Communication between a host device and an accessory via an intermediate device

A host device and an accessory exchange information (e.g., commands and data) via an intermediate device. The host device and accessory can each connect to the intermediate device through a direct wired path and can exchange commands and data with the intermediate device. The host device and the accessory can also "tunnel" information to each other through the intermediate device, by packaging the tunneled information as a payload of a command recognizable by the intermediate device; the intermediate device can repackage and forward the payload. In some embodiments, the tunneled information relates to configuring a wireless link (e.g., a Bluetooth pairing) between the host device and the accessory.