Make new tasks have unique IDs.

Author: gspencergoog

packages/a2a_dart/lib/src/client/a2a_client.dart

@@ -25,6 +25,7 @@ import 'transport.dart';
 /// Events (SSE).
 class A2AClient {
   final _log = Logger('A2AClient');
+  int _nextId = 1;
 
   /// The base URL of the A2A server.
   final String url;
@@ -94,7 +95,7 @@ class A2AClient {
       'jsonrpc': '2.0',
       'method': 'create_task',
       'params': {'message': message.toJson()},
-      'id': 1,
+      'id': _nextId++,
     };
     _log.info('Creating task with message: ${message.toJson()}');
     final response = await transport.send(request);
@@ -120,7 +121,7 @@ class A2AClient {
       'jsonrpc': '2.0',
       'method': 'message/stream',
       'params': {'message': message.toJson()},
-      'id': 1,
+      'id': _nextId++,
     };
     _log.info('Sending message stream: ${message.toJson()}');
     return transport.sendStream(request);
@@ -136,7 +137,7 @@ class A2AClient {
       'jsonrpc': '2.0',
       'method': 'execute_task',
       'params': {'task_id': taskId},
-      'id': 1,
+      'id': _nextId++,
     };
     _log.info('Executing task $taskId');
     return transport.sendStream(request).map(

packages/a2a_dart/test/client/a2a_client_test.dart

@@ -102,6 +102,29 @@ void main() {
       );
     });
 
+    test('sends unique request IDs', () async {
+      final message = Message(
+        messageId: '1',
+        role: Role.user,
+        parts: [Part.text(text: 'Hello')],
+      );
+      final taskJson = {
+        'id': '123',
+        'contextId': '456',
+        'status': {'state': 'submitted'},
+      };
+
+      when(
+        mockTransport.send(any),
+      ).thenAnswer((_) async => {'result': taskJson});
+
+      await client.createTask(message);
+      await client.createTask(message);
+
+      final requests = verify(mockTransport.send(captureAny)).captured;
+      expect(requests[0]['id'], isNot(equals(requests[1]['id'])));
+    });
+
     test('executeTask returns a stream of StreamingEvents on success', () {
       final streamController = StreamController<Map<String, dynamic>>();
       final eventJson = {