This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
devices property gives direct access to all the Bluetooth devices discovered in the area surrounding the device's adapter.
var devices = instanceOfBluetoothAdapter.devices
Not part of any specification yet. It should be discussed as part of the W3C's System Applications Working Group.