[Bug]: Getting an error, trying to implement the Helloworld example

[kumaranpm]

What happened?

Trying to implement the HelloWorld example. On the server side, getting this error. Any clues?

\Lib\site-packages\a2a\server\apps\starlette_app.py", line 284, in _handle_get_agent_card
    self.agent_card.model_dump(mode='json', exclude_none=True)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'tuple' object has no attribute 'model_dump'  

Relevant log output

INFO:     127.0.0.1:65261 - "GET /.well-known/agent.json HTTP/1.1" 500 Internal Server Error
ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\uvicorn\protocols\http\httptools_impl.py", line 409, in run_asgi
    result = await app(  # type: ignore[func-returns-value]   
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^   
        self.scope, self.receive, self.send
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\uvicorn\middleware\proxy_headers.py", line 60, in __call__ 
    return await self.app(scope, receive, send)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\applications.py", line 112, in __call__
    await self.middleware_stack(scope, receive, send)
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\middleware\errors.py", line 187, in __call__     
    raise exc
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\middleware\errors.py", line 165, in __call__     
    await self.app(scope, receive, _send)
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\middleware\exceptions.py", line 62, in __call__  
    await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\_exception_handler.py", line 53, in wrapped_app  
    raise exc
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\_exception_handler.py", line 42, in wrapped_app  
    await app(scope, receive, sender)
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\routing.py", line 714, in __call__
    await self.middleware_stack(scope, receive, send)
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\routing.py", line 734, in app
    await route.handle(scope, receive, send)
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\routing.py", line 288, in handle
    await self.app(scope, receive, send)
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\routing.py", line 76, in app
    await wrap_app_handling_exceptions(app, request)(scope, receive, send)
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\_exception_handler.py", line 53, in wrapped_app  
    raise exc
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\_exception_handler.py", line 42, in wrapped_app  
    await app(scope, receive, sender)
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\starlette\routing.py", line 73, in app
    response = await f(request)
               ^^^^^^^^^^^^^^^^
  File "C:\Users\kumar\anaconda3\envs\mcpa2a_2\Lib\site-packages\a2a\server\apps\starlette_app.py", line 284, in _handle_get_agent_card
    self.agent_card.model_dump(mode='json', exclude_none=True)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'tuple' object has no attribute 'model_dump'

Code of Conduct

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[holtskinner]

I've not been able to reproduce this.

Are you following the tutorial listed here? https://google.github.io/A2A/tutorials/python/1-introduction/

[Linux2010]

You should list your execution commands, Python environment information, UV environment information, etc., to facilitate problem localization (in most cases, the failure to run "Hello World" is related to the local execution environment).