Azure IoT Python: Configure MQTT over WebSockets Through a Proxy

In an application already using the Azure IoT Python SDK, choose the MQTT transport and its proxy options together. This configuration selects MQTT over WebSockets:

proxy = ProxyOptions(proxy_type='HTTP',
                     proxy_addr='203.0.113.10', proxy_port=8080)
client = IoTHubDeviceClient.create_from_connection_string(
    connection_string, websockets=True, proxy_options=proxy
)

The classes are from the SDK's documented interface. Supply the device connection string through the application's secret configuration and replace the example proxy endpoint. For a publicly reachable IoT Hub endpoint where public intermediaries are allowed, the HTTP proxy list offers candidates for the HTTP host and port; confirm the service permits the destination route. These are explicit SDK options; a browser's working proxy or a generic operating-system setting does not establish the device client's route.

Check the ProxyOptions reference for the selected proxy type. It distinguishes HTTP, SOCKS4 and SOCKS5 fields and documents type-specific username/password behavior, including limitations for HTTP. A field's presence does not promise every authentication mechanism.

The proxy account and device identity authorize different stages. A rejected intermediary exchange can stop the connection before the broker evaluates the device credential. Selecting WebSockets also leaves the proxy's destination and access restrictions in force.

Record the selected transport, destination and first failed stage. The SDK client, proxy implementation and permitted route must agree; neither a successful browser request nor a general claim that SOCKS carries every protocol supplies that compatibility.