Index: src/config/database.js
===================================================================
--- src/config/database.js	(revision 0cea12bab4582ddc1462b7adef282a7c0afdcbcf)
+++ src/config/database.js	(revision 81b2e1ecaea6d206491e032514f0a2fdca4cb48a)
@@ -440,4 +440,5 @@
   // Rich replies: JSON array [{url, mediaType, name}] → `attachment` on the Note.
   ensureColumn('ap_outbox', 'attachments', 'TEXT');
+  ensureColumn('posts', 'ap_visibility', 'TEXT');   // public|quiet|friends|direct (C2S addressing, shaer-60b)
 }
 
Index: src/services/ActivityPubService.js
===================================================================
--- src/services/ActivityPubService.js	(revision 0cea12bab4582ddc1462b7adef282a7c0afdcbcf)
+++ src/services/ActivityPubService.js	(revision 81b2e1ecaea6d206491e032514f0a2fdca4cb48a)
@@ -429,8 +429,11 @@
     // fan_only = "fans only" → followers-only visibility (delivered to your followers
     // but not addressed to Public, so Mastodon shows it only to them and can't boost it).
-    to: post.fan_only ? [`${aId}/followers`] : [PUBLIC],
+    to: (post.fan_only || post.ap_visibility === 'quiet') ? [`${aId}/followers`] : [PUBLIC],
     // Mentioned actors (from inline @user@host links the caller resolved) are addressed in cc
     // so Mastodon notifies them; empty unless the content was mention-linked (delivery time).
-    cc: [...new Set([...(post.fan_only ? [] : [`${aId}/followers`]), ..._mentionCc])],
+    cc: [...new Set([
+      ...(post.ap_visibility === 'quiet' ? [PUBLIC] : []),          // quiet public: Public in cc, not to
+      ...((post.fan_only || post.ap_visibility === 'quiet') ? [] : [`${aId}/followers`]),
+      ..._mentionCc])],
     tag: [...buildHashtagList(base, post.tags, body), ..._mentionTags],
     replies: `${id}/replies`,
@@ -1887,12 +1890,35 @@
   const slug = 'n-' + postId.slice(0, 8);
   const now = new Date().toISOString();
-  db.prepare(`INSERT INTO posts (id, site_id, slug, author_id, title, content, excerpt, status, type, language, created_at, updated_at, published_at)
-              VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?)`)
-    .run(postId, site.id, slug, user.id, '', html, '', 'published', 'post', object.language || 'nl', now, now, now);
+  // Visibility from the note's addressing (shaer-60b): Public in `to` = loud
+  // public, Public in `cc` = quiet public (unlisted), followers-only = friends
+  // (rides the existing fan_only pipeline: followers-only AP delivery + web
+  // gating), neither = participants-only (kept local until mention addressing
+  // lands; still followers-gated on the web).
+  const vis = c2sVisibility(object);
+  const fanOnly = (vis === 'friends' || vis === 'direct') ? 1 : 0;
+  db.prepare(`INSERT INTO posts (id, site_id, slug, author_id, title, content, excerpt, status, type, language, fan_only, ap_visibility, created_at, updated_at, published_at)
+              VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)`)
+    .run(postId, site.id, slug, user.id, '', html, '', 'published', 'post', object.language || 'nl', fanOnly, vis, now, now, now);
   try { db.prepare('UPDATE posts SET content_rendered = ? WHERE id = ?').run(bakePostContent(html), postId); } catch { /* render fallback covers it */ }
   bakePostContentWithMentions(html).then((h) => { try { db.prepare('UPDATE posts SET content_rendered = ? WHERE id = ?').run(h, postId); } catch { /* keep sync bake */ } }).catch(() => {});
   try { db.prepare('INSERT INTO posts_fts(content, title, author, post_id) VALUES (?,?,?,?)').run(HtmlSanitizerService.toPlainText(html), '', user.username || '', postId); } catch { /* FTS non-fatal */ }
-  deliverCreate(site, { id: postId, slug, title: '', content: html, published_at: now, created_at: now }).catch(() => { /* best-effort */ });
+  if (vis !== 'direct') {
+    deliverCreate(site, { id: postId, slug, title: '', content: html, published_at: now, created_at: now, fan_only: fanOnly, ap_visibility: vis }).catch(() => { /* best-effort */ });
+  }
   return { status: 201, id: postId, url: `${base}/ap/notes/${postId}` };
+}
+
+// Addressing → visibility. Arrays or bare strings; unknown shapes read as the
+// safest bucket they match.
+export function c2sVisibility(object) {
+  const arr = (v) => (Array.isArray(v) ? v : (v ? [v] : [])).filter((x) => typeof x === 'string');
+  const to = arr(object.to), cc = arr(object.cc);
+  const isPublic = (x) => x === PUBLIC || x === 'as:Public' || x === 'Public';
+  const isFollowers = (x) => /\/followers\/?$/.test(x);
+  if (to.some(isPublic)) return 'public';
+  if (cc.some(isPublic)) return 'quiet';
+  if (to.some(isFollowers) || cc.some(isFollowers)) return 'friends';
+  if (!to.length && !cc.length) return 'public';   // no addressing at all: legacy client, keep old behavior
+  return 'direct';
 }
 
@@ -2904,4 +2930,4 @@
   linkifyBody, bakePostContent, bakePostContentWithMentions, listFollowers, removeFollower, listConnections,
   noteVisibility, isRejectedObject, rejectInteraction, interactionReportTarget,
-  getMessages, notificationsSeenAt, ingestOutboxActivity,
+  getMessages, notificationsSeenAt, ingestOutboxActivity, c2sVisibility,
 };
Index: test/c2s-visibility.test.js
===================================================================
--- test/c2s-visibility.test.js	(revision 81b2e1ecaea6d206491e032514f0a2fdca4cb48a)
+++ test/c2s-visibility.test.js	(revision 81b2e1ecaea6d206491e032514f0a2fdca4cb48a)
@@ -0,0 +1,40 @@
+// C2S visibility (shaer-60b): the note's to/cc addressing decides how a post
+// federates. friends/direct ride the fan_only pipeline; quiet puts Public in
+// cc (unlisted); no addressing keeps the legacy public behavior.
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+
+process.env.DATABASE_PATH = ':memory:';
+process.env.PUBLIC_BASE_URL = 'https://test.example';
+
+const dbMod = await import('../src/config/database.js');
+dbMod.initializeDatabase();
+const AP = (await import('../src/services/ActivityPubService.js')).default;
+
+const PUB = 'https://www.w3.org/ns/activitystreams#Public';
+const F = 'https://test.example/ap/users/me/followers';
+
+test('addressing maps to the right visibility bucket', () => {
+  assert.equal(AP.c2sVisibility({ to: [PUB] }), 'public');
+  assert.equal(AP.c2sVisibility({ to: [F], cc: [PUB] }), 'quiet');
+  assert.equal(AP.c2sVisibility({ to: [F] }), 'friends');
+  assert.equal(AP.c2sVisibility({ to: ['https://a.test/u/x'] }), 'direct');
+  assert.equal(AP.c2sVisibility({}), 'public');            // legacy client
+  assert.equal(AP.c2sVisibility({ to: PUB }), 'public');   // bare string form
+});
+
+test('a quiet post addresses followers in to and Public in cc', () => {
+  const site = { slug: 'me', primary_slug: 'me' };
+  const post = { id: 'p1', slug: 'x', title: '', content: '<p>hi</p>', tags: '[]', created_at: '2026-01-01T00:00:00Z', ap_visibility: 'quiet' };
+  const note = AP.buildNote('https://test.example', site, post);
+  assert.deepEqual(note.to, [F]);
+  assert.ok(note.cc.includes(PUB), 'Public rides in cc');
+});
+
+test('a friends (fan_only) post never addresses Public', () => {
+  const site = { slug: 'me', primary_slug: 'me' };
+  const post = { id: 'p2', slug: 'y', title: '', content: '<p>hi</p>', tags: '[]', created_at: '2026-01-01T00:00:00Z', fan_only: 1, ap_visibility: 'friends' };
+  const note = AP.buildNote('https://test.example', site, post);
+  assert.deepEqual(note.to, [F]);
+  assert.ok(!note.cc.includes(PUB));
+});