TypeScript CORS Guide: What It Is and How to Enable It

Cross-Origin Resource Sharing (CORS) is a crucial aspect of web development that regulates whether a browser can access resources from a server with a different origin, often leading to errors when not properly configured. In modern web applications, which typically follow a client-server architecture, the same-origin policy imposed by browsers prevents resource sharing across different domains for security reasons. However, many applications require interaction with servers or third-party APIs of different origins, necessitating the use of CORS to lift these restrictions. The server is responsible for enabling CORS by setting appropriate headers, such as "Access-Control-Allow-Origin," to allow specific clients access. The article provides a practical guide to enabling CORS in a Node.js and TypeScript application, demonstrating the process with a sample API and a React client, and highlights the importance of server-side configuration in resolving CORS issues.