[Help]: Could not find a Task/Message for 84ced8e6-3705-41c6-9158-f2b880463a32

What happened?

Hi,

I encountered a problem when integrating the A2A Java SDK 1.1.0.final with Spring Boot 4, and I cannot solve it myself. I am asking for help here.

Following the approach of A2A Java SDK for Spring Framework project, I attempted to migrate the helloworld project of the a2aproject to Spring Boot 4. Unfortunately, I encountered an error message when testing SendMessage.

Could not find a Task/Message for 84ced8e6-3705-41c6-9158-f2b880463a32

Tracing the program revealed that TaskManager.saveTask(...) was never called during runtime. Therefore, when ResultAggregator.consumeAndBreakOnInterrupt(...) attempted to call TaskManager.getTask(), the program failed because the task had never been stored in TaskStore.

I can't figure out where the problem is. It might be that I haven't understood some special configuration details in v1.0.0.final, leading to incorrect A2A server configuration, or the controller may have missed processing something when receiving messages. I sincerely request that an expert provide guidance and help me find the problem.

I've minimized my project, including only the code needed for SendMessage, so you can check for issues.

ServerConfig is used to assemble the A2A Java SDK server components.
SendMessageController is used to receive SendMessage messages from the client.

Use Postman to test.

Healder: "A2A-Version: 1.0".

Body：

{
  "jsonrpc": "2.0",
  "id": "6e7bf51a-f364-42d7-a060-343da3cc4f43",
  "method": "SendMessage",
  "params": {
    "message": {
      "messageId": "messageId-1",
      "role": "ROLE_USER",
      "parts": [
        {
          "text": "Can you check systems?"
        }
      ]
    }
  }
}

Response: 200 OK

{
    "error": {
        "cause": null,
        "code": -32603,
        "details": {},
        "localizedMessage": "Could not find a Task/Message for 84ced8e6-3705-41c6-9158-f2b880463a32",
        "message": "Could not find a Task/Message for 84ced8e6-3705-41c6-9158-f2b880463a32",
        "stackTrace": [
            {
                "classLoaderName": "app",
                "className": "org.a2aproject.sdk.server.tasks.ResultAggregator",
                "fileName": "ResultAggregator.java",
                "lineNumber": 253,
                "methodName": "consumeAndBreakOnInterrupt",
                "moduleName": null,
                "moduleVersion": null,
                "nativeMethod": false
            },
            {
                "classLoaderName": "app",
                "className": "org.a2aproject.sdk.server.requesthandlers.DefaultRequestHandler",
                "fileName": "DefaultRequestHandler.java",
                "lineNumber": 483,
                "methodName": "onMessageSend",
                "moduleName": null,
                "moduleVersion": null,
                "nativeMethod": false
            },
            {
                "classLoaderName": "app",
                "className": "org.a2aproject.sdk.transport.jsonrpc.handler.JSONRPCHandler",
                "fileName": "JSONRPCHandler.java",
                "lineNumber": 234,
                "methodName": "onMessageSend",
                "moduleName": null,
                "moduleVersion": null,
                "nativeMethod": false
            },
            {
                "classLoaderName": "app",
                "className": "llms.devs.a2a.server.controller.SendMessageController",
                "fileName": "SendMessageController.java",
                "lineNumber": 57,
                "methodName": "handleSendMessageRpc",
                "moduleName": null,
                "moduleVersion": null,
                "nativeMethod": false
            },
            .......
        ],
        "suppressed": []
    },
    "id": "6e7bf51a-f364-42d7-a060-343da3cc4f43",
    "jsonrpc": "2.0",
    "result": null
}

This is the log file.

Thanks for your help.

Relevant log output

Code of Conduct

I agree to follow this project's Code of Conduct

Based on the summary in #997, I adjusted the way Spring beans are constructed in ServerConfig, then, the expected response was received.

The change are:

Use the constructor of DefaultRequestHandler to construct an instance of DefaultRequestHandler.
Construct a separate MainEventBusProcessor bean, and then inject it into the DefaultRequestHandler bean.

That is, the following construct:

	@Bean
	public RequestHandler requestHandler(AgentExecutor agentExecutor, TaskStore taskStore, QueueManager queueManager,
	                                     PushNotificationConfigStore pushConfigStore,
										 MainEventBus mainEventBus,
										 PushNotificationSender pushSender,
	                                     @Qualifier("a2aInternal") Executor executor) {
		ExecutorService eventConsumerExecutor = Executors.newFixedThreadPool(3);
		return new DefaultRequestHandler(agentExecutor, taskStore, queueManager, pushConfigStore,
				new MainEventBusProcessor(mainEventBus, taskStore, pushSender, queueManager),
				executor,
				eventConsumerExecutor);
	}

becomes:

	@Bean
	public MainEventBusProcessor mainEventBusProcessor(MainEventBus mainEventBus,TaskStore taskStore,
													   PushNotificationSender pushSender,
													   QueueManager queueManager) {
		return new MainEventBusProcessor(mainEventBus, taskStore, pushSender, queueManager);
	}
	

	@Bean
	public RequestHandler requestHandler(AgentExecutor agentExecutor, TaskStore taskStore, QueueManager queueManager,
	                                     PushNotificationConfigStore pushConfigStore,
	                                     MainEventBusProcessor mainEventBusProcessor,
	                                     @Qualifier("a2aInternal") Executor executor) {
		return new DefaultRequestHandler(agentExecutor, taskStore, queueManager,
				pushConfigStore, mainEventBusProcessor,
				executor, executor);
	}

Spring Boot recognizes @PostConstruct (and @Inject), so DefaultRequestHandler.initConfig() and MainEventBusProcessor.start() will be executed in this case.

Then, test using the following request:

{
  "jsonrpc": "2.0",
  "id": "6e7bf51a-f364-42d7-a060-343da3cc4f43",
  "method": "SendMessage",
  "params": {
    "message": {
      "messageId": "messageId-1",
      "role": "ROLE_USER",
      "parts": [
        {
          "text": "Can you check systems?"
        }
      ]
    }
  }
}

Response 200 OK

Response Body:

{
  "error": null,
  "id": "6e7bf51a-f364-42d7-a060-343da3cc4f43",
  "jsonrpc": "2.0",
  "result": {
    "role": "ROLE_AGENT",
    "parts": [
      {
        "text": "Hello World",
        "metadata": null
      }
    ],
    "messageId": "d062faba-39e6-4ac6-b891-9e0ba1363a69",
    "contextId": "c2c16e07-dfad-40f1-958c-41d336d4363e",
    "taskId": "d38c2bc5-7491-4920-a290-93582d21a9e0",
    "referenceTaskIds": null,
    "metadata": null,
    "extensions": null
  }
}

A success result was returned.

Hopefully, these new improvements will be helpful to your revisions.

Thanks for what you did.

fix(server): cover direct request handler wiring

fix(server): preserve task ids for emitted messages

Everything is working fine. I'm closing this issue.

fix(server): start event bus processor for manual wiring

fix(server): cover direct request handler wiring

fix(server): start event bus processor for manual wiring

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[Help]: Could not find a Task/Message for 84ced8e6-3705-41c6-9158-f2b880463a32 #995

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[Help]: Could not find a Task/Message for 84ced8e6-3705-41c6-9158-f2b880463a32 #995

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guofengzh commented on Jul 26, 2026

guofengzh commented on Jul 30, 2026

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