Stack Auth
Stack Auth is an open-source authentication and user management platform positioned as a self-hostable alternative to closed-source providers like Clerk and Auth0. It bundles password, OAuth / SSO, and two-factor sign-in flows with organizations, teams, role-based access control, impersonation, webhooks, and pre-built UI components built on shadcn/ui (or a headless SDK). Stack Auth is available as a hosted SaaS at app.stack-auth.com and as a self-hosted deployment from the stack-auth/stack monorepo on GitHub. Authentication is JWT-based. Y Combinator-backed.
Stack Auth publishes 5 APIs on the APIs.io network. Tagged areas include Authentication, User Management, Open Source, Self-Hosted, and Identity.
Stack Auth’s developer surface includes documentation, GitHub presence, pricing, engineering blog, and 2 more developer resources.
APIs
Stack Auth REST API
REST API for managing users, sessions, OAuth providers, teams, organizations, permissions, and webhooks. Used by Stack Auth's own SDKs and available for custom backend integrati...
Stack Auth Webhooks
Outbound webhook events for user lifecycle, team / organization membership, and permission changes. Customers register endpoint URLs and verify delivery via signed payloads.
Stack Auth React / Next.js SDK
Frontend SDK distributed as @stackframe/stack on npm. Provides React components, hooks, and Next.js App Router middleware for sign-in, sign-up, account settings, and team / orga...
Stack Auth CLI
Project bootstrap CLI distributed as @stackframe/init-stack on npm, invoked with `npx @stackframe/init-stack@latest` to wire Stack Auth into a new or existing project.
Stack Auth Self-Hosted (stack-auth/stack)
Open-source monorepo containing the Stack Auth backend (Next.js + Postgres) and dashboard. Deployable on customer infrastructure as an alternative to the hosted SaaS at app.stac...