What is the API for receipt validation on server for Mac App Store apps. Is it same as iOS App store? is there any documentation link?

There are a few differences as noted here:

https://developer.apple.com/library/archive/releasenotes/General/ValidateAppStoreReceipt/Chapters/ValidateLocally.html#//apple_ref/doc/uid/TP40010573-CH1-SW2

That is for receipt validation inside the app itself. I am talking about server-side receipt validation.

At the bottom of the page is a "Next" button - tap that for the full document.

If you want to know about earlier OS versions you might consult this site:

h ttps:// w ww.objc.io/issues/17-security/receipt-validation/

(To access this URL you need to modify what is listed here. You do that by deleting the spaces in the URL.)