diff --git a/src/seedpass_gui/app.py b/src/seedpass_gui/app.py
index 88ea909..b3041f5 100644
--- a/src/seedpass_gui/app.py
+++ b/src/seedpass_gui/app.py
@@ -102,6 +102,7 @@ class MainWindow(toga.Window):
         search_button = toga.Button("Search", on_press=self.search_entries)
         relay_button = toga.Button("Relays", on_press=self.manage_relays)
         totp_button = toga.Button("TOTP", on_press=self.show_totp_codes)
+        sync_button = toga.Button("Sync", on_press=self.start_vault_sync)
 
         button_box = toga.Box(style=Pack(direction=ROW, padding_top=5))
         button_box.add(add_button)
@@ -109,6 +110,7 @@ class MainWindow(toga.Window):
         button_box.add(search_button)
         button_box.add(relay_button)
         button_box.add(totp_button)
+        button_box.add(sync_button)
 
         self.status = toga.Label("Last sync: never", style=Pack(padding_top=5))
 
@@ -168,6 +170,14 @@ class MainWindow(toga.Window):
         win = TotpViewerWindow(self.controller, self.entries)
         win.show()
 
+    def start_vault_sync(self, widget: toga.Widget | None = None) -> None:
+        """Schedule a background vault synchronization."""
+
+        async def _runner() -> None:
+            self.nostr.start_background_vault_sync()
+
+        self.controller.loop.create_task(_runner())
+
     # --- PubSub callbacks -------------------------------------------------
     def sync_started(self, *args: object, **kwargs: object) -> None:
         self.status.text = "Syncing..."
@@ -307,6 +317,8 @@ class EntryDialog(toga.Window):
                     break
 
         self.close()
+        # schedule vault sync after saving
+        getattr(self.main, "start_vault_sync", lambda *_: None)()
 
 
 class SearchDialog(toga.Window):
diff --git a/src/tests/test_gui_sync.py b/src/tests/test_gui_sync.py
new file mode 100644
index 0000000..6ef1ed2
--- /dev/null
+++ b/src/tests/test_gui_sync.py
@@ -0,0 +1,77 @@
+import os
+import types
+import asyncio
+import toga
+import pytest
+
+from seedpass.core.pubsub import bus
+from seedpass_gui.app import MainWindow
+
+
+class DummyEntries:
+    def list_entries(self, sort_by="index", filter_kind=None, include_archived=False):
+        return []
+
+    def search_entries(self, q):
+        return []
+
+
+class DummyNostr:
+    def __init__(self):
+        self.called = False
+
+    def start_background_vault_sync(self):
+        self.called = True
+
+    def list_relays(self):
+        return []
+
+
+class DummyController:
+    def __init__(self, loop):
+        self.loop = loop
+        self.lock_window = types.SimpleNamespace(show=lambda: None)
+        self.main_window = None
+        self.vault_service = None
+        self.entry_service = None
+        self.nostr_service = None
+
+
+@pytest.fixture(autouse=True)
+def set_backend():
+    os.environ["TOGA_BACKEND"] = "toga_dummy"
+    asyncio.set_event_loop(asyncio.new_event_loop())
+
+
+def test_start_vault_sync_schedules_task():
+    toga.App("T", "o")
+
+    tasks = []
+
+    def create_task(coro):
+        tasks.append(coro)
+
+    loop = types.SimpleNamespace(create_task=create_task)
+    ctrl = DummyController(loop)
+    nostr = DummyNostr()
+    win = MainWindow(ctrl, None, DummyEntries(), nostr)
+
+    win.start_vault_sync()
+    assert tasks
+    asyncio.get_event_loop().run_until_complete(tasks[0])
+    assert nostr.called
+    win.cleanup()
+
+
+def test_status_updates_on_bus_events():
+    toga.App("T2", "o2")
+    loop = types.SimpleNamespace(create_task=lambda c: None)
+    ctrl = DummyController(loop)
+    nostr = DummyNostr()
+    win = MainWindow(ctrl, None, DummyEntries(), nostr)
+
+    bus.publish("sync_started")
+    assert win.status.text == "Syncing..."
+    bus.publish("sync_finished")
+    assert "Last sync:" in win.status.text
+    win.cleanup()