# Auth0 integration on an existing project on vercel **URL:** \ **Category:** Get Help\ **Tags:** other, test\ **Created:** [March 31, 2025, 9:50am UTC](https://community.auth0.com/t/auth0-integration-on-an-existing-project-on-vercel/184783 "2025-03-31T09:50:48Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![devops17](https://sea1.discourse-cdn.com/auth0/user_avatar/community.auth0.com/devops17/32/70868_2.png) [@devops17](https://community.auth0.com/u/devops17)\ **Post date:** [March 31, 2025, 9:50am UTC](https://community.auth0.com/t/auth0-integration-on-an-existing-project-on-vercel/184783/1 "2025-03-31T09:50:48Z")
I’m working on integrating Auth0 authentication into an existing Next.js project hosted on Vercel. Despite following the Auth0 Next.js SDK documentation, I’m encountering several issues during implementation. Specific Challenges: 1. Configuration Issues Getting 500 errors during authentication flow Error: Missing required configuration: baseURL 1. Redirect Problems Successful login doesn’t redirect properly to `/dashboard` Callback URLs seem mismatched despite correct settings What I’ve Tried: - Followed Auth0’s Next.js quickstart guide - Configured callback/logout URLs in Auth0 dashboard - Set up middleware and route handlers - Verified environment variables locally and in Vercel I WANT HELP IN INTEGRATING IT ---
**Author:** ![nik.baleca](https://sea1.discourse-cdn.com/auth0/user_avatar/community.auth0.com/nik.baleca/32/68749_2.png) [@nik.baleca](https://community.auth0.com/u/nik.baleca)\ **Post date:** [March 31, 2025, 5:41pm UTC](https://community.auth0.com/t/auth0-integration-on-an-existing-project-on-vercel/184783/3 "2025-03-31T17:41:32Z")
Hi @devops17 Welcome to the Auth0 Community! Regarding the first issue that you have posted, it appears that you application does not have configured the baseURL which would be either the `AUTH0_ISSUER_BASE_URL` or `AUTH0_BASE_URL`. For your second issue, you might not be redirecting the user properly inside your application. I would highly recommend to review the following posts regarding the matter: - [How to Deploy a Next.js App Secured By Auth0 to Vercel](https://developer.auth0.com/resources/guides/web-app/nextjs/vercel-deployment) - [Auth0 Examples & Templates | Vercel](https://vercel.com/templates/auth0) - [Auth0 w/ NextJS and Vercel Not Working](https://community.auth0.com/t/auth0-w-nextjs-and-vercel-not-working/111123) - [How to Deploy a Next.js App Secured By Auth0 to Vercel - #7 by byron.motoche](https://community.auth0.com/t/how-to-deploy-a-next-js-app-secured-by-auth0-to-vercel/106412/7) - [Nextjs + auth0 work at localhost, but return 404 while depoly to vercel - #6 by onlinepenguin](https://community.auth0.com/t/nextjs-auth0-work-at-localhost-but-return-404-while-depoly-to-vercel/112999/6) - [Vercel Integration with Auth0](https://auth0.com/docs/customize/integrations/integrate-with-vercel) Let me know if you have any other questions regrding the matter! Kind Regards, Nik ---
**Author:** ![devops17](https://sea1.discourse-cdn.com/auth0/user_avatar/community.auth0.com/devops17/32/70868_2.png) [@devops17](https://community.auth0.com/u/devops17)\ **Post date:** [April 1, 2025, 6:57am UTC](https://community.auth0.com/t/auth0-integration-on-an-existing-project-on-vercel/184783/4 "2025-04-01T06:57:02Z")
Hello , The links are not that useful for me at this stage the issue what i am facing is , we have integrated auth0 - sign in and sign up is working very prefectly even in the Auth0- Monitioring and logs i am getting success message . The issue what i am facing is after sign in it doesnt redirect to my dashboard and gives a 400 error. I want help with that . ---
**Author:** ![devops17](https://sea1.discourse-cdn.com/auth0/user_avatar/community.auth0.com/devops17/32/70868_2.png) [@devops17](https://community.auth0.com/u/devops17)\ **Post date:** [April 1, 2025, 7:32am UTC](https://community.auth0.com/t/auth0-integration-on-an-existing-project-on-vercel/184783/5 "2025-04-01T07:32:42Z")
it appears that you application does not have configured the baseURL which would be either the `AUTH0_ISSUER_BASE_URL` or `AUTH0_BASE_URL` . and also for this as Auth0 was installed in Vercel - These links for `AUTH0_ISSUER_BASE_URL` or `AUTH0_BASE_URL` . were there in environment varliables of the project . AUTH0\_ISSUER\_BASE\_URL - we are using the default one - [https://dev-mm](https://dev-mm) ---
**Author:** ![nik.baleca](https://sea1.discourse-cdn.com/auth0/user_avatar/community.auth0.com/nik.baleca/32/68749_2.png) [@nik.baleca](https://community.auth0.com/u/nik.baleca)\ **Post date:** [April 1, 2025, 6:41pm UTC](https://community.auth0.com/t/auth0-integration-on-an-existing-project-on-vercel/184783/6 "2025-04-01T18:41:01Z")
Hi again Could you please provide me through a DM the tenant name on which you have integrated the application with Vercel so I could take a look? Kind Regards, Nik ---
**Author:** ![system](https://global.discourse-cdn.com/auth0/original/3X/b/5/b560f266932fcce5d57f09a6595bd50518cae3f3.jpeg) [@system](https://community.auth0.com/u/system)\ **Post date:** [April 15, 2025, 6:42pm UTC](https://community.auth0.com/t/auth0-integration-on-an-existing-project-on-vercel/184783/7 "2025-04-15T18:42:01Z")
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