The bridge is deliberately thin: register a URL, send a message, poll or stream the result, cancel if it drags. That thinness is the point — nothing here interprets what the far side does, so the behaviour you get is the remote agent's rather than the bridge's. Sending and streaming are separate tools rather than one tool with a flag, so how the reply arrives is decided at call time.
A bridge between an MCP client and A2A agents, seven tools for registering agents and exchanging messages and tasks with them.
- Agents registered by URL, listed back, and unregistered when they retire
- Messages sent to a named agent, carrying a session id so an exchange can be more than one turn
- The same message streamed instead, for answers long enough that waiting for the whole of it is the wrong shape
- A task's result collected afterwards by task id, with as much of its history as you ask for
- A running task cancelled on the agent that is running it
Uv with a Python interpreter available — UV_PYTHON selects which one — and at least one reachable A2A agent whose URL you can register. Agents are addressed by that URL, so nothing works until one is running. Apache-2.0.
One command — uvx a2a-mcp-server