Agent published using to_a2a and deployed to Google Cloud Run mandatorily adds port to the URL in Agent Card

[ameya-sap]

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Describe the bug
Agent published using to_a2a and deployed to Google Cloud Run mandatorily adds port to the URL in Agent Card, which breaks calling it from A2AClient

To Reproduce
Steps to reproduce the behavior:

1. Create a simple agent and expose by using the to_a2a() function.
2. Deploy it to cloud run. Once deployed you will see that the URL in Agent card is pointing to localhost:8000
3. Now, redeploy it by modifying URL to include cloud run service host, example: a2a_app = to_a2a(root_agent, host="...cloud run service host...")
4. Once deployed check the Agent card from cloud run, you will notice that the URL in the card will be "url": "http://...cloud run service host..:8000",
5. This URL will be used by "@a2a-js/sdk/client" or any other client once integrated. But cloud run service does not accept port and the client would fail with A2A Client Communication Error

Expected behavior
to_a2a() function should not mandate port while constructing agent card URL. Below code in agent_to_a2y.py should be corrected

[seanzhou1023]

discussed offline. port is necessary, default port for http is 80 and https is 443 respectively. We just need to add a protocol parameter to to_a2a.

[ameya-sap]

Thanks you for addressing this!

[vladkol]

This may be more an a2a issue rather than ADK: a2aproject/a2a-python#398