Tesseral, a San Francisco, CA-based open-source authentication infrastructure for B2B software companies, has emerged from stealth with $3.3 million in seed funding.
Investors
The round was led by Y Combinator, with participation from prominent angel investors such as YC co-founders Jessica Livingston and Paul Graham, Calvin French-Owen (Segment), Steve Bartel and Nick Bushak (Gem), and Mike Wiacek (Stairwell).
Y Combinator (YC) is a startup accelerator that provides early-stage startups with funding, mentorship, and resources to help them grow. It invests in early-stage startups, typically at the seed stage, in technology, healthcare, fintech, biotech, and consumer products.
Tesseral Use of Funds
The company will use the funding to accelerate the development of its open-source authentication platform.
About Tesseral
Founded by Ned O’Leary and Ulysse Carion, Tesseral provides open-source authentication infrastructure for business-to-business (B2B) software companies to simplify identity and access management. It enables developers to embed secure, scalable authentication into B2B software with minimal code. By eliminating the complexities of authentication, Tesseral empowers developers to focus on building core product features while ensuring a world-class security posture. Tesseral already serves customers such as Gumloop, GovAI, and RunReveal.
Funding Details
Company: Codomain Data Corporation (Tesseral)
Raised: $3.3M
Round: Seed
Funding Date: May 2025
Lead Investor: Y Combinator
Additional Investors: Jessica Livingston, Paul Graham, Calvin French-Owen, Steve Bartel, Nick Bushak, Mike Wiacek
Company Website: https://tesseral.com/
Software Category: Open Source B2B Authentication / DevTools
Source: Phttps://www.businesswire.com/news/home/20250506853608/en/