Expand description
Apple’s push service, for reaching a koan iOS app that iOS has suspended.
A linked app is reached over its WebSocket. iOS suspends an app in the background that is not playing, and the socket dies with it; a push is the supported way back. Two kinds: a background push that wakes the app for half a minute to link and take what waits for it in the outbox, and a notification for playback, which iOS will not let a suspended app start on its own: the person taps it, the app opens and plays.
Token auth: a JWT signed with the team’s .p8 key, reused for under an
hour as Apple asks. HTTP/2, which is all the gateway speaks.
A notification carries a link to its album’s cover, which the app’s notification service extension fetches and attaches. The extension holds no credentials, so the link authorises itself: an HMAC over one track id and an expiry, keyed by a secret that lives only in this process. It opens that one cover for a few minutes and nothing else.
Structs§
- Activity
State - What a Live Activity shows of the device it follows. The field names are
the app’s
RemoteActivity.ContentState, which decodes it. - Pusher
Enums§
Functions§
- payload
- The JSON a push carries. The command rides under
koan, beside Apple’saps, so the app can act on it without asking the server first. - pusher
- The server’s pusher, from the config it started with;
Nonewhen no key is configured, and pushes are simply not sent. - router
/push/cover/{track}/{expires}/{sig}: public, since the extension that fetches it has no login. Anything but a valid, unexpired link is a 404.