Adding the posibility to proxy the google route requests

example/lib/main.dart

@@ -77,9 +77,14 @@ class MainScreenState extends State<MainScreen> with TickerProviderStateMixin {
 
 // Legacy API Example (Backward Compatibility)
 class LegacyMapScreen extends StatefulWidget {
-  final String apiKey;
+  final String? apiKey;
+  final Uri? proxy;
 
-  const LegacyMapScreen({super.key, required this.apiKey});
+  const LegacyMapScreen({
+    super.key,
+    this.proxy,
+    this.apiKey,
+  });
 
   @override
   LegacyMapScreenState createState() => LegacyMapScreenState();
@@ -99,7 +104,7 @@ class LegacyMapScreenState extends State<LegacyMapScreen> {
   @override
   void initState() {
     super.initState();
-    polylinePoints = PolylinePoints(apiKey: widget.apiKey);
+    polylinePoints = PolylinePoints(proxy: widget.proxy, apiKey: widget.apiKey);
 
     _addMarker(LatLng(_originLatitude, _originLongitude), "origin",
         BitmapDescriptor.defaultMarker);
@@ -246,9 +251,15 @@ class LegacyMapScreenState extends State<LegacyMapScreen> {
 
 // Custom Headers Example (Android-restricted API keys)
 class CustomHeadersMapScreen extends StatefulWidget {
-  final String apiKey;
+  final String? apiKey;
 
-  const CustomHeadersMapScreen({super.key, required this.apiKey});
+  final Uri? proxy;
+
+  const CustomHeadersMapScreen({
+    super.key,
+    this.proxy,
+    this.apiKey,
+  });
 
   @override
   CustomHeadersMapScreenState createState() => CustomHeadersMapScreenState();
@@ -274,7 +285,8 @@ class CustomHeadersMapScreenState extends State<CustomHeadersMapScreen> {
   @override
   void initState() {
     super.initState();
-    polylinePoints = PolylinePoints.enhanced(widget.apiKey);
+    polylinePoints =
+        PolylinePoints.enhanced(proxy: widget.proxy, apiKey: widget.apiKey);
     _addMarker(LatLng(_originLatitude, _originLongitude), "origin",
         BitmapDescriptor.defaultMarker);
     _addMarker(LatLng(_destLatitude, _destLongitude), "destination",
@@ -497,9 +509,15 @@ class CustomHeadersMapScreenState extends State<CustomHeadersMapScreen> {
 
 // Routes API Example (Enhanced Features)
 class RoutesApiMapScreen extends StatefulWidget {
-  final String apiKey;
+  final String? apiKey;
+
+  final Uri? proxy;
 
-  const RoutesApiMapScreen({super.key, required this.apiKey});
+  const RoutesApiMapScreen({
+    super.key,
+    this.proxy,
+    this.apiKey,
+  });
 
   @override
   RoutesApiMapScreenState createState() => RoutesApiMapScreenState();
@@ -520,7 +538,8 @@ class RoutesApiMapScreenState extends State<RoutesApiMapScreen> {
   @override
   void initState() {
     super.initState();
-    polylinePoints = PolylinePoints.enhanced(widget.apiKey);
+    polylinePoints =
+        PolylinePoints.enhanced(proxy: widget.proxy, apiKey: widget.apiKey);
     _addMarker(LatLng(_originLatitude, _originLongitude), "origin",
         BitmapDescriptor.defaultMarker);
     _addMarker(LatLng(_destLatitude, _destLongitude), "destination",
@@ -762,9 +781,11 @@ class RoutesApiMapScreenState extends State<RoutesApiMapScreen> {
 
 // Two-Wheeler Example (Routes API Exclusive Feature)
 class TwoWheelerMapScreen extends StatefulWidget {
-  final String apiKey;
+  final String? apiKey;
 
-  const TwoWheelerMapScreen({super.key, required this.apiKey});
+  final Uri? proxy;
+
+  const TwoWheelerMapScreen({super.key, this.proxy, this.apiKey});
 
   @override
   TwoWheelerMapScreenState createState() => TwoWheelerMapScreenState();
@@ -786,7 +807,10 @@ class TwoWheelerMapScreenState extends State<TwoWheelerMapScreen> {
   @override
   void initState() {
     super.initState();
-    polylinePointsV2 = PolylinePoints.enhanced(widget.apiKey);
+    polylinePointsV2 = PolylinePoints.enhanced(
+      proxy: widget.proxy,
+      apiKey: widget.apiKey,
+    );
     _addMarker(LatLng(_originLatitude, _originLongitude), "origin",
         BitmapDescriptor.defaultMarker);
     _addMarker(LatLng(_destLatitude, _destLongitude), "destination",

lib/src/network/network_provider.dart

@@ -26,16 +26,27 @@ class NetworkProvider {
   /// Get route using legacy Directions API (for backward compatibility)
   /// Supports only basic features
   ///
+  /// @param [proxy] - Proxy the request to hide the google key application on your requests parameters to prevent bad actors from reaching and using the key exposed in the code.
   /// @param [apiKey] - Google Maps API key
   /// @param [PolylineRequest] - PolylineRequest object
   /// @param [timeout] - Optional timeout for the request
   /// @return [PolylineResult] object with decoded points
   static Future<PolylineResult> getRouteBetweenCoordinates(
-    String googleApiKey,
+    Uri? proxy,
+    String? googleApiKey,
     PolylineRequest request, {
     Duration? timeout,
   }) async {
-    final uri = _buildDirectionsUri(googleApiKey, request);
+    assert(
+        (proxy == null && googleApiKey != null && googleApiKey.isNotEmpty) ||
+            (proxy != null && googleApiKey == null),
+        "Google API Key cannot be empty if proxy isn't provided");
+
+    final uri = _buildDirectionsUri(
+      proxy: proxy,
+      apiKey: googleApiKey,
+      request: request,
+    );
 
     try {
       final response = await http
@@ -62,19 +73,26 @@ class NetworkProvider {
   /// Get route using new Routes API with enhanced features
   /// Supports all Routes API features
   ///
+  /// @param [proxy] - Proxy the request to hide the google key application on your requests parameters to prevent bad actors from reaching and using the key exposed in the code.
   /// @param [apiKey] - Google Maps API key
   /// @param [RoutesApiRequest] - RoutesApiRequest object
   /// @param [timeout] - Optional timeout for the request
   /// @return [RoutesApiResponse] object with decoded points
   static Future<RoutesApiResponse> getRouteBetweenCoordinatesV2(
-    String googleApiKey,
+    Uri? proxy,
+    String? googleApiKey,
     RoutesApiRequest request, {
     Duration? timeout,
   }) async {
+    assert(
+        (proxy == null && googleApiKey != null && googleApiKey.isNotEmpty) ||
+            (proxy != null && googleApiKey == null),
+        "Google API Key cannot be empty if proxy isn't provided");
+
     try {
       final response = await http
           .post(
-            Uri.parse(_routesBaseUrl),
+            proxy ?? Uri.parse(_routesBaseUrl),
             headers: _getRoutesHeaders(googleApiKey, request),
             body: json.encode(request.toJson()),
           )
@@ -97,14 +115,22 @@ class NetworkProvider {
   }
 
   /// Build URI for legacy Directions API
-  static Uri _buildDirectionsUri(String apiKey, PolylineRequest request) {
+  static Uri _buildDirectionsUri({
+    Uri? proxy,
+    String? apiKey,
+    required PolylineRequest request,
+  }) {
     final queryParams = <String, String>{
-      'key': apiKey,
       'origin': _formatLocation(request.origin),
       'destination': _formatLocation(request.destination),
       'mode': request.mode.name,
     };
 
+    // Adds Api key to parameters if given.
+    if (apiKey != null) {
+      queryParams.addAll({'key': apiKey});
+    }
+
     // Add waypoints if present
     if (request.wayPoints.isNotEmpty) {
       final waypoints = request.wayPoints
@@ -133,7 +159,8 @@ class NetworkProvider {
       queryParams['optimize'] = 'true';
     }
 
-    return Uri.parse(_directionsBaseUrl).replace(queryParameters: queryParams);
+    return (proxy ?? Uri.parse(_directionsBaseUrl))
+        .replace(queryParameters: queryParams);
   }
 
   /// Format location for API request
@@ -163,16 +190,21 @@ class NetworkProvider {
 
   /// Get headers for Routes API
   static Map<String, String> _getRoutesHeaders(
-    String apiKey,
+    String? apiKey,
     RoutesApiRequest request,
   ) {
     final headers = {
       'Content-Type': 'application/json',
-      'X-Goog-Api-Key': apiKey,
       'X-Goog-FieldMask': request.getFieldMask(),
       'User-Agent': 'flutter_polyline_points/3.0.0',
     };
 
+    if (apiKey != null) {
+      headers.addAll({
+        'X-Goog-Api-Key': apiKey,
+      });
+    }
+
     // Add optional headers
     if (request.languageCode != null) {
       headers['Accept-Language'] = request.languageCode!;
@@ -238,7 +270,10 @@ class NetworkProvider {
   }
 
   /// Check API availability and capabilities
-  static Future<Map<String, bool>> checkApiAvailability(String apiKey) async {
+  static Future<Map<String, bool>> checkApiAvailability(
+    Uri? proxy,
+    String? apiKey,
+  ) async {
     final results = <String, bool>{};
 
     // Test Directions API
@@ -249,7 +284,7 @@ class NetworkProvider {
         mode: TravelMode.driving,
       );
 
-      await getRouteBetweenCoordinates(apiKey, testRequest,
+      await getRouteBetweenCoordinates(proxy, apiKey, testRequest,
           timeout: Duration(seconds: 10));
       results['directions_api'] = true;
     } catch (e) {
@@ -263,7 +298,7 @@ class NetworkProvider {
         destination: PointLatLng(37.7849, -122.4094),
       );
 
-      await getRouteBetweenCoordinatesV2(apiKey, testRequest,
+      await getRouteBetweenCoordinatesV2(proxy, apiKey, testRequest,
           timeout: Duration(seconds: 10));
       results['routes_api'] = true;
     } catch (e) {

lib/src/polyline_points.dart

@@ -14,8 +14,11 @@ import 'routes_api/routes_response.dart';
 /// Provides backward compatibility while enabling access to advanced routing features
 // ignore_for_file: deprecated_member_use_from_same_package
 class PolylinePoints {
+  /// Proxy for circumventing exposing your API key in your code.
+  final Uri? proxy;
+
   /// Google API key for accessing routing services
-  final String apiKey;
+  final String? apiKey;
 
   /// Default timeout for API requests
   final Duration defaultTimeout;
@@ -25,34 +28,50 @@ class PolylinePoints {
 
   /// Create a new PolylinePointsV2 instance
   PolylinePoints({
-    required this.apiKey,
+    this.proxy,
+    this.apiKey,
     this.defaultTimeout = const Duration(seconds: 30),
     this.preferRoutesApi = true,
-  });
+  }) {
+    assert(
+        (proxy == null && apiKey != null && apiKey!.isNotEmpty) ||
+            (proxy != null && apiKey == null),
+        "Google API Key cannot be empty if proxy isn't provided");
+  }
 
   /// Create instance optimized for legacy API usage
-  factory PolylinePoints.legacy(String apiKey) {
+  factory PolylinePoints.legacy({
+    Uri? proxy,
+    String? apiKey,
+  }) {
     return PolylinePoints(
+      proxy: proxy,
       apiKey: apiKey,
       preferRoutesApi: false,
     );
   }
 
   /// Create instance optimized for Routes API usage
-  factory PolylinePoints.enhanced(String apiKey) {
+  factory PolylinePoints.enhanced({
+    Uri? proxy,
+    String? apiKey,
+  }) {
     return PolylinePoints(
+      proxy: proxy,
       apiKey: apiKey,
       preferRoutesApi: true,
     );
   }
 
   /// Create instance with custom configuration
   factory PolylinePoints.custom({
-    required String apiKey,
+    Uri? proxy,
+    String? apiKey,
     Duration? timeout,
     bool? preferRoutesApi,
   }) {
     return PolylinePoints(
+      proxy: proxy,
       apiKey: apiKey,
       defaultTimeout: timeout ?? const Duration(seconds: 30),
       preferRoutesApi: preferRoutesApi ?? true,
@@ -71,6 +90,7 @@ class PolylinePoints {
     Duration? timeout,
   }) async {
     return NetworkProvider.getRouteBetweenCoordinates(
+      proxy,
       apiKey,
       request,
       timeout: timeout ?? defaultTimeout,
@@ -94,6 +114,7 @@ class PolylinePoints {
     Duration? timeout,
   }) async {
     return NetworkProvider.getRouteBetweenCoordinatesV2(
+      proxy,
       apiKey,
       request,
       timeout: timeout ?? defaultTimeout,
@@ -127,7 +148,7 @@ class PolylinePoints {
 
   /// Check which APIs are available with the current API key
   Future<Map<String, bool>> checkApiAvailability() async {
-    return NetworkProvider.checkApiAvailability(apiKey);
+    return NetworkProvider.checkApiAvailability(proxy, apiKey);
   }
 
   /// Get API usage recommendation for a given request