Prestashop Module Create urgent

Hello Dear. I have already developed a prestashop base website. another side i have also online pos software which developed in dot net platform. my pos is running in my physical store and its complete load with my current products stock. very recent i got prestashop website which i use for online sale . now i want to develop a module which connected prestashop stock and pos stock . let me clear it. my pos will be main for stock. i always update all of my stock in pos. you have to develop a module which connected with prestashop and pos . and its always update stock from pos to prestashop stock. when someone order in prestashop it will automatically take that product from pos stock . and if in pos any product is out of stock it should be show in website same. from pos i will give you api key for access with the permission or any level you need to marge stock. but i want to full automated that i just update stock in pos and it work for both.