I'm using the (new) c5 8 Form block, which obviously saves submissions to the database. Are there any API calls that can be used to retrieve the submitted data subsequently?

I know the info is available from the dashboard, but I need to automate something based on the form data.

The normal solution would be to redirect on form submission to a c5 page on which I could use $this->post(...) in the controller to extract the fields. However, I'm using an external service (fitbit.com), so I can't necessarily transfer the flow of control directly, meaning that the post variables may no longer be available.

I could try to reverse-engineer the c5 database and query the data out of it, but that would seem like an inadequate level of abstraction. I'd rather go via the c5 API, if it provides what I seek.

I could intercept the form fields and save them myself, but this would mean there'd be TWO copies of the data in the database.

I've searched the API doco to try to find what I need, but haven't come up with anything. Pointers appeciated!