diff --git a/apps.html b/apps.html
index ecc4486..7b2b775 100644
--- a/apps.html
+++ b/apps.html
@@ -1437,6 +1437,13 @@ <h3>Chaos - Stranger Missions</h3>
       const src = card.querySelector('img')?.getAttribute('src') || '';
       return src.split('/').pop()?.replace(/\.png$/, '') || '';
     };
+    // Keep the selected purpose shareable across reloads without exposing search text.
+    const syncGoalUrl = () => {
+      const url = new URL(window.location.href);
+      if (goal === 'all') url.searchParams.delete('goal');
+      else url.searchParams.set('goal', goal);
+      window.history.replaceState(window.history.state, '', url.pathname + url.search + url.hash);
+    };
     const fire = (event, data) => {
       if (typeof window.gtag === 'function') window.gtag('event', event, data);
     };
@@ -1476,6 +1483,7 @@ <h3>Chaos - Stranger Missions</h3>
       goal = 'all';
       lastReportedSearch = '';
       buttons.forEach(button => button.setAttribute('aria-pressed', String(button.dataset.goal === 'all')));
+      syncGoalUrl();
       render();
       input.focus();
       fire('catalog_search_reset', {source: 'empty_state'});
@@ -1483,6 +1491,7 @@ <h3>Chaos - Stranger Missions</h3>
     buttons.forEach(button => button.addEventListener('click', () => {
       goal = button.dataset.goal;
       buttons.forEach(b => b.setAttribute('aria-pressed', String(b === button)));
+      syncGoalUrl();
       fire('catalog_filter_used', {goal, results: render()});
     }));
     document.querySelectorAll('[data-detail-app]').forEach(link => {
diff --git a/scripts/test_guide_catalog_links.py b/scripts/test_guide_catalog_links.py
index b013a70..a8c9281 100644
--- a/scripts/test_guide_catalog_links.py
+++ b/scripts/test_guide_catalog_links.py
@@ -55,6 +55,23 @@ def test_missing_baseline_app_is_rejected(self):
         cards = '<a class="app-card"></a>' * (MIN_CATALOG_CARDS - 1)
         self.assertFalse(catalog_card_count_ok(cards))
 
+    def test_manual_filter_syncs_shareable_goal_url(self):
+        catalog = (ROOT / "apps.html").read_text(encoding="utf-8")
+        self.assertIn("const syncGoalUrl = () =>", catalog)
+        self.assertIn("url.searchParams.set('goal', goal)", catalog)
+        self.assertIn("url.searchParams.delete('goal')", catalog)
+        self.assertIn("window.history.replaceState(", catalog)
+        self.assertIn("url.pathname + url.search + url.hash", catalog)
+        self.assertEqual(catalog.count("      syncGoalUrl();"), 2)
+
+    def test_filter_url_does_not_capture_private_search_text(self):
+        catalog = (ROOT / "apps.html").read_text(encoding="utf-8")
+        start = catalog.index("const syncGoalUrl = () =>")
+        end = catalog.index("    const fire =", start)
+        sync_code = catalog[start:end]
+        self.assertNotIn("input.value", sync_code)
+        self.assertNotIn("find-app", sync_code)
+
     def test_catalog_cards_and_details_preserved(self):
         catalog = (ROOT / "apps.html").read_text(encoding="utf-8")
         self.assertTrue(catalog_card_count_ok(catalog), "app catalog fell below the 92-card baseline")