Stack Auth

Stack Auth is an open-source authentication and user infrastructure engine built for TypeScript and React stacks. It provides drop-in authentication components, organization switching, and permission checks while executing entirely on your own infrastructure. A single container deployment writes directly to your PostgreSQL database, preventing customer identities and session state from leaking to third-party identity clouds.

Why Stack Auth instead of Clerk

Clerk delivers a polished developer experience for React and Next.js applications, but it operates as a multi-tenant cloud service. Every authentication attempt, session token verification, and user profile query crosses Clerk's servers. For DevOps engineers, this creates external dependencies on third-party availability, limits compliance options under strict data sovereignty mandates, and introduces variable monthly active user charges that spike as an application scales. Stack Auth mirrors Clerk's component-driven ergonomics while shifting the deployment model to an operator-controlled container. Teams run the stackauth/server image inside their own virtual private cloud, connecting it directly to an isolated PostgreSQL instance.

The operational trade-off is infrastructure responsibility. Clerk handles zero-downtime upgrades, database backups, key rotation, and edge session caching without engineering intervention. Choosing Stack Auth means taking ownership of database maintenance, monitoring background synchronization tasks, and configuring network ingress with a reverse proxy for TLS termination. In exchange, infrastructure engineers retain total control over database schemas, audit logs, network routing, and user data residency, eliminating external service lock-in and unexpected billing changes.

What it does well

• Pre-built UI components: Ships drop-in React and Next.js components for sign-in, user profiles, and organization switching that integrate directly into client codebases.
• Self-contained container: Packages the authentication API backend and administrative dashboard into a single Docker image, simplifying deployment across orchestration platforms.
• Database ownership: Stores user records, role definitions, and credentials in standard PostgreSQL tables that your team queries and backs up directly.
• Native multi-tenancy and RBAC: Supports team workspaces, nested roles, and permission checks without requiring separate authorization microservices.