Bidirectional (bidi) extension techniques for USB and/or other similar busses/connections are described in which an interface is provided to enable bidirectional communication with connected devices. The interface may be implemented as an operating system component to handle bidi communication for devices from multiple different independent hardware vendors (IHVs). Device drivers for different devices can be configured to include extension files in accordance with an established schema for bidi communication. The extension files describe supported bidi attributes, capabilities of the device, and how to make calls into the device. The interface operates to detect the extension files and set-up a corresponding device for bidi communication. Applications then interact through the interface to access, retrieve, and set configuration and status data for connected devices. The use of extension files enable creation of architecture independent devices drivers that can be used across different platforms with substantially no changes.