Clerk is a drop-in authentication and user management platform for web and mobile applications. The product spans sign-up / sign-in flows, user profiles, multi-factor authentication, passkeys, social sign-on, magic links, bot and fraud detection, organizations (B2B / multi-tenant) with custom roles and invitations, and a Billing product for subscriptions. The Backend API at api.clerk.com is authenticated with a Bearer secret key and has an OpenAPI specification. Frontend SDKs cover Next.js, React, React Router, Expo, Astro, TanStack React Start, Chrome Extension, and vanilla JavaScript. Backend SDKs cover Node, Go, Python, Ruby, Java, PHP, and C#. Webhooks are delivered via Svix.
APIs.json: https://raw.githubusercontent.com/api-evangelist/clerk/refs/heads/main/apis.yml
- Authentication
- User Management
- Identity
- Passkeys
- MFA
- B2B
- Organizations
- Billing
- Created: 2026-05-23
- Modified: 2026-05-30
Server-to-server REST API for managing users, sessions, organizations, organization memberships, organization invitations, JWT templates, sign-in tokens, OAuth applications, SAML connections, allowlist / blocklist identifiers, actor tokens, webhooks, and instance settings. Authenticated with a Bearer secret key (sk_test_... or sk_live_...). Versioned under /v1.
- Human URL: https://clerk.com/docs/reference/backend-api
- Base URL:
https://api.clerk.com
- Backend
- REST
- Users
- Sessions
- Organizations
- Documentation
- OpenAPI — OpenAPI Specification
- Postman Collection — Postman Collection 2.1
- Open Collection — Open Collection 1.0
Browser-facing API consumed by Clerk's frontend SDKs and ClerkJS for sign-up, sign-in, session refresh, and user profile mutations. Endpoint is instance-specific (subdomain on clerk.accounts.dev or a customer vanity domain). Authenticated with the publishable key and short-lived client tokens.
- Human URL: https://clerk.com/docs/reference/frontend-api
- Base URL:
https://clerk.accounts.dev
- Frontend
- REST
- Sessions
Webhook events delivered via Svix for user, session, organization, email, SMS, and role lifecycle changes. Customers configure endpoints in the dashboard and verify signatures with the Svix libraries.
- Human URL: https://clerk.com/docs/integrations/webhooks/overview
- Base URL:
customer-configured
- Webhooks
- Events
- Svix
- Documentation
- AsyncAPI — AsyncAPI Specification
- Postman Collection — Postman Collection 2.1
- Open Collection — Open Collection 1.0
Official ClerkJS browser library and monorepo of framework adapters (Next.js, React, Expo, React Router, Astro, Chrome Extension, TanStack). Powers Clerk's prebuilt UI components and headless hooks.
- Human URL: https://github.com/clerk/javascript
- Base URL:
https://github.com/clerk/javascript
- SDK
- JavaScript
- Frontend
Next.js integration covering App Router and Pages Router, middleware, route handlers, server components, and server actions. Distributed from the @clerk/nextjs package inside the JavaScript monorepo.
- Human URL: https://clerk.com/docs/quickstarts/nextjs
- Base URL:
https://github.com/clerk/javascript
- SDK
- Next.js
- Frontend
React components, hooks, and providers from the @clerk/clerk-react package for plain React SPAs.
- Human URL: https://clerk.com/docs/quickstarts/react
- Base URL:
https://github.com/clerk/javascript
- SDK
- React
- Frontend
Expo / React Native bindings for Clerk supporting OAuth via deep links, secure session storage, and biometrics.
- Human URL: https://clerk.com/docs/quickstarts/expo
- Base URL:
https://github.com/clerk/javascript
- SDK
- Expo
- React Native
- Mobile
Adapter for React Router v7 (Remix successor) covering loaders, actions, and server-rendered authentication.
- Human URL: https://clerk.com/docs/quickstarts/react-router
- Base URL:
https://github.com/clerk/javascript
- SDK
- React Router
- Frontend
Adapter for the Astro framework with components and middleware.
- Human URL: https://clerk.com/docs/quickstarts/astro
- Base URL:
https://github.com/clerk/javascript
- SDK
- Astro
- Frontend
Adapter for TanStack Start (React full-stack framework) with route-level authentication helpers.
- Human URL: https://clerk.com/docs/quickstarts/tanstack-start
- Base URL:
https://github.com/clerk/javascript
- SDK
- TanStack
- Frontend
Backend SDK for Node.js (@clerk/backend / @clerk/express / @clerk/fastify) that wraps the Backend API and verifies session JWTs.
- Human URL: https://clerk.com/docs/references/backend/overview
- Base URL:
https://github.com/clerk/javascript
- SDK
- Node.js
- Backend
Official Go SDK for the Clerk Backend API.
- Human URL: https://github.com/clerk/clerk-sdk-go
- Base URL:
https://github.com/clerk/clerk-sdk-go
- SDK
- Go
- Backend
Official Python SDK for the Clerk Backend API.
- Human URL: https://github.com/clerk/clerk-sdk-python
- Base URL:
https://github.com/clerk/clerk-sdk-python
- SDK
- Python
- Backend
Official Ruby SDK for the Clerk Backend API, with a Rails integration.
- Human URL: https://github.com/clerk/clerk-sdk-ruby
- Base URL:
https://github.com/clerk/clerk-sdk-ruby
- SDK
- Ruby
- Rails
- Backend
Official Java SDK for the Clerk Backend API.
- Human URL: https://github.com/clerk/clerk-sdk-java
- Base URL:
https://github.com/clerk/clerk-sdk-java
- SDK
- Java
- Backend
Official PHP SDK for the Clerk Backend API.
- Human URL: https://github.com/clerk/clerk-sdk-php
- Base URL:
https://github.com/clerk/clerk-sdk-php
- SDK
- PHP
- Backend
Official C# / .NET SDK for the Clerk Backend API.
- Human URL: https://github.com/clerk/clerk-sdk-csharp
- Base URL:
https://github.com/clerk/clerk-sdk-csharp
- SDK
- .NET
- C#
- Backend
Public repository of OpenAPI specifications for Clerk's APIs, used as the source for generated SDKs and documentation.
- Human URL: https://github.com/clerk/openapi-specs
- Base URL:
https://github.com/clerk/openapi-specs
- OpenAPI
- Specifications
FN: Kin Lane Email: kin@apievangelist.com