The service is available today to select users, Facebook says. It will start off in the US cities that Uber operates in, and then expand internationally. Facebook Messenger has 700 million users globally, as of June 2015.

The integration highlights a growing effort by messaging apps to drive online and offline purchases within their platforms. In Asia, WeChat, a messaging app with 600 million users, lets users order taxis, food, buy movie tickets, and make purchases in stores. Users had tied 200 million credit cards to WeChat’s payment service as of November 2015. In the US, Facebook Messenger and Snapchat added the ability to send money to friends over the last year.

“Facebook Messenger had already started to add businesses and brands into the Messenger experience and let users interact with those businesses,”Aunkur Arya, VP & GM, Mobile at Braintree told Quartz. “They haven’t directly added commerce, but they already started down this line and creating this new experience for business and consumers. This [new feature] is just a natural extension of that.”

Facebook Messenger head David Marcus, who was previously the president of PayPal, has been focusing on turning Messenger into a portal that lets consumers and businesses connect, interact, and, eventually, carry our transactions. The first step was opening up Facebook Messenger to developers—at the annual F8 conference, Messenger announced content integrations with companies including Giphy, and that businesses like Everlane would field customer service issues through Messenger.

Uber has been expanding its partnerships as well. The ride-sharing startup partnered with work chat app HipChat to let users call for an Uber within the app. The same functionality exists for Slack, another work chat app, though unofficially.

Ayra says the partnership between Uber and Facebook Messenger is “the best example” of using everyday interactions and conversations to drive commerce. “You have one super high-frequency use case, Uber, inside of another high-frequency app, Facebook Messenger. This partnership is the best example merging two experiences into one.”

📬 Sign up for the Daily Brief

Our free, fast, and fun briefing on the global economy, delivered every weekday morning.