Action definition files
An action definition (.nwa) file is a text file that contains an XML fragment which represents the metadata needed by Nintex Workflow 2013 export (.nwp) file to associate the workflow activity, workflow action adapter, and configuration page for a custom workflow action, and to display information about the custom workflow action. The information in the action definition file is written to the Nintex Workflow configuration database when the custom workflow action is deployed.
For more information about creating action definition files for custom workflow actions, see Creating the action definition file.