Support experimental messages (#4)

And demo debug messages in the example client

example/lib/main.dart

@@ -40,6 +40,7 @@ class MyHomePage extends StatefulWidget {
 
 class _MyHomePageState extends State<MyHomePage> {
   UltravoxSession? _session;
+  bool debug = false;
 
   @override
   void dispose() {
@@ -60,7 +61,8 @@ class _MyHomePageState extends State<MyHomePage> {
       return;
     }
     setState(() {
-      _session = UltravoxSession.create();
+      _session =
+          UltravoxSession.create(experimentalMessages: debug ? {"debug"} : {});
     });
     _session!.state.addListener(_onStateChange);
     await _session!.joinCall(joinUrl);
@@ -94,10 +96,24 @@ class _MyHomePageState extends State<MyHomePage> {
           mainAxisAlignment: MainAxisAlignment.center,
           children: [
             textInput,
-            ElevatedButton(
-              onPressed: () => _startCall(textController.text),
-              child: const Text('Start Call'),
-            ),
+            const SizedBox(height: 20, width: 20),
+            Row(
+              mainAxisAlignment: MainAxisAlignment.start,
+              children: [
+                const Text.rich(TextSpan(
+                    text: 'Debug',
+                    style: TextStyle(fontWeight: FontWeight.bold))),
+                Switch(
+                  value: debug,
+                  onChanged: (value) => setState(() => debug = value),
+                ),
+                const Spacer(),
+                ElevatedButton(
+                  onPressed: () => _startCall(textController.text),
+                  child: const Text('Start Call'),
+                ),
+              ],
+            )
           ],
         ),
       ));
@@ -128,6 +144,17 @@ class _MyHomePageState extends State<MyHomePage> {
           child: const Text('End Call'),
         ),
       );
+      if (debug) {
+        mainBodyChildren.add(const SizedBox(height: 20));
+        mainBodyChildren.add(const Text.rich(TextSpan(
+            text: 'Last Debug Message:',
+            style: TextStyle(fontWeight: FontWeight.w700))));
+
+        if (_session!.state.lastExperimentalMessage != null) {
+          mainBodyChildren.add(DebugMessageWidget(
+              message: _session!.state.lastExperimentalMessage!));
+        }
+      }
     }
     return Scaffold(
       appBar: AppBar(
@@ -171,3 +198,27 @@ class TranscriptWidget extends StatelessWidget {
     ]));
   }
 }
+
+class DebugMessageWidget extends StatelessWidget {
+  const DebugMessageWidget({super.key, required this.message});
+
+  final Map<String, dynamic> message;
+
+  @override
+  Widget build(BuildContext context) {
+    List<InlineSpan> children = [];
+    for (final entry in message.entries) {
+      children.add(TextSpan(
+        text: '${entry.key}: ',
+        style: const TextStyle(fontWeight: FontWeight.bold),
+      ));
+      children.add(TextSpan(text: '${entry.value}\n'));
+    }
+    return RichText(
+      text: TextSpan(
+        style: Theme.of(context).textTheme.bodySmall,
+        children: children,
+      ),
+    );
+  }
+}

lib/src/session.dart

@@ -72,9 +72,11 @@ class Transcript {
 class UltravoxSessionState extends ChangeNotifier {
   final _transcripts = <Transcript>[];
   var _status = UltravoxSessionStatus.disconnected;
+  Map<String, dynamic>? _lastExperimentalMessage;
 
   UltravoxSessionStatus get status => _status;
   List<Transcript> get transcripts => List.unmodifiable(_transcripts);
+  Map<String, dynamic>? get lastExperimentalMessage => _lastExperimentalMessage;
 
   set status(UltravoxSessionStatus value) {
     _status = value;
@@ -92,18 +94,26 @@ class UltravoxSessionState extends ChangeNotifier {
     }
     notifyListeners();
   }
+
+  set lastExperimentalMessage(Map<String, dynamic>? value) {
+    _lastExperimentalMessage = value;
+    notifyListeners();
+  }
 }
 
 /// Manages a single session with Ultravox.
 class UltravoxSession {
   final _state = UltravoxSessionState();
+  final Set<String> _experimentalMessages;
   final lk.Room _room;
   final lk.EventsListener<lk.RoomEvent> _listener;
   late WebSocketChannel _wsChannel;
 
-  UltravoxSession(this._room) : _listener = _room.createListener();
+  UltravoxSession(this._room, this._experimentalMessages)
+      : _listener = _room.createListener();
 
-  UltravoxSession.create() : this(lk.Room());
+  UltravoxSession.create({Set<String>? experimentalMessages})
+      : this(lk.Room(), experimentalMessages ?? {});
 
   UltravoxSessionState get state => _state;
 
@@ -113,7 +123,15 @@ class UltravoxSession {
       throw Exception('Cannot join a new call while already in a call');
     }
     _changeStatus(UltravoxSessionStatus.connecting);
-    _wsChannel = WebSocketChannel.connect(Uri.parse(joinUrl));
+    var url = Uri.parse(joinUrl);
+    if (_experimentalMessages.isNotEmpty) {
+      final queryParameters = Map<String, String>.from(url.queryParameters)
+        ..addAll({
+          'experimentalMessages': _experimentalMessages.join(','),
+        });
+      url = url.replace(queryParameters: queryParameters);
+    }
+    _wsChannel = WebSocketChannel.connect(url);
     await _wsChannel.ready;
     _wsChannel.stream.listen((event) async {
       await _handleSocketMessage(event);
@@ -195,7 +213,9 @@ class UltravoxSession {
         }
         break;
       case 'transcript':
-        final medium = data['medium'] == 'voice' ? Medium.voice : Medium.text;
+        final medium = data['transcript']['medium'] == 'voice'
+            ? Medium.voice
+            : Medium.text;
         final transcript = Transcript(
           text: data['transcript']['text'] as String,
           isFinal: data['transcript']['final'] as bool,
@@ -231,7 +251,9 @@ class UltravoxSession {
         }
         break;
       default:
-      // ignore
+        if (_experimentalMessages.isNotEmpty) {
+          _state.lastExperimentalMessage = data as Map<String, dynamic>;
+        }
     }
   }
 }

pubspec.yaml

@@ -8,6 +8,13 @@ topics:
   - audio
   - ai
   - llms
+platforms:
+  android:
+  ios:
+  linux:
+  macos:
+  web:
+  windows:
 
 environment:
   sdk: ^3.5.1