A2A Logging of context between orchestrator and assistants

[thebigcosinus]

Hi,

I'm trying a mutli agent architecture with an master/orchestrator and some assistants.

Is there a way to see what are the messages echnages between the master and the assistants ?

I've seen some data here in the logs strands.multiagent.a2a.executor |but want I'm looking for is the inforamtion send from the master agent to the asssistant.

Regards

[yonib05]

Hi @thebigcosinus, thanks for the question, and sorry it sat this long without a reply.

The logs you found in strands.multiagent.a2a.executor are the assistant's server side. What you actually want is the message the orchestrator sends, and that's easiest to capture on the orchestrator itself. Why? Because when the master calls an assistant through the A2A client tools, the outgoing message is just the tool input. A hook shows it directly:

from strands.hooks import BeforeToolCallEvent

def log_outgoing(event: BeforeToolCallEvent) -> None:
    print(f"tool: {event.tool_use['name']}, input: {event.tool_use['input']}")

orchestrator.add_hook(log_outgoing)

The matching AfterToolCallEvent gives you the assistant's reply as it comes back. Hook docs are here: hooks.

Two other angles. After a run, orchestrator.messages contains every toolUse block, which is exactly the payload sent to each assistant. And for production, the OpenTelemetry integration records tool spans with parameters and results on the orchestrator side while the assistants emit their own spans, so you get the whole exchange end to end: traces.