cors-configuration-validator

CORS validation for Cloudflare Workers checks that your API endpoints correctly implement Access-Control headers, handle OPTIONS preflight requests, validate origins safely, and restrict methods and headers appropriately. This Skill automates that validation across development, staging, and production environments to catch misconfigurations before deployment.

The validator confirms presence and correctness of Access-Control-Allow-Origin, Access-Control-Allow-Methods, Access-Control-Allow-Headers, and related CORS headers. It verifies these headers are set properly on responses to cross-origin requests and that preflight OPTIONS responses include the required headers.

Preflight handling validates that your Worker correctly responds to OPTIONS requests with appropriate CORS headers before the browser sends the actual request. The validator confirms this flow works properly so cross-origin requests from browsers succeed without being blocked.

Yes. The validator checks for overly permissive configurations like wildcard origins or unrestricted method/header allowance. It ensures your origin allowlist is secure and your allowed methods and headers are appropriately scoped to prevent unintended cross-origin access.

Origin validation in the validator checks that your Worker only allows requests from trusted origins rather than accepting all origins. This prevents malicious cross-origin requests and ensures only intended applications can access your API endpoints.