In a Cisco NX-OS environment, Ansible requires the NX-API to be enabled for HTTP/HTTPS protocol communication. NX-API is a REST-like API for NX-OS, providing a method for external applications to access the switch over HTTP/HTTPS, allowing for both CLI and simple object-based programming. This is necessary for Ansible to manage the device and execute automation tasks over these protocols.
References: Cisco's official documentation on NX-API and Ansible's documentation for Cisco NX-OS support.