Replit
api
CORS Credentials and Cookies Not Sent
Authenticated API requests fail because cookies aren't sent. CORS blocks credentials even after preflight succeeds.
Credentials mode and CORS headers must align for cookies to transmit.
Error Messages You Might See
Credentials mode is 'include' but Access-Control-Allow-Credentials header is missing
Access-Control-Allow-Origin cannot use wildcard
Common Causes
- Client not sending credentials: 'include' in fetch
- Server not sending Access-Control-Allow-Credentials: true
- Access-Control-Allow-Origin set to * (incompatible with credentials)
- Cookie SameSite=Strict blocking cross-site cookies
How to Fix It
Client: fetch(url, { credentials: 'include' }). Server: response header Access-Control-Allow-Credentials: true. Set Access-Control-Allow-Origin to specific domain, NOT *. Ensure cookies have SameSite=None; Secure for cross-site. Configure Spring CORS with allowedOriginPatterns and allowCredentials=true.
Real developers can help you.
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SWE with 15+ years of experience building and maintaining web apps and extensive BE infrastructure
Caio Rodrigues
I'm a full-stack developer focused on building practical and scalable web applications. My main experience is with **React, TypeScript, and modern frontend architectures**, where I prioritize clean code, component reusability, and maintainable project structures.
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Software Engineer @ AWS
Jared Hasson
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SW engineer with 6+ years of experience,
I worked with React/Node/Python
did projects with React+Capacitor.js for ios
Supabase expert
PawelPloszaj
I'm fronted developer with 10+ years of experience with big projects. I have small backend background too
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Software Engineer with over 10 years of experience on Startups, Government, big tech industry & consulting.
Mehdi Ben Haddou
- Founder of Chessigma (1M+ users) & many small projects
- ex Founding Engineer @Uplane (YC F25)
- ex Software Engineer @Amazon and @Booking.com
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
How do I send cookies with fetch?
fetch(url, { credentials: 'include' }) - must also set server headers correctly
Can I use Access-Control-Allow-Origin: *?
Not with credentials. Use specific domain or null for local testing