Magic Switch Message

The Magic Switch Message is an Apple Watch-specific message sent when a user is wearing an Apple Watch that has lost its connection to its paired iPhone while its screen is on.

This message type was first mentioned in Handoff All Your Privacy — A Review of Apple's Bluetooth Low Energy Continuity Protocol by Martin et al., but more thoroughly described by Guillaume Celosia and Mathieu Cunche in Discontinued Privacy: Personal Data Leaks in Apple Bluetooth-Low-Energy Continuity Protocols.

Magic Switch Message (btcommon.apple.type == 0x0b)

Field Name	Info	Example	Length	Type	Notes
btcommon.apple.magicswitch.data	Data	c4b5	2	Bytes	Not sure what this is
btcommon.apple.magicswitch.confidence	Confidence on Wrist	On Wirst (0x3f)	1	UINT8

The message fields, observed values and their meaning:

• Type: 1 byte, 0x0B -- indicates an Magic Switch message
• Length: 1 byte, 0x03 -- number of bytes in the message payload
• Data: 2 bytes
• Confidence: 1 byte