@callback on_pass_added(serial_number :: String.t(), platform(), event_meta()) :: any()

Fires when a pass is added to a user's wallet.

• Apple: when a device registers for push notifications for this pass.
• Google: when a save callback is received from Google Wallet.

meta:

• Apple: %{device_library_id: String.t(), push_token: String.t()}
• Google: %{object_id: String.t(), class_id: String.t(), nonce: String.t(), exp_time_millis: integer()}

@callback on_pass_fetched(serial_number :: String.t(), platform(), event_meta()) :: any()

Fires when an Apple device fetches the latest version of a pass. This is high-volume — iOS may fetch the pass several times per day per device. Treat as informational; do not write a row per fetch to a consumer DB without rate-limiting.

Google does not have an analogue (Google serves pass updates itself).

meta:

• Apple: %{}

@callback on_pass_removed(serial_number :: String.t(), platform(), event_meta()) :: any()

Fires when a pass is removed.

• Google: unambiguous — the user removed the pass from their wallet.
• Apple: ambiguous. This event fires on any device unregister, which includes iOS push-token rotation, app uninstall, the user disabling notifications for the pass, or genuine pass removal. There is no on-device signal to disambiguate. Treat the Apple variant as "this device is no longer reachable for push," not as a definitive removal signal. For an authoritative wallet-presence check, use WalletPasses.wallet_presence/1 (which reports both platforms separately) or rely on Google's del.

meta:

• Apple: %{device_library_id: String.t()}
• Google: %{object_id: String.t(), class_id: String.t(), nonce: String.t(), exp_time_millis: integer()}