The Android Developers account called AppFunctions "officially in beta" from the Android Dev Summit stage. The Jetpack library it points you to is 1.0.0-alpha10 .

That gap is the whole story.

i opened the docs page to check what i would actually be installing. The banner at the top still calls AppFunctions an experimental preview, subject to change. The page was last updated a week before the summit.

So the announcement walked one step ahead of the code. Not by much. Just enough that the tweet and the artifact disagree.

Here is the short version. Your app becomes a local MCP server, and every annotated Kotlin function becomes a tool an agent can call.

Not a remote server. No network hop. The function runs inside your app, on the phone, in your own process, against your own local state.

Which sounds great until you ask who is allowed to call it, and what they read when they decide.

i spent an evening on this and came out more interested than i expected. Also more annoyed.…