First of all ...Hello everyone!

I am new to Zen-Cart and we have a new e-commerce website coming up that has a small list of automotive products that will be loaded into the cart store but we have an iFrame catalog from a vendor that they want an API fro the Zen-Cart so their products will wind up in the cart along with the other products for checkout. I don't exactly know what they want me to supply?
Thank you for your help on this....