Build an authenticated API with Next.js API Routes and Upstash Redis

The article describes how to build a minimal authenticated REST API service using Next.js API Routes and Upstash Redis, focusing on user authentication and JWT handling without a front-end component. Upstash Redis, a serverless in-memory cloud database based on Redis, is used for storing user data, tokens, and a list of movies available through the API. The API endpoints allow client applications to request movie data, with security enforced via JWTs and a refresh token workflow. Detailed instructions are provided for setting up the Redis database, creating necessary API routes, handling user authentication, and managing JWTs and refresh tokens. The article emphasizes the importance of client-side responsibility for storing and using tokens, while also suggesting potential improvements such as optimizing data storage, enhancing security, and expanding API functionalities.