A practical first look at Google's new Jetpack API for exposing on-device app capabilities as tools an agent like Gemini can call Introduction Google just shipped the first public docs and the first usable alpha of AppFunctions — a Jetpack library paired with a new Android platform API that turns parts of your app into tools that AI agents can discover and execute. If you have ever used the Model Context Protocol (MCP) on the server side, AppFunctions is the Android-native equivalent: same idea, but the tool lives inside your app and runs locally on the device. It helps to be precise about what is actually new here, because the capability is not — its universality is. Until now, getting an assistant to act inside an app on your behalf was overwhelmingly a first-party affair: you could ask Google Assistant to add an event to Google Calendar, Bixby to create one in Samsung's calendar, or Siri to do the same on Apple's — each assistant wired tightly to its own vendor's apps.…