Paypal web payments standard - Refunds. Can they be done via the Api?

I've been pulling my hair out going through the Paypal documentation maze. My question is开发者_开发问答 simple. Is it possible to instigate a refund via an API call with web payments standard?

I know you can with the pro version as I've found various bits of documentation dotted around the place. I also found This bit of info from Paypal but it doesn't seem to mention any version requirements or a url to send the call to.

Many thanks!

Yes. RefundTransaction can also process refunds from Standard or Express Checkout transactions. It won't work for Payflow Link or Pro however.