• Big Mac sauce is now available for 50 cents à la carte at McDonald's.
  • The famous sauce can only be ordered for a limited time exclusively on the app.
  • According to the McDonald's app, the offer is only available through May 10.

Whether you're a longtime fan of the iconic Big Mac sandwich or curious to taste its signature sauce, Big Mac sauce is now available à la carte at McDonald's.

Customers can order a dipping cup of the special sauce for 50 cents to accompany french fries or nuggets, but don't expect to ask for it at counter. According to McDonald's, you'll have to order exclusively through the restaurant's app to get your hands on the sauce, which comes in blue and white packaging inspired by an early Big Mac wrapper.

The sauce, which first began selling yesterday, is available at participating locations for a limited time only. 

"Mac sauce. Special sauce. Secret sauce," an April announcement read, per NBC Chicago. "Whatever you call it, fans have been asking for an extra side of our famous Big Mac sauce for years. And now, it's finally getting its moment in the spotlight on our menu."

McDonald's fans only have about 10 days to capitalize off the offer, as the app states that the sauce is only available through May 10.