JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
You can probably integrate JotForm with an API by customizing the form's source codes and hosting it on your server. However, the integration may not be reliable because the form's action URL is still residing on our server, so it will be unaffected by the API codes.
Furthermore, customizing JotForm's source codes is a "do it at your own risk" activity. We cannot guarantee full form functionality when you customize the codes.
We have just released the beta version of JotForm API. Here are the docs:
If you need any help let us know.