Authentication APIs

Authentication and authorization services

7 APIs in this category
Showing 7 of 7 APIs

Auth0

Flexible authentication and authorization platform for applications

Auth: apiKey HTTPS CORS: Yes

GetOTP

API to quickly implement one-time password (OTP) verification flow

Auth: apiKey HTTPS CORS: No

Micro User Service

User management and authentication microservice API

Auth: apiKey HTTPS CORS: No

MojoAuth

Passwordless authentication platform for secure and seamless login

Auth: apiKey HTTPS CORS: Yes

SAWO Labs

Passwordless authentication service for fast and secure user login

Auth: apiKey HTTPS CORS: Yes

Stytch

Modern authentication infrastructure for developers and apps

Auth: apiKey HTTPS CORS: No

Warrant

Authorization and access control APIs for your apps

Auth: apiKey HTTPS CORS: Yes

Best Authentication APIs for Developers

An authentication API allows developers to implement secure user login, OAuth social sign-in, multi-factor authentication, and identity management without building these complex systems from scratch. These APIs handle token issuance, session management, and user verification.

CodeHelper's curated authentication API collection includes APIs covering OAuth providers, SSO services, JWT utilities, and identity management platforms.

What to look for in an authentication API

  • Standards compliance: Look for APIs that support OAuth 2.0 and OpenID Connect for maximum interoperability.
  • MFA support: Multi-factor authentication options (TOTP, SMS, email) add critical security layers for sensitive apps.
  • SDK availability: Official SDKs for your language or framework significantly reduce integration time.

How to use this API directory

  1. Browse the curated list of APIs below.
  2. Click any API to visit its documentation.
  3. Check the Auth column to understand what credentials you need.

Whether you are building a SaaS login system or a social sign-in feature, this free curated API directory saves you hours of research.

Related

toolBase64 Encoder/DecoderEncode and decode Base64 strings, files, images with data URL support. Upload files or paste text for instant conversion.toolJWT Decoder & ValidatorDecode, validate, and inspect JSON Web Tokens (JWT). Parse header, payload, verify signatures with HMAC algorithms, and check token expiration: all client-side.toolJWT GeneratorCreate and sign JSON Web Tokens with HMAC algorithms, standard claims, custom payloads, and client-side signing.