Amazon’s Ring division evaluated more than 40 AI voice vendors before picking its winner. Vapi, a startup most people outside the enterprise AI world have never heard of, walked away with the contract, and Ring proceeded to migrate 100% of its inbound customer support calls onto the platform.

That kind of endorsement tends to open wallets. Vapi just closed a $50M Series B led by Peak XV Partners, pushing its valuation to $500M. Microsoft’s M12, Kleiner Perkins, and Bessemer Venture Partners also participated, bringing the company’s total funding to $72M.

The numbers behind the noise

Vapi currently processes between 1 million and 5 million calls per day. It has surpassed 1 billion total calls handled to date, a milestone driven almost entirely by enterprise customers rather than hobbyist developers tinkering with voice bots on weekends.

The company’s enterprise business has grown roughly 10 times since early 2025. Vapi employs around 100 people and plans to use the fresh capital to expand its engineering and go-to-market teams.

Why Ring’s bet matters more than the valuation

Ring didn’t just trial a few vendors and pick the cheapest. The unit tested north of 40 voice AI platforms before committing. The real stress test came during the 2024 holiday season, when inbound call volumes spike dramatically as millions of people set up new Ring doorbells and cameras they got as gifts. Vapi’s platform held up under that surge, which apparently sealed the deal.

The AI agent economy and what investors should watch

Vapi sits at the infrastructure layer of what’s becoming a massive shift in how businesses handle customer interactions. The company isn’t building the AI agents themselves. It provides the plumbing: the voice processing, telephony integration, and real-time inference pipeline that makes AI phone calls actually work.

The competitive landscape is also heating up. Bland AI, Retell AI, and a growing roster of voice AI startups are chasing the same enterprise contracts. But the Ring deployment gives Vapi something its competitors lack: a proof point at genuine scale with one of the most recognizable consumer hardware brands on the planet.

Investors should watch two things closely. First, whether Vapi’s 10x enterprise growth rate sustains through the back half of 2025 or starts to plateau as early adopters finish their migrations. Second, whether Amazon deepens the relationship beyond Ring into other business units.