Tesseral: Open-Source Auth Infrastructure for B2B SaaS

Tesseral is an open-source authentication infrastructure for business software (B2B SaaS). It's a multi-tenant, API-first cloud service compatible with any tech stack. Developers can use the managed service at console.tesseral.com or self-host. It bundles everything needed for user management: customizable login pages, B2B multitenancy, user impersonation, self-service configuration, various login methods (magic links, social login, SAML, SCIM), role-based access control (RBAC), multi-factor authentication (MFA), passkeys/WebAuthn, authenticator apps (TOTPs), API key management, user invitations, and webhooks. SDKs are available for React, Flask, and more, simplifying frontend and backend integration.