Exposing Confetti sessions and bookmarks to AI agents using Android AppFunctions

[versions]
...
androidx-appfunctions = "1.0.0-beta01"

[libraries]
...
androidx-appfunctions = { module = "androidx.appfunctions:appfunctions", version.ref = "androidx-appfunctions" }
androidx-appfunctions-compiler = { module = "androidx.appfunctions:appfunctions-compiler", version.ref = "androidx-appfunctions" }

implementation(libs.androidx.appfunctions)
ksp(libs.androidx.appfunctions.compiler)

@RequiresApi(36)
@AppFunctionServiceEntryPoint(
    serviceName = "ConfettiAppFunctionService",
    appFunctionXmlFileName = "confetti_app_function_service",
)
abstract class BaseConfettiAppFunctionService : AppFunctionService(), KoinComponent {
    private val repository: ConfettiRepository by inject()
    private val appSettings: AppSettings by inject()
    private val authentication: Authentication by inject()

    /**
     * Lists every session in the currently selected conference.
     *
     * @return All sessions with their ID, title, description and start/end times.
     */
    @AppFunctionDeclaration(isDescribedByKDoc = true)
    suspend fun listSessions(): List<SessionResponse> = withContext(Dispatchers.IO) {
        val conference = requireConference()
        val user = authentication.currentUser.value
        val response = repository.sessions(conference, user?.uid, user, FetchPolicy.CacheFirst)
        response.data?.sessions?.nodes?.map { it.sessionDetails.toResponse() } ?: emptyList()
    }

    /**
     * Bookmarks a session in the currently selected conference. Requires the user to be
     * signed in to Confetti.
     *
     * @param sessionId ID of the session to bookmark, as returned in [SessionResponse.id].
     * @return true if the bookmark was saved.
     */
    @AppFunctionDeclaration(isDescribedByKDoc = true)
    suspend fun addBookmark(sessionId: String): Boolean = withContext(Dispatchers.IO) {
        val conference = requireConference()
        val user = requireSignedInUser()
        repository.addBookmark(conference, user.uid, user, sessionId)
    }

    // getConference, removeBookmark and helper functions omitted
    ...
}

/** A session (talk or workshop) in a conference. */
@AppFunctionSerializable(isDescribedByKDoc = true)
data class SessionResponse(
    /** Unique ID of the session, used to add or remove a bookmark. */
    val id: String,
    /** Title of the session. */
    val title: String,
    /** Abstract describing the session content, if provided. */
    val description: String?,
    /** Start time in the conference's local time zone. */
    val startsAt: LocalDateTime,
    /** End time in the conference's local time zone. */
    val endsAt: LocalDateTime,
)

<service
    android:name="dev.johnoreilly.confetti.functions.ConfettiAppFunctionService"
    android:permission="android.permission.BIND_APP_FUNCTION_SERVICE"
    android:exported="true"
    tools:targetApi="36">
    <property
        android:name="android.app.appfunctions.schema"
        android:value="app_functions_schema.xsd" />
    <property
        android:name="android.app.appfunctions.v2"
        android:value="confetti_app_function_service.xml" />
    <intent-filter>
        <action android:name="android.app.appfunctions.AppFunctionService" />
    </intent-filter>
</service>
<property
    android:name="android.app.appfunctions.app_metadata"
    android:resource="@xml/app_metadata" />

<AppFunctionAppMetadata xmlns:appfn="http://schemas.android.com/apk/androidx.appfunctions"
    appfn:instructions="Confetti is a conference schedule app: it lists the sessions of the conference the user has selected and manages the user's session bookmarks.
Operational patterns:
- 'listSessions' returns the session IDs that 'addBookmark' and 'removeBookmark' take.
- All functions act on the currently selected conference, which 'getConference' returns.
Constraints:
- A conference must already be selected in the app; switching conference is not supported.
- Adding or removing bookmarks requires the user to be signed in to Confetti." />

adb shell cmd app_function list-app-functions --package dev.johnoreilly.confetti

adb shell "cmd app_function execute-app-function --package dev.johnoreilly.confetti \
  --function 'dev.johnoreilly.confetti.functions.BaseConfettiAppFunctionService#getConference' \
  --parameters '{}' --brief-yaml"