How to pass in custom price from remote add to cart?

I have a 1 page web app to build a customized product, and I want to add it to the cart of a current zencart installation on the same domain. I have it mostly figured out, and tested by manually copy/pasting security token (will figure out how to automate next).

My main question is, what attribute can I pass via the html form to set the price of the product? There are thousands of price possibilities, so I can't manually create them.

For example, I've done this on another cart software with this <input type="hidden" id="price" name="price" value="[price injected dynamically]">.

For reference, here is my custom product builder with the remote add to cart button: https://www.chair-mat-office.com/custom-mat-builder/

You sir will need to inject the price into the product price, and most certainly make a product to handle this fancy new price.

Can you send more than just the price?

It would be handy for the customer to reference the actual product they purchase...

Which leads me to believing it's far wiser to use your code to 'make' a product with attributes when the customer completes the product builder.

I currently have a custom product, so they know they ordered a "custom mat". It would be nice to pass in the price and description. Do you know the html input name attributes to do that?