Serving a local model from a Raspberry Pi: one process for browsers (SSE) and devices (MQTT)

You have a small box — a Raspberry Pi, a Jetson, a cheap ARM VM — running a local model. Two kinds of traffic want in:

People (browser tabs, curl, httpx scripts) call an HTTP endpoint and want the answer streamed token by token, not after the last token.

Devices (sensors, cameras, controllers) speak MQTT. They report telemetry and drop batch jobs.

The conventional stack for that is three or four daemons: an web application server, a reverse proxy in front of it for HTTP/2, a separate MQTT broker, plus the glue that keeps them coordinated. On an edge box, every extra part is another thing to provision — and on ARM or RISC-V, potentially another native dependency to cross-compile.

I've been building BlackBull, a pure-Python ASGI framework whose protocol stack (HTTP/1.1, HTTP/2, WebSocket, gRPC, and an MQTT 5 broker) is all Python, all one process. Here is the whole edge-serving surface: