http://home.wavecable.com/~edgarmusgrove/index.html#UnattendedAudacity
This is not really intended for the user who is unfamiliar with the Audacity source code and C++ programming! When you run this app from the CLI there will be NO GUI you will have to watch for the command prompt to return to know it is finished. It is really intended for unattended batch processing (I set it running in a batch process with hundreds of file when I go to bed and all is finished in the AM).
If you have a specific need to perform the same effect on large numbers of files, give me some details and I will craft a specific version specifically for you (I will need to know EXACTLY which effects are in your Audacity executable directory’s Plug-ins folder.