CORS Patterns
Configure Cross-Origin Resource Sharing correctly for secure API access.
- Difficulty
- intermediate
- Read time
- 1 min read
- Version
- v1.0.0
- Confidence
- established
- Last updated
Quick Reference
CORS: Never use Access-Control-Allow-Origin: * with credentials. Whitelist specific origins. Handle preflight (OPTIONS) requests. Set appropriate Access-Control-Max-Age. Include only needed headers in Access-Control-Expose-Headers. Validate Origin header server-side.
Use When
- Cross-origin API requests
- Frontend on different domain
- Third-party integrations
- Microservices
Skip When
- Same-origin requests
- Server-to-server calls
- Mobile native apps
CORS Patterns
Configure Cross-Origin Resource Sharing correctly for secure API access.