WebSocket Hub for 100 ESP32s

I have roughly one hundred ESP32 boards on the same LAN. A single Raspberry Pi will sit in the middle, behaving as a master gateway: it exchanges messages with each ESP32 over the local router and holds one persistent WebSocket link to my remote web server. I need the full bridge—ESP32 firmware and Pi-side service—written, tested and ready to run as soon as possible.

Here is what I expect to receive:

• Raspberry Pi service (Python, Node-JS or similar) that
– discovers or registers ESP32 units,
– maintains simultaneous connections, queues messages and forwards them over the WebSocket tunnel,
– handles reconnects, heart-beats and basic security (token or key-based).

• ESP32 firmware (Arduino IDE or ESP-IDF) able to
– connect via Wi-Fi to the router,
– subscribe to commands from the Pi and publish its own status/data,
– keep memory and bandwidth light enough to scale to ~100 devices.

• Simple config file or script so I can point the Pi at a different web-server URL or change Wi-Fi credentials without recompiling.

Acceptance will be a brief live demo or video showing at least ten boards chatting through the Pi to a test WebSocket echo on the server, plus all source code and setup notes in a Git repo or ZIP.

If you have done high-volume ESP32 deployments or written load-balanced WebSocket gateways before, you’ll finish this quickly—which is perfect, because I need it running ASAP.