CORS in Ruby on Rails API: Practical Setup and Pitfalls
If you build a Rails API and your frontend runs on a different origin, CORS stops being theory pretty fast. You ship an endpoint, the browser blocks it, and suddenly everyone is staring at a console error that says “No ‘Access-Control-Allow-Origin’ header.” Rails itself does not magically solve CORS. You need to configure it intentionally, and if you get lazy with wildcards or credentials, you can open up more access than you meant to. ...