Build me dropship automation tool

I am a drop shipper and I sell products on Amazon. Whatever I sell on amazon is then bought from ebay and shipped to the customer. 1-2 days later, the ebay seller puts up the tracking information and then I manually copy and paste that to my amazon order and finally mark it as shipped on amazon as well. I want to automate this process and I know that it is possible because ebay and amazon both offer API. I want you to build a tool that would automatically read new orders from Amazon and automatically place them on eBay. A couple days later (or as soon as the ebay seller puts up the tracking ID), the tool must also update that tracking ID on my amazon seller account and mark the item as shipped. This tool doesn't need to be fancy or anything, it just needs to work.