Branch, the deep-linking startup backed by Andy Rubin’s Playground Ventures, will enter the unicorn club with an upcoming funding round.

The four-year-old company, which helps brands create links between websites and mobile apps, has authorized the sale of $129 million in Series D shares, according to sources and confirmed by PitchBook, which tracks venture capital deals. The infusion of capital values the company at roughly $1 billion.

In an e-mail this morning, Branch CEO Alex Austin declined to comment.

The Redwood City-based startup closed a $60 million Series C led by Playground in April 2017, bringing its total equity raised to $113 million. It’s also backed by NEA, Pear Ventures, Cowboy Ventures and Madrona Ventures. Rubin, for his part, is a co-founder of Android, as well as the founder of Essential, a smartphone company that, though highly valued, has had less success.

Branch’s deep-linking platform helps brands drive app growth, conversions, user engagement and retention.

Deep links are links that take you to a specific piece of web content, rather than a website’s homepage. This, for example, is a deep link. This is not.

Deep links are used to connect web or e-mail content with apps. That way, when you’re doing some online shopping using your phone and you click on a link to an item on Jet.com, you’re taken to the Jet app installed on your phone, instead of Jet’s desktop site, which would provide a much poorer mobile experience.

Branch supports 40,000 apps with roughly 3 billion monthly users. The company counts Airbnb, Amazon, Bing, Pinterest, Reddit, Slack, Tinder and several others as customers.

Following its previous round of venture capital funding, Austin told TechCrunch that the company had seen “tremendous growth” ahead of the raise.

“[We] have been fortunate enough to become the clear market leader,” he said. “There’s so much more we can accomplish in deep linking and this money will be used to fund Branch’s continued platform growth.”