat</span>
+  <div class="mb-6 flex shrink-0 items-center justify-between">
+    <span class="text-brand text-[1.5rem] leading-7">Chat</span>
     <button
       onclick={onToggle}
-      class="rounded bg-neutral-100 hover:bg-neutral-200 transition-colors"
+      class="rounded bg-neutral-100 transition-colors hover:bg-neutral-200"
       aria-label={expanded ? "Collapse chat" : "Expand chat"}
     >
       <svg
@@ -171,10 +178,10 @@
   <div
     bind:this={listEl}
     onscroll={onListScroll}
-    class="flex-1 overflow-y-auto flex flex-col -mr-6 pr-6"
+    class="-mr-6 flex flex-1 flex-col overflow-y-auto pr-6"
   >
     {#if messages.length === 0}
-      <div class="m-auto text-center text-sm text-neutral-400 py-8">
+      <div class="m-auto py-8 text-center text-sm text-neutral-400">
         No messages yet.
       </div>
     {:else}
@@ -184,7 +191,7 @@
           {@const parent = msg.replyToId ? getChatMessage(msg.replyToId) : null}
           {@const parentAuthor = parent ? resolveAuthor(parent.pubkey) : null}
           <div>
-            <div class="flex items-center gap-2 mb-1">
+            <div class="mb-1 flex items-center gap-2">
               {#if author.picture}
                 <img
                   src={author.picture}
@@ -193,7 +200,7 @@
                 />
               {:else}
                 <span
-                  class="h-6 w-6 shrink-0 rounded-full bg-neutral-200 flex items-center justify-center text-xs font-semibold text-neutral-500"
+                  class="flex h-6 w-6 shrink-0 items-center justify-center rounded-full bg-neutral-200 text-xs font-semibold text-neutral-500"
                 >
                   {author.name[0].toUpperCase()}
                 </span>
@@ -216,10 +223,8 @@
                   {/if}
                 </div>
               {/if}
-              <p
-                class="text-neutral-700 leading-5 whitespace-pre-wrap break-words"
-              >
-                {msg.content}
+              <p class="leading-5 text-neutral-700">
+                <ChatContent content={msg.content} {profiles} />
               </p>
               <div class="mt-0.5 flex items-center gap-2">
                 <div class="relative ml-auto">
@@ -228,7 +233,7 @@
                       e.stopPropagation();
                       openMenuId = openMenuId === msg.id ? null : msg.id;
                     }}
-                    class="flex items-center justify-center rounded p-0.5 text-neutral-300 hover:text-neutral-500 hover:bg-neutral-100 transition-colors"
+                    class="flex items-center justify-center rounded p-0.5 text-neutral-300 transition-colors hover:bg-neutral-100 hover:text-neutral-500"
                     aria-label="Message actions"
                   >
                     <svg
@@ -244,7 +249,7 @@
                   </button>
                   {#if openMenuId === msg.id}
                     <div
-                      class="absolute right-0 bottom-6 z-20 w-36 rounded-lg border border-neutral-100 bg-white py-1 shadow-lg text-sm"
+                      class="absolute right-0 bottom-6 z-20 w-36 rounded-lg border border-neutral-100 bg-white py-1 text-sm shadow-lg"
                     >
                       <button
                         onclick={(e) => {
@@ -271,7 +276,7 @@
       <div
         class="mb-2 flex items-start gap-2 rounded bg-neutral-50 px-2 py-1.5 text-xs text-neutral-600"
       >
-        <div class="flex-1 min-w-0">
+        <div class="min-w-0 flex-1">
           <span class="text-neutral-400">↳ Reply to </span>
           <span class="font-medium">{replyAuthor.name}</span>:
           <span class="text-neutral-500"
@@ -289,19 +294,20 @@
     {/if}
     {#if sendError}
       <div
-        class="mb-2 rounded bg-red-50 px-2 py-1.5 text-xs text-red-700 border border-red-200"
+        class="mb-2 rounded border border-red-200 bg-red-50 px-2 py-1.5 text-xs text-red-700"
       >
         {sendError}
       </div>
     {/if}
-    <textarea
+    <MentionAutocomplete
       bind:this={inputEl}
       bind:value={inputValue}
       onkeydown={onKeydown}
-      rows="1"
+      rows={1}
       disabled={sending}
       placeholder={auth.user ? "Message..." : "Login to send messages"}
-      class="w-full resize-none rounded border border-neutral-200 px-3 py-2 text-sm focus:outline-none focus:ring-1 focus:ring-brand disabled:opacity-50"
-    ></textarea>
+      {contextPubkeys}
+      textareaClass="w-full resize-none rounded border border-neutral-200 px-3 py-2 text-sm focus:outline-none focus:ring-1 focus:ring-brand disabled:opacity-50"
+    />
   </div>
 </aside>
diff --git a/src/lib/components/MentionAutocomplete.svelte b/src/lib/components/MentionAutocomplete.svelte
new file mode 100644
index 0000000..ac9f3bd
--- /dev/null
+++ b/src/lib/components/MentionAutocomplete.svelte
@@ -0,0 +1,401 @@
+<script lang="ts">
+  import { tick } from "svelte";
+  import * as nip19 from "@nostr/tools/nip19";
+  import { loadRelayList } from "@nostr/gadgets/lists";
+  import {
+    profileStore,
+    searchLocalProfiles,
+    searchRemoteProfiles,
+    type ProfileEntry,
+  } from "$lib/profiles.svelte";
+
+  type Props = {
+    value: string;
+    disabled?: boolean;
+    rows?: number;
+    placeholder?: string;
+    contextPubkeys?: string[];
+    textareaClass?: string;
+    onkeydown?: (e: KeyboardEvent) => void;
+    onfocus?: () => void;
+    onblur?: () => void;
+  };
+
+  let {
+    value = $bindable(),
+    disabled = false,
+    rows = 4,
+    placeholder = "",
+    contextPubkeys = [],
+    textareaClass = "",
+    onkeydown,
+    onfocus,
+    onblur,
+  }: Props = $props();
+
+  let textareaEl = $state<HTMLTextAreaElement | null>(null);
+  let listboxEl = $state<HTMLDivElement | null>(null);
+
+  let mentionQuery = $state<string | null>(null);
+  let mentionStart = $state(0);
+  let mentionEnd = $state(0);
+  let mentionRemoteResults = $state<ProfileEntry[]>([]);
+  let mentionIndex = $state(0);
+  let userMovedCursor = $state(false);
+  let anchorAbove = $state(false);
+  let remoteSearching = $state(false);
+  let remoteSearchTimer: ReturnType<typeof setTimeout> | null = null;
+  let remoteSearchAbort: AbortController | null = null;
+
+  const contextSet = $derived(new Set(contextPubkeys));
+
+  const mentionLocalResults = $derived.by(() => {
+    if (mentionQuery === null) return [];
+    if (mentionQuery === "") {
+      const out: ProfileEntry[] = [];
+      for (const pk of contextSet) {
+        const p = profileStore.profiles.get(pk);
+        if (p) out.push(p);
+      }
+      return out
+        .sort((a, b) =>
+          (a.name ?? a.displayName ?? "").localeCompare(
+            b.name ?? b.displayName ?? "",
+          ),
+        )
+        .slice(0, 8);
+    }
+    return searchLocalProfiles(mentionQuery, {
+      contextPubkeys: contextSet,
+      limit: 8,
+    });
+  });
+
+  // Most-relevant first internally, reversed for display so the best match
+  // sits at the bottom (closest to the textarea when the dropdown opens above).
+  const mergedResults = $derived.by(() => {
+    const seen = new Set<string>();
+    const out: ProfileEntry[] = [];
+    for (const p of mentionLocalResults) {
+      if (seen.has(p.pubkey)) continue;
+      seen.add(p.pubkey);
+      out.push(p);
+    }
+    for (const p of mentionRemoteResults) {
+      if (seen.has(p.pubkey)) continue;
+      seen.add(p.pubkey);
+      out.push(p);
+    }
+    return out.slice(0, 8).reverse();
+  });
+
+  const mentionOpen = $derived(mentionQuery !== null);
+
+  const safeMentionIndex = $derived.by(() => {
+    if (mergedResults.length === 0) return 0;
+    if (!userMovedCursor) return mergedResults.length - 1;
+    return Math.min(mentionIndex, mergedResults.length - 1);
+  });
+
+  export function focus(opts: { caretAtEnd?: boolean } = {}) {
+    const ta = textareaEl;
+    if (!ta) return;
+    ta.focus();
+    if (opts.caretAtEnd) {
+      const pos = ta.value.length;
+      ta.setSelectionRange(pos, pos);
+    }
+  }
+
+  export function getTextarea(): HTMLTextAreaElement | null {
+    return textareaEl;
+  }
+
+  // Warm the kind:10002 cache for thread participants so relay hints are
+  // ready by publish time. Best-effort, dedup across focus events.
+  const prefetched = new Set<string>();
+  function onTextareaFocus() {
+    for (const pk of contextPubkeys) {
+      if (prefetched.has(pk)) continue;
+      prefetched.add(pk);
+      loadRelayList(pk).catch(() => {});
+    }
+    onfocus?.();
+  }
+
+  function detectMentionContext(text: string, cursor: number) {
+    const before = text.slice(0, cursor);
+    const m = before.match(/(?:^|\s)@([^\s@]*)$/);
+    if (!m) return null;
+    const query = m[1];
+    return {
+      query,
+      start: cursor - query.length - 1,
+      end: cursor,
+    };
+  }
+
+  function scheduleRemoteSearch(query: string, localCount: number) {
+    if (remoteSearchTimer) clearTimeout(remoteSearchTimer);
+    remoteSearchAbort?.abort();
+    if (!query || query.length < 1 || localCount >= 8) {
+      mentionRemoteResults = [];
+      remoteSearching = false;
+      return;
+    }
+    remoteSearching = true;
+    remoteSearchTimer = setTimeout(async () => {
+      const abort = new AbortController();
+      remoteSearchAbort = abort;
+      const captured = query;
+      try {
+        const results = await searchRemoteProfiles(captured, abort.signal);
+        if (abort.signal.aborted) return;
+        if (mentionQuery !== captured) return;
+        mentionRemoteResults = results;
+      } finally {
+        if (mentionQuery === captured) remoteSearching = false;
+      }
+    }, 200);
+  }
+
+  function closeMention() {
+    mentionQuery = null;
+    mentionRemoteResults = [];
+    mentionIndex = 0;
+    userMovedCursor = false;
+    remoteSearching = false;
+    if (remoteSearchTimer) clearTimeout(remoteSearchTimer);
+    remoteSearchAbort?.abort();
+  }
+
+  function updateMentionFromTextarea() {
+    const ta = textareaEl;
+    if (!ta) {
+      closeMention();
+      return;
+    }
+    const ctx = detectMentionContext(ta.value, ta.selectionStart);
+    if (!ctx) {
+      closeMention();
+      return;
+    }
+    const wasOpen = mentionQuery !== null;
+    if (ctx.query !== mentionQuery) {
+      mentionIndex = 0;
+      userMovedCursor = false;
+      mentionRemoteResults = [];
+    }
+    mentionQuery = ctx.query;
+    mentionStart = ctx.start;
+    mentionEnd = ctx.end;
+    scheduleRemoteSearch(ctx.query, mentionLocalResults.length);
+    if (!wasOpen) updateAnchor();
+  }
+
+  function updateAnchor() {
+    const ta = textareaEl;
+    if (!ta) return;
+    const rect = ta.getBoundingClientRect();
+    const spaceBelow = window.innerHeight - rect.bottom;
+    const spaceAbove = rect.top;
+    anchorAbove = spaceBelow < 280 && spaceAbove > spaceBelow;
+  }
+
+  async function selectMention(entry: ProfileEntry) {
+    const ta = textareaEl;
+    if (!ta || mentionQuery === null) return;
+    const before = value.slice(0, mentionStart);
+    const after = value.slice(mentionEnd);
+
+    let relays: string[] = [];
+    try {
+      const list = await loadRelayList(entry.pubkey);
+      relays = list.items
+        .filter((r) => r.write)
+        .slice(0, 2)
+        .map((r) => r.url);
+    } catch {
+      // No hints — still a valid nprofile, just less robust for receivers.
+    }
+
+    const nprofile = nip19.nprofileEncode({ pubkey: entry.pubkey, relays });
+    const insertion = `nostr:${nprofile}`;
+    const trailing = after.startsWith(" ") ? "" : " ";
+    value = before + insertion + trailing + after;
+    closeMention();
+    await tick();
+    const pos = (before + insertion + trailing).length;
+    ta.focus();
+    ta.setSelectionRange(pos, pos);
+  }
+
+  function profileLabel(p: ProfileEntry): string {
+    return p.name || p.displayName || p.nip05 || p.npub.slice(0, 12) + "…";
+  }
+
+  function profileSubLabel(p: ProfileEntry): string | null {
+    const main = profileLabel(p);
+    if (p.nip05 && p.nip05 !== main) return p.nip05;
+    if (p.displayName && p.displayName !== main) return p.displayName;
+    return null;
+  }
+
+  function onTextareaInput() {
+    updateMentionFromTextarea();
+  }
+
+  function onTextareaKeydown(e: KeyboardEvent) {
+    if (mentionQuery !== null) {
+      if (e.key === "Escape") {
+        e.preventDefault();
+        closeMention();
+        return;
+      }
+      if (mergedResults.length > 0) {
+        if (e.key === "ArrowDown") {
+          e.preventDefault();
+          userMovedCursor = true;
+          mentionIndex = (safeMentionIndex + 1) % mergedResults.length;
+          return;
+        } else if (e.key === "ArrowUp") {
+          e.preventDefault();
+          userMovedCursor = true;
+          mentionIndex =
+            (safeMentionIndex - 1 + mergedResults.length) %
+            mergedResults.length;
+          return;
+        } else if (e.key === "Enter" || e.key === "Tab") {
+          e.preventDefault();
+          const entry = mergedResults[safeMentionIndex];
+          if (entry) selectMention(entry);
+          return;
+        }
+      }
+    }
+    onkeydown?.(e);
+  }
+
+  function onTextareaClickOrSelect() {
+    updateMentionFromTextarea();
+  }
+
+  function onTextareaBlur() {
+    setTimeout(() => closeMention(), 120);
+    onblur?.();
+  }
+
+  // Keep the highlighted (most-relevant) item visible as results change.
+  $effect(() => {
+    if (!listboxEl) return;
+    const idx = safeMentionIndex;
+    const items = listboxEl.querySelectorAll<HTMLElement>('[role="option"]');
+    items[idx]?.scrollIntoView({ block: "nearest" });
+  });
+</script>
+
+<div class="relative">
+  <textarea
+    bind:this={textareaEl}
+    bind:value
+    {disabled}
+    {rows}
+    {placeholder}
+    oninput={onTextareaInput}
+    onkeydown={onTextareaKeydown}
+    onclick={onTextareaClickOrSelect}
+    onkeyup={onTextareaClickOrSelect}
+    onfocus={onTextareaFocus}
+    onblur={onTextareaBlur}
+    aria-autocomplete="list"
+    aria-controls={mentionOpen ? "mention-listbox" : undefined}
+    class={textareaClass}
+  ></textarea>
+  {#if mentionOpen}
+    <div
+      id="mention-listbox"
+      bind:this={listboxEl}
+      class="absolute right-0 left-0 z-30 max-h-72 overflow-auto rounded border border-neutral-200 bg-white shadow-lg"
+      class:bottom-full={anchorAbove}
+      class:mb-1={anchorAbove}
+      class:top-full={!anchorAbove}
+      class:mt-1={!anchorAbove}
+    >
+      {#if mentionQuery === ""}
+        <div
+          class="px-3 py-1.5 text-xs text-neutral-400"
+          class:border-b={mergedResults.length > 0}
+          class:border-neutral-100={mergedResults.length > 0}
+        >
+          Type to search
+        </div>
+      {:else if remoteSearching && mergedResults.length > 0}
+        <div
+          class="flex items-center gap-2 border-b border-neutral-100 px-3 py-1.5 text-xs text-neutral-400"
+          aria-live="polite"
+        >
+          <span
+            class="inline-block h-3 w-3 animate-spin rounded-full border border-neutral-300 border-t-neutral-600"
+            aria-hidden="true"
+          ></span>
+          <span>Searching…</span>
+        </div>
+      {/if}
+      {#if mergedResults.length === 0 && mentionQuery !== ""}
+        <div class="flex items-center gap-2 px-3 py-2 text-xs text-neutral-400">
+          {#if remoteSearching}
+            <span
+              class="inline-block h-3 w-3 animate-spin rounded-full border border-neutral-300 border-t-neutral-600"
+              aria-hidden="true"
+            ></span>
+            <span>Searching…</span>
+          {:else}
+            No matches
+          {/if}
+        </div>
+      {:else if mergedResults.length > 0}
+        <ul role="listbox">
+          {#each mergedResults as entry, i (entry.pubkey)}
+            <li
+              role="option"
+              aria-selected={i === safeMentionIndex}
+              class="flex cursor-pointer items-center gap-2 px-3 py-1.5 text-sm"
+              class:bg-neutral-100={i === safeMentionIndex}
+              onmousedown={(e) => {
+                e.preventDefault();
+                selectMention(entry);
+              }}
+              onmouseenter={() => {
+                userMovedCursor = true;
+                mentionIndex = i;
+              }}
+            >
+              {#if entry.picture}
+                <img
+                  src={entry.picture}
+                  alt=""
+                  class="h-6 w-6 flex-shrink-0 rounded-full object-cover"
+                />
+              {:else}
+                <span
+                  class="flex h-6 w-6 flex-shrink-0 items-center justify-center rounded-full bg-neutral-200 text-xs text-neutral-500"
+                  aria-hidden="true"
+                >
+                  {profileLabel(entry)[0]?.toUpperCase() ?? "?"}
+                </span>
+              {/if}
+              <span class="truncate font-medium text-neutral-700">
+                {profileLabel(entry)}
+              </span>
+              {#if profileSubLabel(entry)}
+                <span class="truncate text-xs text-neutral-400">
+                  {profileSubLabel(entry)}
+                </span>
+              {/if}
+            </li>
+          {/each}
+        </ul>
+      {/if}
+    </div>
+  {/if}
+</div>
diff --git a/src/lib/components/MessageEditor.svelte b/src/lib/components/MessageEditor.svelte
index fb304e5..85db2be 100644
--- a/src/lib/components/MessageEditor.svelte
+++ b/src/lib/components/MessageEditor.svelte
@@ -1,16 +1,9 @@
 <script lang="ts">
   import { tick } from "svelte";
-  import * as nip19 from "@nostr/tools/nip19";
-  import { loadRelayList } from "@nostr/gadgets/lists";
   import { uploadImage } from "$lib/blossom";
   import { BLOSSOM_URL } from "$lib/config";
   import PostContent from "$lib/components/PostContent.svelte";
-  import {
-    profileStore,
-    searchLocalProfiles,
-    searchRemoteProfiles,
-    type ProfileEntry,
-  } from "$lib/profiles.svelte";
+  import MentionAutocomplete from "$lib/components/MentionAutocomplete.svelte";
 
   type Props = {
     value: string;
@@ -34,94 +27,13 @@
     threadEventAuthors = {},
   }: Props = $props();
 
-  let textareaEl = $state<HTMLTextAreaElement | null>(null);
+  let editorEl = $state<MentionAutocomplete | null>(null);
   let fileInputEl = $state<HTMLInputElement | null>(null);
   let uploadError = $state<string | null>(null);
   let previewing = $state(false);
 
-  // Mention autocomplete state
-  let mentionQuery = $state<string | null>(null);
-  let mentionStart = $state(0);
-  let mentionEnd = $state(0);
-  let mentionRemoteResults = $state<ProfileEntry[]>([]);
-  let mentionIndex = $state(0);
-  let userMovedCursor = $state(false);
-  let anchorAbove = $state(false);
-  let remoteSearching = $state(false);
-  let remoteSearchTimer: ReturnType<typeof setTimeout> | null = null;
-  let remoteSearchAbort: AbortController | null = null;
-  let listboxEl = $state<HTMLDivElement | null>(null);
-
-  const contextSet = $derived(new Set(contextPubkeys));
-
-  const mentionLocalResults = $derived.by(() => {
-    if (mentionQuery === null) return [];
-    if (mentionQuery === "") {
-      // Bare "@": only thread participants we know about, no global cache spill.
-      const out: ProfileEntry[] = [];
-      for (const pk of contextSet) {
-        const p = profileStore.profiles.get(pk);
-        if (p) out.push(p);
-      }
-      return out
-        .sort((a, b) =>
-          (a.name ?? a.displayName ?? "").localeCompare(
-            b.name ?? b.displayName ?? "",
-          ),
-        )
-        .slice(0, 8);
-    }
-    return searchLocalProfiles(mentionQuery, {
-      contextPubkeys: contextSet,
-      limit: 8,
-    });
-  });
-
-  // Most-relevant first internally, reversed for display so the best match
-  // sits at the bottom (closest to the textarea when the dropdown opens above).
-  const mergedResults = $derived.by(() => {
-    const seen = new Set<string>();
-    const out: ProfileEntry[] = [];
-    for (const p of mentionLocalResults) {
-      if (seen.has(p.pubkey)) continue;
-      seen.add(p.pubkey);
-      out.push(p);
-    }
-    for (const p of mentionRemoteResults) {
-      if (seen.has(p.pubkey)) continue;
-      seen.add(p.pubkey);
-      out.push(p);
-    }
-    return out.slice(0, 8).reverse();
-  });
-
-  const mentionOpen = $derived(mentionQuery !== null);
-
-  const safeMentionIndex = $derived.by(() => {
-    if (mergedResults.length === 0) return 0;
-    if (!userMovedCursor) return mergedResults.length - 1;
-    return Math.min(mentionIndex, mergedResults.length - 1);
-  });
-
   export function focus(opts: { caretAtEnd?: boolean } = {}) {
-    const ta = textareaEl;
-    if (!ta) return;
-    ta.focus();
-    if (opts.caretAtEnd) {
-      const pos = ta.value.length;
-      ta.setSelectionRange(pos, pos);
-    }
-  }
-
-  // Warm the kind:10002 cache for thread participants so relay hints are
-  // ready by publish time. Best-effort, dedup across focus events.
-  const prefetched = new Set<string>();
-  function onTextareaFocus() {
-    for (const pk of contextPubkeys) {
-      if (prefetched.has(pk)) continue;
-      prefetched.add(pk);
-      loadRelayList(pk).catch(() => {});
-    }
+    editorEl?.focus(opts);
   }
 
   function togglePreview() {
@@ -140,7 +52,7 @@
     uploading = true;
     try {
       const blob = await uploadImage(file);
-      const ta = textareaEl;
+      const ta = editorEl?.getTextarea();
       if (ta) {
         const start = ta.selectionStart;
         const end = ta.selectionEnd;
@@ -163,176 +75,12 @@
       input.value = "";
     }
   }
-
-  function detectMentionContext(text: string, cursor: number) {
-    const before = text.slice(0, cursor);
-    const m = before.match(/(?:^|\s)@([^\s@]*)$/);
-    if (!m) return null;
-    const query = m[1];
-    return {
-      query,
-      start: cursor - query.length - 1,
-      end: cursor,
-    };
-  }
-
-  function scheduleRemoteSearch(query: string, localCount: number) {
-    if (remoteSearchTimer) clearTimeout(remoteSearchTimer);
-    remoteSearchAbort?.abort();
-    if (!query || query.length < 1 || localCount >= 8) {
-      mentionRemoteResults = [];
-      remoteSearching = false;
-      return;
-    }
-    remoteSearching = true;
-    remoteSearchTimer = setTimeout(async () => {
-      const abort = new AbortController();
-      remoteSearchAbort = abort;
-      const captured = query;
-      try {
-        const results = await searchRemoteProfiles(captured, abort.signal);
-        if (abort.signal.aborted) return;
-        if (mentionQuery !== captured) return;
-        mentionRemoteResults = results;
-      } finally {
-        if (mentionQuery === captured) remoteSearching = false;
-      }
-    }, 200);
-  }
-
-  function closeMention() {
-    mentionQuery = null;
-    mentionRemoteResults = [];
-    mentionIndex = 0;
-    userMovedCursor = false;
-    remoteSearching = false;
-    if (remoteSearchTimer) clearTimeout(remoteSearchTimer);
-    remoteSearchAbort?.abort();
-  }
-
-  function updateMentionFromTextarea() {
-    const ta = textareaEl;
-    if (!ta) {
-      closeMention();
-      return;
-    }
-    const ctx = detectMentionContext(ta.value, ta.selectionStart);
-    if (!ctx) {
-      closeMention();
-      return;
-    }
-    const wasOpen = mentionQuery !== null;
-    if (ctx.query !== mentionQuery) {
-      mentionIndex = 0;
-      userMovedCursor = false;
-      mentionRemoteResults = [];
-    }
-    mentionQuery = ctx.query;
-    mentionStart = ctx.start;
-    mentionEnd = ctx.end;
-    scheduleRemoteSearch(ctx.query, mentionLocalResults.length);
-    if (!wasOpen) updateAnchor();
-  }
-
-  function updateAnchor() {
-    const ta = textareaEl;
-    if (!ta) return;
-    const rect = ta.getBoundingClientRect();
-    const spaceBelow = window.innerHeight - rect.bottom;
-    const spaceAbove = rect.top;
-    anchorAbove = spaceBelow < 280 && spaceAbove > spaceBelow;
-  }
-
-  async function selectMention(entry: ProfileEntry) {
-    const ta = textareaEl;
-    if (!ta || mentionQuery === null) return;
-    const before = value.slice(0, mentionStart);
-    const after = value.slice(mentionEnd);
-
-    // Fetch the user's kind:10002 to embed write-relay hints in the nprofile.
-    // Cached by gadgets, so repeat selections are instant.
-    let relays: string[] = [];
-    try {
-      const list = await loadRelayList(entry.pubkey);
-      relays = list.items
-        .filter((r) => r.write)
-        .slice(0, 2)
-        .map((r) => r.url);
-    } catch {
-      // No hints — still a valid nprofile, just less robust for receivers.
-    }
-
-    const nprofile = nip19.nprofileEncode({ pubkey: entry.pubkey, relays });
-    const insertion = `nostr:${nprofile}`;
-    const trailing = after.startsWith(" ") ? "" : " ";
-    value = before + insertion + trailing + after;
-    closeMention();
-    await tick();
-    const pos = (before + insertion + trailing).length;
-    ta.focus();
-    ta.setSelectionRange(pos, pos);
-  }
-
-  function profileLabel(p: ProfileEntry): string {
-    return p.name || p.displayName || p.nip05 || p.npub.slice(0, 12) + "…";
-  }
-
-  function profileSubLabel(p: ProfileEntry): string | null {
-    const main = profileLabel(p);
-    if (p.nip05 && p.nip05 !== main) return p.nip05;
-    if (p.displayName && p.displayName !== main) return p.displayName;
-    return null;
-  }
-
-  function onTextareaInput() {
-    updateMentionFromTextarea();
-  }
-
-  function onTextareaKeydown(e: KeyboardEvent) {
-    if (mentionQuery === null) return;
-    if (e.key === "Escape") {
-      e.preventDefault();
-      closeMention();
-      return;
-    }
-    if (mergedResults.length === 0) return;
-    if (e.key === "ArrowDown") {
-      e.preventDefault();
-      userMovedCursor = true;
-      mentionIndex = (safeMentionIndex + 1) % mergedResults.length;
-    } else if (e.key === "ArrowUp") {
-      e.preventDefault();
-      userMovedCursor = true;
-      mentionIndex =
-        (safeMentionIndex - 1 + mergedResults.length) % mergedResults.length;
-    } else if (e.key === "Enter" || e.key === "Tab") {
-      e.preventDefault();
-      const entry = mergedResults[safeMentionIndex];
-      if (entry) selectMention(entry);
-    }
-  }
-
-  function onTextareaClickOrSelect() {
-    updateMentionFromTextarea();
-  }
-
-  function onTextareaBlur() {
-    setTimeout(() => closeMention(), 120);
-  }
-
-  // Keep the highlighted (most-relevant) item visible as results change.
-  $effect(() => {
-    if (!listboxEl) return;
-    const idx = safeMentionIndex;
-    const items = listboxEl.querySelectorAll<HTMLElement>('[role="option"]');
-    items[idx]?.scrollIntoView({ block: "nearest" });
-  });
 </script>
 
-<div class="flex flex-col {previewing ? 'flex-1 min-h-0' : ''}">
+<div class="flex flex-col {previewing ? 'min-h-0 flex-1' : ''}">
   {#if previewing}
     <div
-      class="w-full rounded-t border border-neutral-200 px-3 py-2 overflow-auto flex-1 min-h-0 max-h-[70vh] {minHeightClass}"
+      class="max-h-[70vh] min-h-0 w-full flex-1 overflow-auto rounded-t border border-neutral-200 px-3 py-2 {minHeightClass}"
       aria-label="Preview"
     >
       {#if value.trim()}
@@ -342,113 +90,15 @@
       {/if}
     </div>
   {:else}
-    <div class="relative">
-      <textarea
-        bind:this={textareaEl}
-        bind:value
-        {disabled}
-        {rows}
-        {placeholder}
-        oninput={onTextareaInput}
-        onkeydown={onTextareaKeydown}
-        onclick={onTextareaClickOrSelect}
-        onkeyup={onTextareaClickOrSelect}
-        onfocus={onTextareaFocus}
-        onblur={onTextareaBlur}
-        aria-autocomplete="list"
-        aria-controls={mentionOpen ? "mention-listbox" : undefined}
-        class="block w-full rounded-t border border-neutral-200 px-3 py-2 focus:outline-none focus:ring-1 focus:ring-brand disabled:opacity-50 resize-y {minHeightClass}"
-      ></textarea>
-      {#if mentionOpen}
-        <div
-          id="mention-listbox"
-          bind:this={listboxEl}
-          class="absolute z-30 left-0 right-0 max-h-72 overflow-auto rounded border border-neutral-200 bg-white shadow-lg"
-          class:bottom-full={anchorAbove}
-          class:mb-1={anchorAbove}
-          class:top-full={!anchorAbove}
-          class:mt-1={!anchorAbove}
-        >
-          {#if mentionQuery === ""}
-            <div
-              class="px-3 py-1.5 text-xs text-neutral-400"
-              class:border-b={mergedResults.length > 0}
-              class:border-neutral-100={mergedResults.length > 0}
-            >
-              Type to search
-            </div>
-          {:else if remoteSearching && mergedResults.length > 0}
-            <div
-              class="px-3 py-1.5 text-xs text-neutral-400 flex items-center gap-2 border-b border-neutral-100"
-              aria-live="polite"
-            >
-              <span
-                class="h-3 w-3 inline-block rounded-full border border-neutral-300 border-t-neutral-600 animate-spin"
-                aria-hidden="true"
-              ></span>
-              <span>Searching…</span>
-            </div>
-          {/if}
-          {#if mergedResults.length === 0 && mentionQuery !== ""}
-            <div
-              class="px-3 py-2 text-xs text-neutral-400 flex items-center gap-2"
-            >
-              {#if remoteSearching}
-                <span
-                  class="h-3 w-3 inline-block rounded-full border border-neutral-300 border-t-neutral-600 animate-spin"
-                  aria-hidden="true"
-                ></span>
-                <span>Searching…</span>
-              {:else}
-                No matches
-              {/if}
-            </div>
-          {:else if mergedResults.length > 0}
-            <ul role="listbox">
-              {#each mergedResults as entry, i (entry.pubkey)}
-                <li
-                  role="option"
-                  aria-selected={i === safeMentionIndex}
-                  class="flex items-center gap-2 px-3 py-1.5 cursor-pointer text-sm"
-                  class:bg-neutral-100={i === safeMentionIndex}
-                  onmousedown={(e) => {
-                    e.preventDefault();
-                    selectMention(entry);
-                  }}
-                  onmouseenter={() => {
-                    userMovedCursor = true;
-                    mentionIndex = i;
-                  }}
-                >
-                  {#if entry.picture}
-                    <img
-                      src={entry.picture}
-                      alt=""
-                      class="h-6 w-6 rounded-full object-cover flex-shrink-0"
-                    />
-                  {:else}
-                    <span
-                      class="h-6 w-6 rounded-full bg-neutral-200 flex items-center justify-center text-xs text-neutral-500 flex-shrink-0"
-                      aria-hidden="true"
-                    >
-                      {profileLabel(entry)[0]?.toUpperCase() ?? "?"}
-                    </span>
-                  {/if}
-                  <span class="font-medium text-neutral-700 truncate">
-                    {profileLabel(entry)}
-                  </span>
-                  {#if profileSubLabel(entry)}
-                    <span class="text-xs text-neutral-400 truncate">
-                      {profileSubLabel(entry)}
-                    </span>
-                  {/if}
-                </li>
-              {/each}
-            </ul>
-          {/if}
-        </div>
-      {/if}
-    </div>
+    <MentionAutocomplete
+      bind:this={editorEl}
+      bind:value
+      {disabled}
+      {rows}
+      {placeholder}
+      {contextPubkeys}
+      textareaClass="block w-full rounded-t border border-neutral-200 px-3 py-2 focus:outline-none focus:ring-1 focus:ring-brand disabled:opacity-50 resize-y {minHeightClass}"
+    />
   {/if}
   <div
     class="flex flex-shrink-0 items-center gap-4 rounded-b border border-t-0 border-neutral-200 bg-neutral-50 px-3 py-2 text-sm"
@@ -458,7 +108,7 @@
       onclick={onUploadClick}
       disabled={uploading || disabled || previewing || !BLOSSOM_URL}
       title={!BLOSSOM_URL ? "Blossom server not configured" : ""}
-      class="inline-flex items-center gap-1.5 text-neutral-600 hover:text-neutral-900 disabled:opacity-50 disabled:cursor-not-allowed"
+      class="inline-flex items-center gap-1.5 text-neutral-600 hover:text-neutral-900 disabled:cursor-not-allowed disabled:opacity-50"
     >
       <svg
         width="16"
@@ -485,7 +135,7 @@
       onclick={togglePreview}
       disabled={disabled || uploading}
       aria-pressed={previewing}
-      class="ml-auto inline-flex items-center gap-1.5 text-neutral-600 hover:text-neutral-900 disabled:opacity-50 disabled:cursor-not-allowed"
+      class="ml-auto inline-flex items-center gap-1.5 text-neutral-600 hover:text-neutral-900 disabled:cursor-not-allowed disabled:opacity-50"
     >
       <svg
         width="16"