Sierra, the AI customer-service agent company co-founded by Bret Taylor and Clay Bavor, has acquired Anon, a San Francisco startup whose software lets AI agents sign in to websites and work through them the way a person would. The deal was announced on November 5, 2026, in a post on Sierra's blog written by Anon's chief executive, Daniel Mason.
Neither company disclosed the price or other terms. Anon's technology and team are joining Sierra, where they will handle the browser steps in Sierra's agents: signing in to a website, moving through a portal or entering information into a form, so that more tasks can be finished without a person stepping in.
What Anon built
Anon started out with an AI personal assistant. Early use of that product pushed the company toward a broader problem: much of the software that agents need to use has no API, only a website meant for humans. Anon set out to build the infrastructure that lets enterprise agents use those sites securely, and Mason wrote that the team thought of it as "Plaid for AI agents."
Its stack covered authentication and credential handling, browser infrastructure, an agent harness and an SDK that developers could embed in their own products. According to Unite.AI, Anon also offered a visual builder that records a workflow so an agent can replay it, a hosted-browser playground and sandbox tests before deployment, and audit logs, telemetry and a live dashboard once a workflow was running. Results could be exported as CSV, PDF, screenshots or page content, with REST APIs returning structured JSON.
Security was a large part of the pitch. Unite.AI reported that Anon does not store user credentials but streams them through isolated environments, separates customer tenants, uses role-based access controls and completed a SOC 2 Type II audit in July 2025.
Mason wrote that reliability became the company's central focus, because it is the hardest problem in browser use. Anon's agents were built to handle sensitive data and multi-factor authentication, run a single task for hours and recover when something failed.
“We built Anon to help enterprise AI agents securely use websites the way people do.”
Customers and track record
According to Mason, Anon's product was used by hundreds of customers, from AI startups to publicly traded companies, and completed hundreds of thousands of complex tasks in production. The company also built and deployed agents for large enterprises in banking, healthcare and enterprise software, some of which are also Sierra customers.
When Anon launched publicly in April 2024, it described itself as an integration platform for the internet and named MultiOn, Delphi and Personal.ai among its early clients, VC Access Online reported at the time.
Why Sierra is buying
Sierra builds AI agents that companies use for customer service, and says those agents handle billions of customer interactions each year. In July 2026 it introduced Horizon, a product for longer-running goals such as loan origination or prior authorization, which can involve coordinating interactions over days or months. Unite.AI reported that Horizon customers pay for outcomes delivered rather than for the AI tokens used.
Those goals often require working across several systems, including services that have no APIs. Mason wrote that an agent that stops at a login screen or a manual portal step has not completed the job, and that Anon will help Sierra's agents close that gap. Unite.AI noted that such gaps matter more under Sierra's outcome-based pricing.
Mason said the two companies were solving related problems for many of the same customers, with similar demands on security and reliability. He also argued that better models and agent harnesses have made browser agents far more reliable, which made this the right moment to join a larger company.
The founders and the funding
Anon said it raised more than $13 million in total. It debuted in April 2024 with $6.5 million, combining a seed round co-led by Union Square Ventures and Abstract Ventures with a pre-seed round led by Impatient Ventures and ex/ante, according to VC Access Online. Blocktower Ventures was also an investor, and angel backers included Product Hunt founder Ryan Hoover, Gokul Rajaram, Behance founder Scott Belsky and Replit chief executive Amjad Masad. Investors in any later funding were not disclosed.
Anon was co-founded by Mason and Kai Aichholz. Mason previously co-founded Spring Labs, a data security and identity company for financial services, and was a partner at Framework Ventures. Aichholz, an MIT graduate, was chief technology officer at Alaffia Health and earlier worked at Amazon and Goldman Sachs. Sierra's announcement also pictured Anon team members Richárd Hruby and Hardik Patil with Taylor and Bavor. The companies did not say how many people are joining Sierra or what will happen to Anon's existing product and customers.
