Based on the A2A Protocol blog, we learned about the basic concepts of A2A Protocol and how to develop using the A2A Protocol Python SDK.

This article will introduce how to use A2A Protocol Validator to verify A2A Protocol and visualize AgentCard for convenient debugging:

• Verify whether a given domain supports A2A Protocol
• Visualize AgentCard

For publicly deployed A2A Agents, you can directly input the domain for verification.

How to Verify Locally Running A2A Agent?

• Prepare Agent

git clone https://github.com/sing1ee/a2a-python-currency.git
cd a2a-python-currency
uv run python main.py

Output:

Installed 27 packages in 33ms
INFO:     Started server process [61455]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
INFO:     Uvicorn running on http://localhost:10000 (Press CTRL+C to quit)

This way, the Currency Agent is running locally, accessible on port 10000.

• Map local Agent service - Using Cloudflare Zero Trust Refer to the documentation for installation. My environment is Mac

brew install cloudflared

• Start Zero Trust proxy

cloudflared tunnel --url localhost:10000

Output:

+--------------------------------------------------------------------------------------------+
2025-06-03T09:03:02Z INF |  Your quick Tunnel has been created! Visit it at (it may take some time to be reachable):  |
2025-06-03T09:03:02Z INF |  https://sheriff-honor-undefined-relate.trycloudflare.com                                  |
2025-06-03T09:03:02Z INF +--------------------------------------------------------------------------------------------+

https://sheriff-honor-undefined-relate.trycloudflare.com is the temporary domain that can access our local Agent service.

Open A2A Protocol Validator

Open A2A Protocol Validator, input the above domain, and you can verify whether the domain supports A2A Protocol.

Through these steps, you can quickly debug. We will launch an A2A online client in the future to make execution more convenient.