ADK Beyond Its Own Tests: What Happens When Your Agent Answers a Client That Is Not ADK

to_a2a() turns an ADK agent into an A2A server in one line. That is genuinely the shortest path from an LlmAgent to something another vendor's agent can call, and it is the reason I started here.

Then I put that agent in a mesh where the callers are not ADK — a Strands agent on Bedrock AgentCore and a Microsoft Agent Framework agent on Azure Container Apps, all three given the same research brief, all three answering over A2A v1.0 to one coordinator on Cloud Run.

Everything below is what showed up on the Google side of that, and none of it is visible from a laptop.

The code: github.com/xbill9/multicloud-a2a-subagent.

The agent card advertises your bind address