Index: src/routes/posts.js
===================================================================
--- src/routes/posts.js	(revision 5190152c90d2d397b7f87f9c900eae8d8c1e2856)
+++ src/routes/posts.js	(revision e9c9ae1db68ca932789d82108c91af5e8bab1058)
@@ -761,8 +761,10 @@
   let attachments = [];
   try { attachments = JSON.parse(req.body.attachments || '[]'); } catch { /* geen media */ }
+  let mentions;   // undefined = geen balk meegestuurd (legacy addressing)
+  try { if (req.body.mentions !== undefined) mentions = JSON.parse(req.body.mentions || '[]'); } catch { mentions = undefined; }
   if (site && uri && (text.trim() || html.trim() || (Array.isArray(attachments) && attachments.length))) {
     // Resolve + deliver in the background so Send responds instantly.
     ActivityPubService.resolveRemoteNote(uri)
-      .then((parent) => parent && ActivityPubService.deliverReply(site, { postId: parent.localPostId || '', postSlug: null, parent, text, html, language, attachments }))
+      .then((parent) => parent && ActivityPubService.deliverReply(site, { postId: parent.localPostId || '', postSlug: null, parent, text, html, language, attachments, mentions }))
       .catch((e) => console.warn('[AP] remote reply failed:', e.message));
   }
@@ -1314,8 +1316,10 @@
   let attachments = [];
   try { attachments = JSON.parse(req.body.attachments || '[]'); } catch { /* geen media */ }
+  let mentions;   // undefined = geen balk meegestuurd (legacy addressing)
+  try { if (req.body.mentions !== undefined) mentions = JSON.parse(req.body.mentions || '[]'); } catch { mentions = undefined; }
   if (parent && parent.post_id === post.id && (text.trim() || html.trim() || (Array.isArray(attachments) && attachments.length))) {
     try {
       await ActivityPubService.deliverReply(site, {
-        postId: post.id, postSlug: post.slug, parent, text, html, attachments,
+        postId: post.id, postSlug: post.slug, parent, text, html, attachments, mentions,
         language: (req.body.language || '').toString(),
       });