🔗 CORS in Phoenix

Single page applications (SPAs) are on the rise, but they can't function without a solid API backend. Phoenix, built with Elixir, shines as a powerful JSON API option, especially for those using modern JavaScript frameworks. However, when it comes to connecting SPAs to an API, understanding Cross-Origin Resource Sharing (CORS) is crucial. CORS is a security feature that requires careful management of request headers to ensure that browsers can access resources from different origins.

This article delves into how to handle CORS in a Phoenix application. It introduces useful tools like CORSPlug and Corsica to manage CORS headers effectively. The author also highlights a common pitfall related to pre-flight requests that could lead to 404 errors and offers solutions to define the necessary OPTIONS routes for your API endpoints. By clarifying these aspects, the piece provides actionable insights for developers working with Phoenix and SPAs.