A new Automation Guide has been published by VMware to help customers to Automate the Virtual Networking using NSX APIs.
VMware NSX provides a RESTful API service via NSX Manager that can be consumed in several ways. The NSX REST API can be consumed directly via a tool/library such as cURL or a REST Client like Postman, via multiple popular programming languages, and via orchestration cloud management tools. Popular programming languages such as Python, PowerShell, Perl, Go, and Java have REST client libraries which can easily be utilized to consume the NSX REST API. This means that elaborate workflows and complete systems/portals can be created to provide custom automation, management, and monitoring capabilities.
For More details and download the guide on API Guide