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Clerk API

Clerk API

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Clerk API is a modern user authentication service — sign up / sign in, organizations, multi-factor, SSO; optimized for React / Next.js / Remix.

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Use it when

Best React / Next.js experience (5-minute integration)

Watch for

Paid from $25/month production

First check

Create application at clerk.com/dashboard for keys. Next.js: install @clerk/nextjs, wrap layout in <ClerkProvider>.

Auth
jwt
CORS
?
HTTPS
Yes
Signup
?
Protocol
REST, Webhook
Pricing
freemium

Uptime · 30-day window

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01

About this API

Clerk is an auth-as-a-service company founded 2020, positioned as "default auth for modern SaaS". vs. Auth0 (founded 2013, veteran enterprise-grade), Clerk is younger, UX more modern, deeply optimized for React / Next.js (5-minute zero-to-complete-auth + UI components integration). Function coverage: social login (Google / GitHub / Apple / Discord), email + password, magic link, phone OTP, multi-factor (TOTP / SMS / WebAuthn), organizations (essential for B2B SaaS), SSO / SAML (enterprise tier). Killer ready-made UI components (sign-in, user button, organization switcher) let small teams achieve Stripe / Linear-level UX without designing auth UI. Free tier 10000 MAU enough for indie developer startup; production apps from $25/month. In recent years has become the de-facto first choice for new SaaS project auth.

02

What you can build

  • 1SaaS app user login / signup
  • 2Multi-tenant apps (organizations feature)
  • 3Multiple sign-in methods (social + email)
  • 4B2B SaaS SSO / SAML integration
03

Strengths & limitations

Strengths

  • Best React / Next.js experience (5-minute integration)
  • Ready-made beautiful UI components (out-of-box SaaS-quality UX)
  • Built-in organization / multi-tenant
  • Broadest ecosystem (deep Stripe / Webhook integration)

Limitations

  • Paid from $25/month production
  • Free tier 10000 MAU
  • Vendor lock-in (migrating out is complex)
04

Example request

Generic template — replace <endpoint> with the real path from the docs.
curl https://clerk.com/<endpoint> \
  -H "Authorization: Bearer $ACCESS_TOKEN"
05

Getting started

Create application at clerk.com/dashboard for keys. Next.js: install @clerk/nextjs, wrap layout in <ClerkProvider>.

06

FAQ

Clerk vs. Auth0?+

Modern React / Next.js apps: Clerk. Enterprise + complex SSO: Auth0 (broader ecosystem).

Can it be self-hosted?+

No. Clerk is pure SaaS. For self-hosting, choose Keycloak / Authentik / SuperTokens.

07

Technical details

CORS: ?HTTPS: YesSignup: ?Open source: No
Auth type
jwt
Pricing
freemium
Rate limit
默认 100 req/秒
Protocols
REST, Webhook
SDKs
javascript, typescript, react, nextjs, remix, expo
08

Tags

clerkauthenticationauthidentity