Serving & Mocking

serve spins up a local, A2A-compliant mock agent for testing and development. It lets you exercise the full discover → send → get loop without a real agent.

a2acli serve --echo --port 9001

Point another terminal at it with --service-url http://localhost:9001 (which is also the default), then run discover and send against it.

Flags

Flag	Default	Description
--echo	—	Echo mode: return the user’s message as the response
--port	9001	Listen port
--host	127.0.0.1	Bind address
--exec	—	Exec mode — not yet supported
--proxy	—	Proxy mode — not yet supported

Only echo mode works today

--echo is the only working mock mode. The --exec and --proxy flags are present but not yet supported — they are accepted on the command line but do not yet provide those modes.

Related

• Discovery & Identity — inspect the card your mock server advertises.
• Messaging & Tasks — send messages to the running mock.