atsign-foundation

Use this skill when a developer is building a Dart or Flutter app that depends on at_client or at_client_flutter from pub.dev, stores or shares data via the Atsign Protocol, needs onboarding (CRAM new-atSign, atKeys file, keychain, APKAM) or APKAM enrollment, or asks about AtCollection<T>, CItem<T>, Query<T>, sub-collections, event streams, read receipts, wherePath typed predicates, or watchWithTree deep hierarchies. Also use when the developer asks how to send or receive notifications via NotificationService, which pub.dev packages to add, how to unit-test without a live atServer, or whether to use AtCollection vs notifications+SQLite. Warns against deprecated AtCollectionModel, at_common_flutter, at_backupkey_flutter, at_invitation_flutter, at_sync_ui_flutter, and at_theme_flutter.