API authentication is a way of protecting API access from unidentified or anonymous access. It ensures that the API is secured and accessible only by the consumers who prove an identity and whose identities are found within the API Management Platform.

WSO2 API offers following authentication mechanisms to secure your API from unauthenticated access.

Securing APIs using OAuth2 Access Tokens

Secure APIs Using API Keys

Secure APIs Using Mutual SSL

Secure APIs Using Basic Authentication