feat(firebaseai): add Google Maps Grounding support

packages/firebase_ai/firebase_ai/example/lib/main.dart

@@ -29,6 +29,7 @@ import 'pages/json_schema_page.dart';
 import 'pages/multimodal_page.dart';
 import 'pages/schema_page.dart';
 import 'pages/server_template_page.dart';
+import 'pages/grounding_page.dart';
 import 'pages/token_count_page.dart';
 
 void main() async {
@@ -172,6 +173,11 @@ class _HomeScreenState extends State<HomeScreen> {
           title: 'Server Template',
           useVertexBackend: useVertexBackend,
         );
+      case 10:
+        return GroundingPage(
+          title: 'Grounding',
+          useVertexBackend: useVertexBackend,
+        );
 
       default:
         // Fallback to the first page in case of an unexpected index
@@ -299,6 +305,13 @@ class _HomeScreenState extends State<HomeScreen> {
             label: 'Server',
             tooltip: 'Server Template',
           ),
+          BottomNavigationBarItem(
+            icon: Icon(
+              Icons.location_on,
+            ),
+            label: 'Grounding',
+            tooltip: 'Search & Maps Grounding',
+          ),
         ],
         currentIndex: _selectedIndex,
         onTap: _onItemTapped,

packages/firebase_ai/firebase_ai/example/lib/pages/grounding_page.dart

@@ -0,0 +1,303 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import 'package:firebase_auth/firebase_auth.dart';
+import 'package:flutter/material.dart';
+import 'package:firebase_ai/firebase_ai.dart';
+import '../widgets/message_widget.dart';
+
+class GroundingPage extends StatefulWidget {
+  const GroundingPage({
+    super.key,
+    required this.title,
+    required this.useVertexBackend,
+  });
+
+  final String title;
+  final bool useVertexBackend;
+
+  @override
+  State<GroundingPage> createState() => _GroundingPageState();
+}
+
+class _GroundingPageState extends State<GroundingPage> {
+  GenerativeModel? _model;
+  final ScrollController _scrollController = ScrollController();
+  final TextEditingController _textController = TextEditingController();
+  final TextEditingController _latController = TextEditingController();
+  final TextEditingController _lngController = TextEditingController();
+  final FocusNode _textFieldFocus = FocusNode();
+  final List<MessageData> _messages = <MessageData>[];
+
+  bool _loading = false;
+  bool _enableSearchGrounding = false;
+  bool _enableMapsGrounding = false;
+
+  @override
+  void initState() {
+    super.initState();
+    _latController.text = '37.422'; // Default Googleplex lat
+    _lngController.text = '-122.084'; // Default Googleplex lng
+  }
+
+  void _initializeModel() {
+    List<Tool> tools = [];
+    ToolConfig? toolConfig;
+
+    if (_enableSearchGrounding) {
+      tools.add(Tool.googleSearch());
+    }
+
+    if (_enableMapsGrounding) {
+      tools.add(Tool.googleMaps());
+
+      final lat = double.tryParse(_latController.text);
+      final lng = double.tryParse(_lngController.text);
+
+      if (lat != null && lng != null) {
+        toolConfig = ToolConfig(
+          retrievalConfig: RetrievalConfig(
+            latLng: LatLng(latitude: lat, longitude: lng),
+          ),
+        );
+      }
+    }
+
+    final aiProvider = widget.useVertexBackend
+        ? FirebaseAI.vertexAI(auth: FirebaseAuth.instance)
+        : FirebaseAI.googleAI(auth: FirebaseAuth.instance);
+
+    _model = aiProvider.generativeModel(
+      model: 'gemini-2.5-flash',
+      tools: tools.isNotEmpty ? tools : null,
+      toolConfig: toolConfig,
+    );
+  }
+
+  void _scrollDown() {
+    WidgetsBinding.instance.addPostFrameCallback(
+      (_) => _scrollController.animateTo(
+        _scrollController.position.maxScrollExtent,
+        duration: const Duration(milliseconds: 750),
+        curve: Curves.easeOutCirc,
+      ),
+    );
+  }
+
+  Future<void> _sendPrompt(String message) async {
+    if (message.isEmpty) return;
+
+    _initializeModel(); // Re-initialize before sending to capture current toggles
+
+    setState(() {
+      _loading = true;
+    });
+
+    try {
+      _messages.add(MessageData(text: message, fromUser: true));
+
+      final response = await _model?.generateContent([Content.text(message)]);
+
+      var text = response?.text;
+
+      // Extract grounding metadata to display
+      final groundingMetadata =
+          response?.candidates.firstOrNull?.groundingMetadata;
+      if (groundingMetadata != null) {
+        final chunks = groundingMetadata.groundingChunks.map((chunk) {
+          if (chunk.web != null) {
+            final title = chunk.web!.title ?? chunk.web!.uri;
+            return '- [$title](${chunk.web!.uri})';
+          }
+          if (chunk.maps != null) {
+            final title = chunk.maps!.title ?? chunk.maps!.uri;
+            return '- [${title ?? 'Maps Result'}](${chunk.maps!.uri ?? ''})';
+          }
+          return '- Unknown chunk';
+        }).join('\n');
+
+        if (chunks.isNotEmpty) {
+          text = '$text\n\n**Grounding Sources:**\n$chunks';
+        }
+      }
+
+      _messages.add(MessageData(text: text, fromUser: false));
+
+      if (text == null) {
+        _showError('No response from API.');
+        return;
+      }
+    } catch (e) {
+      _showError(e.toString());
+    } finally {
+      if (mounted) {
+        _textController.clear();
+        setState(() {
+          _loading = false;
+        });
+        _textFieldFocus.requestFocus();
+        _scrollDown();
+      }
+    }
+  }
+
+  void _showError(String message) {
+    showDialog<void>(
+      context: context,
+      builder: (context) {
+        return AlertDialog(
+          title: const Text('Something went wrong'),
+          content: SingleChildScrollView(
+            child: SelectableText(message),
+          ),
+          actions: [
+            TextButton(
+              onPressed: () {
+                Navigator.of(context).pop();
+              },
+              child: const Text('OK'),
+            ),
+          ],
+        );
+      },
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(widget.title),
+      ),
+      body: Padding(
+        padding: const EdgeInsets.all(8),
+        child: Column(
+          children: [
+            Row(
+              children: [
+                Expanded(
+                  child: SwitchListTile(
+                    title: const Text(
+                      'Search Grounding',
+                      style: TextStyle(fontSize: 12),
+                    ),
+                    value: _enableSearchGrounding,
+                    onChanged: (bool value) {
+                      setState(() {
+                        _enableSearchGrounding = value;
+                      });
+                    },
+                  ),
+                ),
+                Expanded(
+                  child: SwitchListTile(
+                    title: const Text(
+                      'Maps Grounding',
+                      style: TextStyle(fontSize: 12),
+                    ),
+                    value: _enableMapsGrounding,
+                    onChanged: (bool value) {
+                      setState(() {
+                        _enableMapsGrounding = value;
+                      });
+                    },
+                  ),
+                ),
+              ],
+            ),
+            if (_enableMapsGrounding)
+              Padding(
+                padding: const EdgeInsets.symmetric(horizontal: 16),
+                child: Row(
+                  children: [
+                    Expanded(
+                      child: TextField(
+                        controller: _latController,
+                        decoration:
+                            const InputDecoration(labelText: 'Latitude'),
+                        keyboardType: const TextInputType.numberWithOptions(
+                          decimal: true,
+                          signed: true,
+                        ),
+                      ),
+                    ),
+                    const SizedBox(width: 16),
+                    Expanded(
+                      child: TextField(
+                        controller: _lngController,
+                        decoration:
+                            const InputDecoration(labelText: 'Longitude'),
+                        keyboardType: const TextInputType.numberWithOptions(
+                          decimal: true,
+                          signed: true,
+                        ),
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            const Divider(),
+            Expanded(
+              child: ListView.builder(
+                controller: _scrollController,
+                itemBuilder: (context, idx) {
+                  final message = _messages[idx];
+                  return MessageWidget(
+                    text: message.text,
+                    isFromUser: message.fromUser ?? false,
+                  );
+                },
+                itemCount: _messages.length,
+              ),
+            ),
+            Padding(
+              padding: const EdgeInsets.symmetric(
+                vertical: 25,
+                horizontal: 15,
+              ),
+              child: Row(
+                children: [
+                  Expanded(
+                    child: TextField(
+                      autofocus: true,
+                      focusNode: _textFieldFocus,
+                      controller: _textController,
+                      onSubmitted: _sendPrompt,
+                      decoration: const InputDecoration(
+                        hintText: 'Enter a prompt...',
+                      ),
+                    ),
+                  ),
+                  const SizedBox.square(dimension: 15),
+                  if (!_loading)
+                    IconButton(
+                      onPressed: () {
+                        _sendPrompt(_textController.text);
+                      },
+                      icon: Icon(
+                        Icons.send,
+                        color: Theme.of(context).colorScheme.primary,
+                      ),
+                    )
+                  else
+                    const CircularProgressIndicator(),
+                ],
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}