Tesseral – Open-Source Auth
Hi folks! I'm Ulysse, and Tesseral (https://github.com/tesseral-labs/tesseral) is open-source auth for B2B SaaS. Early in my career, I worked on enterprise auth and security features at Segment. I've been obsessed with the subtle details of enterprise software ever since. For example, I wrote an implementation of SAML in the early days of the COVID pandemic because I thought it was fun. Over the years, I've felt frustrated that too few people have seemed interested in making auth obvious for developers of business software. Auth really doesn't need to be so confusing. We…
In plain words
Tesseral is an open-source authentication system designed for B2B SaaS applications. It allows developers to implement user login, authentication, and access management without the complexity typically associated with enterprise auth. Built by someone with experience in enterprise security at Segment, Tesseral provides an alternative to commercial services like Auth0 or Clerk, letting software engineers handle authentication details efficiently so they can focus on building product features.
written from the facts on this page · September 2026
From the sources
In the maker’s words, at launch
Hi folks! I'm Ulysse, and Tesseral (https://github.com/tesseral-labs/tesseral) is open-source auth for B2B SaaS. Early in my career, I worked on enterprise auth and security features at Segment. I've been obsessed with the subtle details of enterprise software ever since. For example, I wrote an implementation of SAML in the early days of the COVID pandemic because I thought it was fun. Over the years, I've felt frustrated that too few people have seemed interested in making auth obvious for developers of business software. Auth really doesn't need to be so confusing. We made Tesseral to help software engineers get B2B auth exactly right – and focus their energy on building the features that users want. You can use Tesseral to stand up a login page, authenticate your users, and manage their access to resources. Think of it like Auth0 or Clerk, but open source and built specifically for B2B apps. Among other things, that means that it’s designed for B2B multi-tenancy and includes enterprise-ready features like single sign-on (SAML SSO), multi-factor authentication (MFA), SCIM provisioning, and role-based access control (RBAC). For those who expose public APIs, you can use Tesseral to manage API keys for your customers. You can even limit the scope of API keys to specific actions by using our RBAC feature. We've taken care to make Tesseral powerful and secure enough to power real enterprise software but still leave it simple enough for any software developer to use. You don't have to be a security expert to implement Tesseral. (By default, therefore, Tesseral imposes a few opinions. Let us know if you have a good reason to do something unusual, and we'll work something out.) If you want to experiment with Tesseral, you can host it yourself or use our hosted service. The hosted service lives at https://console.tesseral.com. You can find documentation here: https://tesseral.com/docs. Here are a few simple demos: https://www.youtube.com/watch?v=IhYPzz3vB54 https://www.youtube.com/watch?v=t-JJ8TNjqNU https://www.youtube.com/watch?v=mwthBIRZO8k We're in the early stages of the project, so we still have some gaps. We have more features, bug fixes, SDKs, and documentation on the way. What have we missed? What can we do better? We're eager to hear from the community!
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