このタンスが動いてるサーバでSubwayTooterのアプリサーバ(プッシュ中継サーバ)も動かしてるけど、今のところ過負荷にはなってないよ

@kaniini Each web browser provides redirection server for receiving push event, then web app frontend can use it as callback url for push subscription for free.

@kaniini For redirect events to the mobile devices on the Mastodon's old-style stream API, the mobile app had to send the user's access token to the app server and keep the WebSocket streaming. It's not secure and light weight.
With the new push subscription API, the load on the app server is very light than old style, also subscription itself can do from the mobile app, no need to send access token from device to app server.

@kaniini Hi, I'm dev of Subway Tooter.
How about the idea just provide a WebHook style push subscription API compatible with the WebPush standard.
We can FCM and APN for free for sending events from app server to device (although it is not OSS).
Also of course the push subscription API can be used for other purposes.