Twitter is testing a buy button that will enable users to discover and buy products directly from tweets on the social network.

Testing is initially limited to a small group of US users, and enable brands advertising on the site and mobile app to integrate a Buy button into promoted tweets.

Rumours of a buy button function arose earlier this year when a tweet by shopping platform Fancy was spotted with a Buy button that caused a checkout page to open up within the Twitter mobile app, but at the time, neither Twitter nor Fancy were willing to confirm that tests were taking place. However, Fancy was one of the brands announced by Twitter as taking part in the tests today, along with Gumroad, Musictoday and Stripe.

Pressing on the Buy button opens up additional product details, and prompts the user to enter shipping and payment information before the order is sent to the merchant for delivery. Twitter claim that shipping and payment data is stored in encrypted mode, and will be remembered so users do not have to re-enter with each transaction.

The test will expand to include a number of artists, brands and nonprofit organisations over the next few weeks, including charities such as GLAAD, (RED) and The Nature Conservancy, and musical artists including Eminem, Wiz Khalifa, Paramore and Pharrell.