A resident at the University of Washington (UW) has developed a unique project to count the number of people entering and exiting the UPL's doors. The project, which uses Home Assistant and Raspberry Pi, provides total access point isolation for security reasons. To retrieve the door status, the developer created an Express web server that proxies requests with a bearer token, ensuring only authorized users can access the information.

Source: https://www.amoses.dev/blog/upl-people-counter/