# AuthenticationAPIs.com

> Discover APIs for user sign-in, sessions, tokens, MFA, SSO, passkeys, enterprise identity and machine-to-machine authentication.

## Machine-readable resources
- ARD manifest: https://authenticationapis.com/.well-known/ard.json
- Structured catalog: https://authenticationapis.com/api/catalog.json

## Representative tasks
- Find authentication APIs for user sign-in and session management
- Find API-first authentication providers with OAuth, OIDC, MFA or passkeys
- Find authentication APIs for B2B SSO and enterprise user management
- Find authentication APIs for machine-to-machine services or AI agents

## Curated API index
- Amazon Cognito User Pools API — AWS: API for configuring user pools and authenticating users, with support for server-side and client-side authentication and federated identity flows.
- Auth0 Authentication APIs — Auth0: Authentication and authorization APIs for login flows, token issuance, API access and identity workflows.
- Clerk Backend API — Clerk: REST backend API for users, organizations, sessions, invitations, API keys, M2M tokens and authentication-related resources.
- Descope REST API — Descope: REST API covering authentication methods, sessions and identity management including OTP, magic links, OAuth, SAML, WebAuthn and TOTP.
- Firebase Auth REST API — Google Firebase: REST API for creating users, signing users in, exchanging custom tokens and managing Firebase Authentication identities.
- FusionAuth APIs — FusionAuth: REST APIs for login, registration, users and authentication workflows with API key, JWT, client-credentials and other supported authentication modes.
- Okta Authentication API — Okta: API for primary authentication, multifactor enrollment and verification, password recovery and account unlock flows.
- Stytch Authentication APIs — Stytch: Developer authentication platform with APIs for consumer and B2B auth, SSO, MFA, sessions and machine-to-machine authentication.
- Supabase Auth — Supabase: Authentication service with APIs and SDKs for password, magic-link, OTP, social login, SSO and JWT-based sessions.
- WorkOS AuthKit API — WorkOS: Authentication and user-management APIs supporting passwords, SSO, social login, MFA, Magic Auth and organization-aware flows.

Source: Official provider documentation; curated 2026-09-17.
Semantic domain: authenticationapis.com