Develop PHP to list inventory on Etsy

We are transitioning from codeigniter to pure php and we have PHP code that will list items on Etsy. There are 3 tasks that we need completed: 1. List a single item on Etsy - update the existing code to use Pure PHP and also use the item SKU (currently not all items are posted to Etsy with the SKU). 2. List all items that are part of the same group. Code is done with Codigniter and we need to port to pure PHP. 3. Update the script that pulls orders from Etsy into our database. Code is done with Codeigniter but it needs to be updated to Pure PHP and also needs a bug fix to ensure duplicate orders are not replicated in our database.