How to build a simple GUI for some basic transformation tasks (instead usage of spoon

Hello,

my name is Andrej Krywcun, a developer from Germany with preference in Javascript and PL/SQL.
I am currently evaluating KETTLE (so I am quite a bloody rookie, so apologies in advance for some may stupid question in the eye of an experienced KETTLE pro ^^) and one task I have to cover is the following:

I just want to to quite simple transformations, so from CSV to a table and from table to CSV with some evaluation in between.
For that I want to create a simple entry form, where you just have a list of source and target fields and click the connection between them.
The execution of the transformation shall be done - of course - by KETTLE.

I have created a DB repository and had a look on the tables, sounds quite self explaining and probably I would be able to insert/update above entered data.
But doing it wiithout API calls you may be f*cked up whenever there is a new release which brings changes in the repository.

So my question is:

Did anybody made up his mind on a similar task? Is there a maybe a tool where you can create an alternativ GUI for simple tasks like described?

Or maybe the API offers calls to write and read specific data which gives the possiblity to build up a own GUI ?!

THX alot in advance for you help,

Best regards,

Andrej