Inter‑Agent Communication (A2A Bridge)

Why A2A?

• Inter‑operability. Lets agents written in Julia inter‑operate with agents hosted anywhere that speaks the open A2A (Agent‑to‑Agent) protocol.

• Zero client code. External users send a plain HTTP request; the bridge translates it to the agent’s webhook and streams back the result.

• Stateless scaling. All session state lives in the JuliaOS backend; the bridge is a thin, stateless proxy, so you can run as many uvicorn workers as you like behind a load‑balancer.

Core Components

Layer	Implementation	Notes
HTTP Edge	uvicorn + Starlette (starlette.io)	Lightweight ASGI server; hot reload at container restart.
Route Mounting	A2AStarletteApplication	At startup, the bridge discovers RUNNING agents and mounts /{agent_id}/a2a.
Executor	GenericExecutor	Parses text → JSON, invokes POST /agents/{id}/webhook, streams the last log line.
Backend API	JuliaOSConnection (Python SDK)	Auto‑generated client; same auth & RBAC rules as CLI/REST.

Request / Response Walk‑through

1. External caller posts (JSON) to http://<bridge>/<agent_id>/a2a.

2. GenericExecutor hands the payload to the agent’s webhook via httpx.AsyncClient python-httpx.org.

3. JuliaOS executes the chosen tool/strategy; each step is logged.

4. The bridge captures only the last log entry (convention: final answer) and streams it back as the A2A reply.