ChainGPTChainGPTHelp Center

Why am I getting a CORS error or a 403 / Cloudflare block when calling the ChainGPT API or SDK?

Updated Jun 1, 2026, 06:13 AM

A CORS error usually means you're calling the ChainGPT API/SDK directly from browser front-end code (your domain or localhost). Move the call server-side and have your backend call ChainGPT, then return the result to your front-end — that removes the browser CORS restriction.

For other cases:

  1. 403 / Cloudflare block on webapi.chaingpt.org: use the web app directly at https://app.chaingpt.org/ instead.
  2. Your server/VPS IP is blocked by Cloudflare: this is not self-serve. Send us the failing IP and the Cloudflare Ray ID so we can check it internally.
  3. It helps us if you include a screenshot of the exact error and the request you're making.

Still need help? Contact support at help.chaingpt.org with the exact error, a screenshot, your domain/IP, and the Cloudflare Ray ID if shown.