Doorbell is a very simple Vue.js 3 progressive web application that sends a post request to a webhook. That's literally all it does.
Communal door entry is a pain. You need to get special keyfobs and issue them out, usually at a charge from the building management company.
This simple little web-app runs on a unique URL (kind of like a token URL) that can be shared with anyone. With that, they can access the page and send a request to the webhook.
The intercom in the flat has a SwitchBot stuck to it which presses the entry button when activated. The SwitchBot is connected to Home Assistant over bluetooth. An automation is set up on Home Assistant to listen for a webhook and then activate the SwitchBot.
A user rings the intercom then opens the page on their phone, in turn activating the SwitchBot which presses the entry button.
Yes, its quite a long-winded and hacky solution but its the easiest method without pulling things apart.
The web-app requires two environment variables to be set:
VITE_SECRET_PATHis a unique URL which acts like a secret token. It must be prepended with/.VITE_WEBHOOKis the webhook URL, in my case it is a Home Assistant webhook.