Best Practices for User Authentication in REST APIs

Other Questions API
1

I am in the process of designing a RESTful API with best practices suggested by Apigee, which includes utilizing nouns over verbs, integrating the API version into the endpoint URLs, and employing two routes per resource collection along with appropriate HTTP methods like GET, POST, PUT, and DELETE.

Currently, I am focusing on implementing a user login system, but I am uncertain about the recommended RESTful approach for user authentication. At this stage, security measures are not my priority; I am solely concentrating on the login workflow. (Future plans include integrating two-factor OAuth authentication and using HMAC, among others.)

Here are some potential approaches for handling login:

  • A POST request to an endpoint such as <code>https://api...com/v1/authenticate.json</code>
  • A PUT request to a URL like <code>https://api...com/v1/accounts.json</code>
  • Perhaps something else I haven’t considered yet…

What is the most effective RESTful method for implementing user login?

2

When implementing a user login system in a RESTful API, the recommended approach is to use a POST request. This method is typically more suitable for actions that modify the state or initiate a session.

Here’s a simple and efficient way to handle your login workflow:

  • Use a POST request to an endpoint like https://api.example.com/v1/auth/login. This is clear and conveys that the operation is not idempotent.
  • In your request body, include the user credentials, e.g., email and password, in JSON format.
  • Once validated, generate a token (JWT is a popular choice) and return it in the response. This token will be used for subsequent requests to secure endpoints.

The POST method is preferred here because authentication is an action that often results in a state change—specifically generating a token or session. This keeps your API aligned with REST principles and optimizes your user login workflow.