Android Accessibility Service

The Android Accessibility Service is a system-level API that lets an app observe and interact with the UI of other applications on the device, exposing the hierarchical view tree (class names, text, bounds, clickability) and dispatching events such as focus changes, clicks, and text entry. It is the foundation for Android assistive technologies including TalkBack, Switch Access, Voice Access, and Select to Speak, and is increasingly used by tutoring, automation, and AI assistant apps to read screen structure. Because the service can read almost everything on screen, Google requires apps using it to declare a clear accessibility purpose - misuse for automation or data collection is a well-known policy grey area.