Sierra acquires Anon to push customer AI agents into browser workflows

Sierra, the San Francisco company founded by Bret Taylor and Clay Bavor that sells customer-facing AI agents to enterprises, acquired Anon on Nov. 5, DevCuration reported. Anon builds infrastructure that lets agents sign in to websites and operate through interfaces that lack APIs. Financial terms were not disclosed. Daniel Mason, Anon's former co-founder and CEO, joins Sierra as an Agent Strategist focused on financial services.

Anon had raised more than $13 million and served hundreds of customers, Mason said in the acquisition announcement cited by DevCuration. Union Square Ventures backed the company in 2024 around permissioned access to services without open APIs. Sierra introduced Horizon in July 2026 for multi-day goals such as originating a loan or obtaining prior authorization, and reported more than $400 million in annual recurring revenue in a late-October founder update. Browser execution is meant to extend those workflows into portals Sierra does not control.