diff --git a/lib/app/app_controller_desktop_workspace_execution.dart b/lib/app/app_controller_desktop_workspace_execution.dart
index af5f8751..7f8625a6 100644
--- a/lib/app/app_controller_desktop_workspace_execution.dart
+++ b/lib/app/app_controller_desktop_workspace_execution.dart
@@ -53,6 +53,23 @@ extension AppControllerDesktopWorkspaceExecution on AppController {
     final currentTarget = assistantExecutionTargetForSession(
       sessionsControllerInternal.currentSessionKey,
     );
+    final shouldRefreshAgentProviders =
+        resolvedTarget.isAgent && assistantProviderCatalog.isEmpty;
+    if (shouldRefreshAgentProviders) {
+      try {
+        await refreshSingleAgentCapabilitiesInternal(forceRefresh: true);
+      } catch (_) {
+        // Keep target selection interactive even when a just-in-time
+        // capabilities refresh fails. The provider picker will remain hidden
+        // until the next successful refresh.
+      }
+      if (currentTarget == resolvedTarget &&
+          settings.assistantExecutionTarget == resolvedTarget) {
+        recomputeTasksInternal();
+        notifyIfActiveInternal();
+        return;
+      }
+    }
     if (currentTarget == resolvedTarget &&
         settings.assistantExecutionTarget == resolvedTarget) {
       return;
diff --git a/test/runtime/assistant_execution_target_test.dart b/test/runtime/assistant_execution_target_test.dart
index 6598ffc6..65c2dd6b 100644
--- a/test/runtime/assistant_execution_target_test.dart
+++ b/test/runtime/assistant_execution_target_test.dart
@@ -1,5 +1,10 @@
+import 'dart:convert';
+import 'dart:io';
+
 import 'package:flutter_test/flutter_test.dart';
+import 'package:xworkmate/app/app_controller.dart';
 import 'package:xworkmate/runtime/runtime_models.dart';
+import 'package:xworkmate/runtime/secure_config_store.dart';
 
 void main() {
   group('AssistantExecutionTarget', () {
@@ -45,5 +50,130 @@ void main() {
       expect(provider.providerId, kCanonicalGatewayProviderId);
       expect(provider.label, kCanonicalGatewayProviderLabel);
     });
+
+    test(
+      'refreshes agent provider catalog when agent mode is selected with an empty catalog',
+      () async {
+        final capture = await _startCapabilityServer();
+        addTearDown(capture.close);
+
+        final storeRoot = await Directory.systemTemp.createTemp(
+          'xworkmate-agent-provider-refresh-',
+        );
+        addTearDown(() async {
+          if (await storeRoot.exists()) {
+            await storeRoot.delete(recursive: true);
+          }
+        });
+
+        final store = SecureConfigStore(
+          secretRootPathResolver: () async => '${storeRoot.path}/secrets',
+          appDataRootPathResolver: () async => '${storeRoot.path}/app-data',
+          supportRootPathResolver: () async => '${storeRoot.path}/support',
+          enableSecureStorage: false,
+        );
+        await store.initialize();
+        await store.saveAccountSyncState(
+          AccountSyncState.defaults().copyWith(
+            syncedDefaults: AccountRemoteProfile.defaults().copyWith(
+              bridgeServerUrl: capture.baseEndpoint.toString(),
+            ),
+            syncState: 'ready',
+          ),
+        );
+
+        final controller = AppController(
+          store: store,
+          environmentOverride: const <String, String>{
+            'BRIDGE_AUTH_TOKEN': 'bridge-token',
+          },
+        );
+        addTearDown(controller.dispose);
+
+        await controller.sessionsController.switchSession('session-1');
+        await _waitForRequest(capture, minimumCount: 1);
+
+        expect(controller.assistantProviderCatalog, isEmpty);
+
+        await controller.setAssistantExecutionTarget(
+          AssistantExecutionTarget.agent,
+        );
+
+        expect(
+          controller.assistantProviderCatalog.map((item) => item.providerId),
+          containsAll(<String>['codex', 'opencode', 'gemini']),
+        );
+        expect(capture.requestCount, greaterThanOrEqualTo(2));
+        expect(capture.lastAuthorizationHeader, 'Bearer bridge-token');
+      },
+    );
   });
 }
+
+Future<void> _waitForRequest(
+  _CapabilityServerCapture capture, {
+  required int minimumCount,
+}) async {
+  for (var index = 0; index < 20; index += 1) {
+    if (capture.requestCount >= minimumCount) {
+      return;
+    }
+    await Future<void>.delayed(const Duration(milliseconds: 100));
+  }
+  fail('Timed out waiting for $minimumCount capability requests');
+}
+
+Future<_CapabilityServerCapture> _startCapabilityServer() async {
+  final server = await HttpServer.bind(InternetAddress.loopbackIPv4, 0);
+  final capture = _CapabilityServerCapture._(
+    server,
+    Uri.parse('http://127.0.0.1:${server.port}'),
+  );
+  server.listen((request) async {
+    capture.requestCount += 1;
+    capture.lastAuthorizationHeader =
+        request.headers.value(HttpHeaders.authorizationHeader) ?? '';
+    await utf8.decoder.bind(request).join();
+    if (capture.requestCount == 1) {
+      request.response.statusCode = HttpStatus.internalServerError;
+      request.response.headers.contentType = ContentType.json;
+      request.response.write(
+        jsonEncode(<String, dynamic>{
+          'error': <String, dynamic>{'message': 'startup refresh failed'},
+        }),
+      );
+      await request.response.close();
+      return;
+    }
+
+    request.response.headers.contentType = ContentType.json;
+    request.response.write(
+      jsonEncode(<String, dynamic>{
+        'jsonrpc': '2.0',
+        'id': 'capabilities',
+        'result': <String, dynamic>{
+          'singleAgent': true,
+          'multiAgent': true,
+          'providerCatalog': <Map<String, dynamic>>[
+            <String, dynamic>{'providerId': 'codex', 'label': 'Codex'},
+            <String, dynamic>{'providerId': 'opencode', 'label': 'OpenCode'},
+            <String, dynamic>{'providerId': 'gemini', 'label': 'Gemini'},
+          ],
+        },
+      }),
+    );
+    await request.response.close();
+  });
+  return capture;
+}
+
+class _CapabilityServerCapture {
+  _CapabilityServerCapture._(this._server, this.baseEndpoint);
+
+  final HttpServer _server;
+  final Uri baseEndpoint;
+  int requestCount = 0;
+  String lastAuthorizationHeader = '';
+
+  Future<void> close() => _server.close(force: true);
+}