HubSpot has agreed to acquire Warmly, a San Francisco startup that identifies the people visiting a company's website and uses AI agents to turn them into sales meetings. Warmly chief executive Max Greenwald announced the agreement on June 30, 2026.
Financial terms were not disclosed, and neither company gave a date for closing the deal.
Warmly told customers that, for now, nothing changes: contracts, pricing, account teams, the product and its integrations stay as they are, and its agents keep running. Over time it plans to connect its data and agents across HubSpot's customer platform.
What Warmly built
Warmly made its name with person-level website intent: working out who is behind anonymous website visits, including people who never fill in a form. Greenwald said the company could identify more than half of those visitors.
It then added two AI agents. The Inbound Agent tries to convert visitors while they are on the site, through chat, personalised pages, pop-ups and meeting booking. The TAM Agent works outside the website, building target audiences, scoring intent and running outbound campaigns before buyers arrive. Both draw on a shared data layer the company calls Context Graph, and Warmly says it connects to more than 40 other tools.
“The gap between building demand and winning deals is one of the hardest problems in GTM, and Warmly has cracked it in a way that directly benefits HubSpot customers. We’re excited to welcome the team to HubSpot.”
Why HubSpot is buying
HubSpot, founded in 2006 in Cambridge, Massachusetts, has more than 248,000 customers in over 135 countries, according to CMSWire. Greenwald noted that HubSpot has spent more than 20 years building connected products for the whole customer journey, so that customers do not have to stitch together many separate systems. Warmly's tools sit between a buyer showing interest and a sales team engaging them, and CX Today reported that the deal gives Warmly access to HubSpot's global customer base, engineering resources and wider product ecosystem.
Angela DeFranco, general manager and vice president of product at HubSpot, said Warmly had solved one of the hardest problems in go-to-market in a way that directly benefits HubSpot customers.
The two companies already knew each other well. HubSpot was Warmly's first integration in 2023, and Greenwald said the number of Warmly customers connected to HubSpot grew from 20 that year to 223 paying customers in 2026, CMSWire reported. In his post, Greenwald said both companies believe the next generation of sales and marketing will be run by people and AI agents working as one system.
The founders and the funding
Greenwald started Warmly six years ago with co-founders Carina Boo and Alan Zhao. Its 2023 funding announcement gave its founding year as 2020 and listed Y Combinator and Soma Capital among its backers.
In October 2023 Warmly raised an $11 million Series A from investors including Felicis, NFX, Zoom, F-Prime Capital and Maven Ventures. In February 2025 it added a $6 million Series A+ led by RTP Global, with Felicis and NFX taking part, bringing its Series A funding to $17 million.
At the time of that second round, Warmly said it had reached $3 million in annual recurring revenue and passed 300 customers in 2024, among them New Relic, Cyberhaven and CircleCI. It planned to double its sales and marketing team and grow to about 50 staff worldwide, including 20 in Europe. It did not report a headcount at the time of the sale.
What happens to customers
Existing Warmly customers keep their current contracts and pricing. Greenwald said the company would keep its commitments to them and that the longer-term goal is to make Warmly more capable by linking it to HubSpot's data and agents.
He also thanked the company's investors and staff, and wrote that AI agents will shape how millions of people deal with businesses, making those experiences either much more useful or much more intrusive. He said Warmly would continue that work as part of HubSpot.
