Designing PHP REST APIs for Shared Hosting Constraints

Most REST API guides assume a server environment you fully control. Namecheap Stellar Plus shared hosting is not that environment, and a chunk of our early debugging on the Radixivity Admin backend was tracing failures back to that gap.

The clearest example: getallheaders() is a common way to read custom auth headers in PHP, but it's not reliably available across shared-hosting PHP configurations. We replaced it with a fallback that reads from $_SERVER['HTTP_X_ADMIN_KEY'] directly, which works consistently regardless of how the host has PHP configured.

The second constraint was HTTP method support. Some shared-hosting setups don't route DELETE requests through to PHP cleanly. Rather than fight the hosting layer, the Admin Panel's delete operations go through POST with an explicit action field — less "RESTful" by the textbook definition, but it's an API that actually works in production instead of one that's correct in theory and broken on the host we're paying for.

The broader lesson: REST conventions are guidelines for organizing an API, not a contract with your hosting provider. Know your deployment environment before you commit to a method or header pattern the docs assume you can rely on.