Accessory Setup | Platform Setup

iOS

AccessorySetupKit needs iOS 18 or later. Every filter you pass to ShowPicker has to be declared in Info.plist, or the picker refuses the request and ShowPicker throws InvalidRequest.

<key>NSAccessorySetupSupports</key>
<array>
    <string>Bluetooth</string>
</array>

<!-- every AccessoryDiscoveryFilter.ServiceUuid -->
<key>NSAccessorySetupBluetoothServices</key>
<array>
    <string>6E400001-B5A3-F393-E0A9-E50E24DCCA9E</string>
</array>

<!-- when a filter sets CompanyIdentifier, also declare NSAccessorySetupBluetoothCompanyIdentifiers listing each one -->

<!-- every AccessoryDiscoveryFilter.NameSubstring, when you use them -->
<key>NSAccessorySetupBluetoothNames</key>
<array>
    <string>Shiny</string>
</array>

Skipping the Bluetooth prompt

Leave NSBluetoothAlwaysUsageDescription out of Info.plist, and never call IBleManager.Scan, and the app never shows the Bluetooth permission prompt. CoreBluetooth then only sees the accessories the user picked, which is all GetPeripheral needs.

If the app also has to scan for other devices, add NSBluetoothAlwaysUsageDescription back. The prompt then appears as it would without this package.

Product images

AccessoryPickerItem.ProductImage is an image name in the app bundle (as UIImage.FromBundle takes it) or a file path. Use a transparent PNG. Without one the sheet shows a generic Bluetooth symbol.

Android

CompanionDeviceManager is available from Android 8. Background presence needs Android 12.

<uses-feature android:name="android.software.companion_device_setup" android:required="false" />

<!-- GATT on Android 12+ still needs this runtime permission -->
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />

<!-- only if you call StartObservingPresence -->
<uses-permission android:name="android.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE" />

required="false" keeps the app installable on devices without the feature. On those, IsSupported is false.

The picker doesn’t replace BLUETOOTH_CONNECT: the association covers discovery, not the GATT connection. Request it before connecting, through Shiny.BluetoothLE’s access request.

ShinyCompanionDeviceService is declared by the package and merged into your manifest. You don’t add it yourself.

The picker’s result comes back as an activity result, so the host has to forward OnActivityResult to Shiny. MAUI hosting does this already. Native Android hosts derive their activity from ShinyAndroidActivity.

Falling back to a scan

Outside iOS and Android, AddAccessorySetup() registers only Bluetooth LE, and IsSupported is false on iOS 17 and older and on Android devices without companion_device_setup. Shared code can resolve the manager as optional and scan when it isn’t there:

public class PairingViewModel(IBleManager ble, IAccessorySetupManager? setup = null)
{
    public async Task<IPeripheral?> FindSensor()
    {
        if (setup?.IsSupported == true)
        {
            var accessory = await setup.ShowPicker(new AccessoryPickerItem(
                "Shiny Sensor",
                new AccessoryDiscoveryFilter { ServiceUuid = "6E400001-B5A3-F393-E0A9-E50E24DCCA9E" }
            ));
            return accessory == null ? null : ble.GetPeripheral(accessory);
        }

        // no system picker - request access and scan as usual
        await ble.RequestAccessAsync();
        // ble.Scan(new ScanConfig("6E400001-B5A3-F393-E0A9-E50E24DCCA9E")) ...
        return null;
    }
}

The scan path needs the usual BluetoothLE platform setup, including NSBluetoothAlwaysUsageDescription on iOS.