WorkOS is an API platform that adds enterprise login, identity, and security features to applications.

AuthKit - User management, authentication, and session handling with drop-in UI.
Single sign-on - Connects to SAML and OIDC identity providers through one integration.
Directory Sync - Syncs users and groups from identity providers over SCIM.
Audit Logs - Records security-relevant events for compliance and investigation.
Fine-grained authorization - Controls what each user can do inside the app.
Radar - Detects bots and fraud on authentication flows.

It is used by developers who sell to businesses and need SSO, directory sync, and audit trails without building them in-house.

Plans and usage pricing are detailed on the pricing page, with docs and an MCP server for integration help.