Classic Bluetooth | Platform Setup

Android

<!-- Android 12 (API 31) and above -->
<uses-permission android:name="android.permission.BLUETOOTH_SCAN"
                 android:usesPermissionFlags="neverForLocation" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
<!-- only if you call RequestDiscoverable -->
<uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE" />

<!-- Android 11 (API 30) and below -->
<uses-permission android:name="android.permission.BLUETOOTH" android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" android:maxSdkVersion="30" />

RequestAccess() asks for BLUETOOTH_SCAN and BLUETOOTH_CONNECT (or the legacy three) and returns NotSetup if any of them is missing from the manifest. RequestDiscoverable asks for BLUETOOTH_ADVERTISE itself, and throws BluetoothPermissionException if it isn’t granted.

neverForLocation keeps discovery free of a location prompt. Drop it only if you derive location from the results.

Windows

Unpackaged apps need nothing. Packaged (MSIX) apps declare the device capabilities:

<Capabilities>
  <DeviceCapability Name="bluetooth" />
  <DeviceCapability Name="radios" />
</Capabilities>

Pair uses Windows’ own pairing UI. RequestDiscoverable isn’t available: Windows only makes a PC discoverable while the Bluetooth settings page is open.

macOS

Shiny.Bluetooth targets macOS (AppKit), not Mac Catalyst.

<!-- Info.plist -->
<key>NSBluetoothAlwaysUsageDescription</key>
<string>Connects to your Bluetooth printer</string>

<!-- Entitlements.plist, when sandboxed -->
<key>com.apple.security.device.bluetooth</key>
<true/>

The .NET macOS SDK has no IOBluetooth binding, so Shiny drives IOBluetooth through the Objective-C runtime. IOBluetooth delivers every callback on the main run loop, so this works in an AppKit app (including Shiny’s macOS hosting), but not in a console app that never runs an NSApplication loop.

RequestDiscoverable isn’t available, and the secure flag on Connect/Listen is ignored, because IOBluetooth negotiates security itself.

Linux

Reference Shiny.Bluetooth.Linux and register with AddLinuxBluetooth(). It talks to BlueZ over D-Bus, so it needs:

• bluetoothd running, with the adapter at hci0 (the only adapter used)
• permission to talk to org.bluez on the system bus: root, or a member of the bluetooth group under the default D-Bus policy
• a BlueZ agent to answer PIN or confirmation requests during Pair. A desktop session has one. On a headless device, use bluetoothctl or pair once by hand. Without an agent, Pair returns false.

Every connection, in both directions, goes through BlueZ’s ProfileManager1. The library registers a Profile1 object for each service UUID. BlueZ does the SDP lookup, the RFCOMM connect or accept and the security checks, then hands the process the connected socket. Connect needs BlueZ to already know the device, either paired or seen by Discover, and throws BluetoothConnectionException saying so if it doesn’t.

RequestDiscoverable sets the adapter’s Discoverable and DiscoverableTimeout properties. If polkit refuses, it throws BluetoothPermissionException.

iOS, Mac Catalyst and tvOS

There is no target. On Apple’s mobile platforms classic Bluetooth is ExternalAccessory, which only reaches MFi-certified accessories with a protocol string Apple has approved for the app. Use BluetoothLE for cross-platform device communication that includes iOS.