API authentication is a crucial aspect of securing your application and ensuring that only authorized users can access specific resources. There are several common authentication schemes used in APIs, each with its own strengths and weaknesses.

One popular method is Token-Based Authentication, where a user provides their credentials, and upon successful authentication, the server generates a token. This token is then used for subsequent requests, allowing the user to access resources without needing to re-enter their credentials each time. This method is particularly effective for stateless APIs, as it does not require the server to maintain session information ¹⁵.

Another common scheme is Basic Authentication, which involves sending a username and password with each request. While simple, this method can be vulnerable to interception if not used over secure channels like HTTPS ².

Other methods include API Keys, which are unique identifiers for applications, and OAuth, which allows third-party applications to access user data without sharing passwords ²³. Each method has its use cases, and the choice depends on the specific requirements of your application.