My first guess would be that you might have a syntax error in the API file.
Try running it through a JavaScript validator like
http://www.jslint.com/ to see if it is properly compiling.
If this is the case, the existing calls would appear in Visual Logic but if it is unable to parse/execute your API file, it will not show the functions to add additional calls or add your new functions.
If the script validates, let me know and we can try to debug further.
#DashBoard