I’m having trouble with my Delphi application when trying to make API calls to RapidAPI endpoints. I’m using the REST client component that comes with RAD Studio but keep getting a 401 unauthorized error message.
I’ve made sure to include both the x-rapidapi-key and x-rapidapi-host headers in my REST component configuration, but the authentication still fails. The API key should be valid since I just generated it from my RapidAPI dashboard.
Has anyone else run into this issue when working with RapidAPI and Delphi? I’m wondering if there’s something specific about how the REST component handles these headers that might be causing the problem. Any suggestions on what I might be missing or doing wrong would be really helpful.
I’ve hit this same issue with RapidAPI. Usually it’s header encoding or timing problems. First, check if your REST component URL-encodes the headers properly - especially the API key. Special characters get mangled during transmission more often than you’d think. Also verify you’re hitting the right endpoint URL. RapidAPI uses different base URLs for different subscription tiers, so the wrong one throws a 401 even with valid credentials. I’d test those same headers in Postman first to confirm they work outside Delphi, then compare the raw HTTP requests to spot what’s different in your implementation.
Header order bit me hard with Delphi’s REST components and RapidAPI. Setting headers after configuring the request URL messed up my auth flow. Now I always set x-rapidapi-key and x-rapidapi-host right after initializing the REST request, before anything else. Also check if your Delphi version has SSL/TLS issues with RapidAPI’s servers - I’ve had to manually set the TLS version to get the auth handshake working. And don’t forget Content-Type needs to match exactly what the endpoint wants, even on GET requests where you’d think it wouldn’t matter.
hey, double check that you’re not using params instead of actual headers, i had that issue too. also, make sure your host header exactly matches the docs. rapidapi can be super picky about formatting - no extra slashes or spaces.