PowerShell Reference
Nintex provides PowerShell extension that can also help with managing and deploying the forms.
Note: SharePoint Subscription Edition does not support the standard Nintex Workflow cmdlets. You may see the error The term 'X' is not recognized as the name of a cmdlet, function, script file, or operable program. If you want to use these cmdlets in SharePoint Subscription Edition, see Invoke cmdlets in SharePoint Subscription Edition.
Nintex Forms 2013 SDK Reference
Add a Custom Inline Function with SharePoint 2013 Management Shell