Index: test/inbound-mentions.test.js
===================================================================
--- test/inbound-mentions.test.js	(revision fe97cc38d423c6b67d75cc07bab36c9ef2dd4f91)
+++ test/inbound-mentions.test.js	(revision fe97cc38d423c6b67d75cc07bab36c9ef2dd4f91)
@@ -0,0 +1,49 @@
+// Inbound mentions — a remote note whose Mention tag targets one of our actors becomes a
+// notification, even when it isn't a reply to our content. localMentionSlugs is the detection
+// core: only OUR base counts, the slug must exist, deduped. In-memory SQLite. Run: npm test
+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');
+const db = dbMod.default;
+dbMod.initializeDatabase();
+const AP = (await import('../src/services/ActivityPubService.js')).default;
+
+const BASE = 'https://test.example';
+db.prepare('INSERT INTO users (id, username, email, password_hash, role) VALUES (?,?,?,?,?)').run('u1', 'u1', 'u1@test', 'x', 'god');
+db.prepare('INSERT INTO sites (id, slug, title, owner_id, is_primary) VALUES (?,?,?,?,?)').run('s1', 'demo', 'Demo', 'u1', 1);
+
+test('a Mention tag with our actor href resolves to the site slug', () => {
+  const tags = [
+    { type: 'Mention', href: `${BASE}/ap/users/demo`, name: '@demo@test.example' },
+    { type: 'Hashtag', href: `${BASE}/tag/x`, name: '#x' },
+  ];
+  assert.deepEqual(AP.localMentionSlugs(tags, BASE), ['demo']);
+});
+
+test('a remote host with the same /ap/users path is NOT ours', () => {
+  const tags = [{ type: 'Mention', href: 'https://other.example/ap/users/demo', name: '@demo@other.example' }];
+  assert.deepEqual(AP.localMentionSlugs(tags, BASE), []);
+});
+
+test('a mention of a non-existent slug is ignored; duplicates dedupe', () => {
+  const tags = [
+    { type: 'Mention', href: `${BASE}/ap/users/ghost`, name: '@ghost' },
+    { type: 'Mention', href: `${BASE}/ap/users/demo`, name: '@demo' },
+    { type: 'Mention', href: `${BASE}/ap/users/demo`, name: '@demo' },
+  ];
+  assert.deepEqual(AP.localMentionSlugs(tags, BASE), ['demo']);
+});
+
+test('a stored mention shows up in the notifications', () => {
+  db.prepare('INSERT OR IGNORE INTO ap_mentions (slug, object_uri, note_url, actor_uri, actor_name, actor_handle, content) VALUES (?,?,?,?,?,?,?)')
+    .run('demo', 'https://m.example/notes/1', 'https://m.example/@a/1', 'https://m.example/users/a', 'Anna', '@a@m.example', '<p>hi @demo</p>');
+  const items = AP.getNotifications('demo', 20);
+  const m = items.find((n) => n.type === 'mention');
+  assert.ok(m, 'mention notification present');
+  assert.equal(m.handle, '@a@m.example');
+  assert.equal(m.note_url, 'https://m.example/@a/1');
+});