The NX-API CLI is a web interface through which commands traditionally entered via the CLI, can be encoded using either XML or JSON, and transmitted via HTTP or a secure transport (HTTPS) to the device. The commands are executed on-box and responses are returned in either XML or JSON format.

The NX-API CLI can be characterized as an "encapsulated CLI" supporting both NX-OS commands and those available in bash. In contrast, NX-API REST interface provides a means through which device configurations can be manipulated via RESTful API calls. Both the NX-API CLI and NX-API REST are serviced by an nginx web server on the back end.