Getting Your SMS Apps Ready for Android 4.4 KitKat
Article Summary
Scott Main and David Braun from Android just changed the rules for SMS apps. If you're using hidden APIs, your messaging app will silently fail on KitKat.
Android 4.4 KitKat introduces a fundamental shift in how SMS apps work by making hidden APIs public and adding a default SMS app concept. This official Android Developers Blog post explains what developers must do to keep their messaging apps functional when the update rolls out.
Key Takeaways
- Only the default SMS app can write to SMS Provider on Android 4.4
- Apps need four specific manifest components to qualify as default SMS app
- Non-default apps can still send SMS but lose MMS and Provider write access
- Backup apps must temporarily become default, restore messages, then switch back
- Apps using hidden SMS APIs will silently fail without proper updates
Messaging apps must implement specific broadcast receivers, activities, and services in their manifest to remain functional on Android 4.4, or they'll lose the ability to write messages to the system.
About This Article
Developers building SMS apps had to deal with fragmentation across different Android versions. The APIs they relied on were hidden and could change or disappear without notice, which meant apps risked breaking on new devices or after platform updates.
Google's Android team made the SMS APIs public and introduced a default SMS app setting that users could choose in system settings. This gave developers a stable, supported API they could actually rely on for building messaging applications.
Developers can now implement four manifest components to keep their apps working. They need broadcast receivers for SMS_DELIVER_ACTION and WAP_PUSH_DELIVER_ACTION, an activity for ACTION_SENDTO, and a service for ACTION_RESPOND_VIA_MESSAGE. With these in place, their apps can write to the SMS Provider on Android 4.4 and later.