I have a question if a seller ask me to edit any item by API from his seller list can i retrieve a seller item and edit it, what will i need what i have to ask from the seller to edit his item does seller have any api keys through which an item can be revised by apis ??
Yes, what you're seeking can be done. The seller will of course need to authorize your use of the API on his/her listings. You'll use your own API keyset, and s/he will authorize by logging in to the application you provide which will generate a token that you'll maintain securely. But that's a super-quick overview. You have a lot to learn about how to use the Trading API to get to where you want to be. Perhaps start learning about the eBay API at the top: