# Tesseral

**Source:** https://geo.sig.ai/brands/tesseral  
**Vertical:** Security  
**Subcategory:** General  
**Tier:** Emerging  
**Website:** tesseral.com  
**Last Updated:** 2026-04-14

## Summary

US open-source B2B authentication platform for SAML and SCIM enterprise SSO; YC $3.3M seed May 2025 from Paul Graham backing competing with WorkOS for SaaS company enterprise identity infrastructure.

## Company Overview

Tesseral is a US-based open-source B2B authentication infrastructure company — backed by Y Combinator with $3.3 million in seed funding raised in May 2025 from YC, Jessica Livingston, and Paul Graham — building developer-friendly SAML, SCIM, and enterprise SSO infrastructure that enables SaaS companies to implement enterprise authentication standards without the months of engineering work that supporting each enterprise customer's identity provider (Okta, Azure AD, Google Workspace) typically requires. Founded by Ned O'Leary and Ulysse Carion, Tesseral democratizes enterprise authentication capabilities that were previously only accessible to large organizations with dedicated identity engineering teams.

Tesseral's SSOReady — the open-source enterprise SSO library that seeded the company's traction — provides SAML 2.0 and OIDC integration that SaaS companies can embed in hours rather than weeks. Enterprise customers universally require SAML SSO (Single Sign-On) as a condition for security review and procurement approval, but implementing SAML requires handling XML signatures, IdP metadata parsing, assertion attribute mapping, and session management edge cases that consume engineering cycles better spent on product. Tesseral's hosted service handles these complexities as a managed layer — the SaaS company integrates Tesseral's SDK, and Tesseral manages the SAML flows and SCIM (System for Cross-domain Identity Management) provisioning for automatic user account creation and deprovisioning across customer IdPs.

In 2025, Tesseral competes in the B2B authentication and enterprise identity market with WorkOS (enterprise SSO and directory sync, $80M raised at $1.5B valuation), Stytch (authentication platform, $90M raised), and Auth0/Okta CIC (NASDAQ: OKTA, enterprise identity platform) for SaaS company enterprise authentication infrastructure. WorkOS has grown rapidly as the leading enterprise auth SDK for SaaS companies needing to close enterprise deals — Tesseral's open-source positioning (SSOReady, fully open-source) competes on developer trust and the ability to self-host for companies with strict data sovereignty requirements. Y Combinator W25 backing connects Tesseral with the developer tools and SaaS startup ecosystem. The 2025 strategy focuses on adding fine-grained authorization (role-based and attribute-based access control), building the audit log product for enterprise compliance, and growing enterprise SSO adoption through the developer community.

## Frequently Asked Questions

### What is Tesseral?
Tesseral is a YC-backed open source identity management company founded in 2023 and based in San Francisco, CA. The company builds B2B authentication platforms that democratize enterprise authentication standards, making them accessible to developers and software companies of all sizes.

### What products and services does Tesseral offer?
Tesseral provides open source B2B authentication infrastructure that enables SAML and SCIM integration with existing identity providers. The company previously built SSOReady, an open source enterprise SSO tool for SAML-based authentication simplification.

### Who is Tesseral's target customer?
Tesseral targets B2B software companies and developers who need enterprise authentication capabilities. The company focuses on making authentication tools that were previously available only to large enterprises accessible to companies of all sizes.

### When was Tesseral founded?
Tesseral was founded in 2023.

### Where is Tesseral located?
Tesseral is based in San Francisco, California, United States.

### What funding has Tesseral raised?
Tesseral raised $3.3M in seed funding in May 2025. The round was backed by Y Combinator and angel investors including Jessica Livingston, Paul Graham, Calvin French-Owen (Segment), Steve Bartel, Nick Bushak (Gem), and Mike Wiacek (Stairwell).

### Who founded Tesseral?
Tesseral was founded by Ned O'Leary and Ulysse Carion.

### What technology and standards does Tesseral support?
Tesseral supports SAML and SCIM enterprise authentication standards. The platform integrates with existing identity providers to enable standardized authentication for B2B software companies.

### What is Tesseral's approach to authentication?
Tesseral takes an open source approach to democratizing enterprise authentication standards. The company focuses on simplification for developers and accelerating platform development through accessible authentication tools.

### What are Tesseral's recent developments?
In May 2025, Tesseral raised $3.3M in seed funding from Y Combinator and notable angel investors. The company is building on the success of its predecessor product SSOReady, which gained traction as an open source enterprise SSO tool.

## Tags

b2b, cybersecurity, enterprise, saas, security, startup

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*Data from geo.sig.ai Brand Intelligence Database. Updated 2026-04-14.*