Facebook first began testing a “Buy” button within the News Feed in July, and payments startup Stripe has been tasked with powering the technology, Re/code has learned. The “Buy” button, which allows Facebook users to purchase goods that are featured in ads or posts on the social network, is still in its test phase, but multiple sources said Stripe’s technology was supporting the button. A Facebook spokesperson confirmed Thursday that Stripe is the sole Facebook payments partner behind the test. A Stripe spokesperson confirmed the company’s partnership with Facebook. This is noteworthy given that Facebook has other payments partners on different features, including PayPal’s mobile payments unit Braintree. It’s also not the first time Facebook and Stripe have worked together. Facebook partnered with Stripe last year on a separate project that enables Facebook users to autofill their payment information from Facebook when using third-party apps (Braintree was also a partner).