Twilio, a California-based cloud communication company that enables customers to use standard web languages to build voice, VoIP, and SMS apps via a web API, has closed its acquisition of SendGrid in a $3 billion all-stock deal.

The combined company will power more than 600 billion annual interactions every year for more than 140,000 customers, Twilio said.

“Our goal is to provide a complete platform for every form of customer engagement,” said Jeff Lawson, Twilio co-founder and CEO.

Denver-headquartered SendGrid will operate as a wholly owned subsidiary of Twilio and will continue to be led by SendGrid CEO Sameer Dholakia, reporting to Lawson.

Twilio allows software developers to embed phones, VoIP, and messaging into web, desktop, and mobile software using a set of APIs.

SendGrid is a cloud-native email delivery platform that delivers 30 billion emails each month for Internet and mobile-based customers like Airbnb, Spotify and Uber.

The acquisition was first announced in October last year. It has closed for $1 billion more than anticipated as both company’s shares have been soaring.

“At Twilio, we’ve been investing for 11 years to build the customer engagement platform that developers and companies can use to build world class experiences. We started by building the industry leading APIs for voice and SMS, and have since added video, Facebook Messenger, and WhatsApp as means for companies to communicate with their customers,” Lawson added in a blog.

“SendGrid has been doing the same thing, but they started by building the industry’s leading developer platform for email. If you’ve been at a hackathon, conference or meetup in the past 10 years you may have seen someone in a red Twilio track jacket and someone in a blue SendGrid hoodie serving developers side-by-side. We’re excited about the opportunity to continue that journey of serving the developers in our community, as one unified platform.”