This is a simple websocket server providing heartrate data in plain text. You're viewing the silly website built-in! :3
This might not be always available or accurate as this depends on my computer running and being connected to my watch over BLE.
If you want to connect to the websocket, it's available at the root of this URL.
It just sends the number as plaintext, ranging from 0-255.
No JSON or anything else.
From a terminal I recommend websocat.
This is open source, and works with any device supporting heart-rate data over BLE! I personally use a PineTime running InfiniTime. View the source code on GitHub!