Private External Integration installation route returns 404 for owner team

We need Vercel engineering assistance with a Private External Integration whose documented installation route returns Vercel's soft 404 even for the owner team.

Integration

Name: JUTARIZZ Technical Publisher
Slug: jutarizz-technical-publisher
Type: External / Connectable Integration
Visibility: Private
Owner team: jutarizz2450-1049's projects
Owner team ID: team_wWBggtCdBejxCPcl02QrknTZ

Problem

Vercel Support advised us to initiate the Private integration using:

https://vercel.com/integrations/jutarizz-technical-publisher/new

and confirmed that an externally generated opaque CSRF state can be supplied as:

https://vercel.com/integrations/jutarizz-technical-publisher/new?state=<OPAQUE_STATE>

However, this route continues to return Vercel's 404 page while authenticated to the owner team.

We also confirmed:

The integration exists in the Integration Console.
Visibility is Private.
The correct team owns the integration.
Redirect URL is configured.
Required EULA, Privacy Policy and featured image are configured.
The public Marketplace 404 is expected for a Private integration.
Searching External Integrations from the owner team's Marketplace does not expose the integration.
There is therefore no Connect, Install or Authorize action available to the owner.

A state-free diagnostic request was internally resolved by Vercel to:

/marketplace/external/[slug]/new

but Vercel served its soft-404 page.

Diagnostic request ID: syd1::jz96w-1787366579372-6a9b162cc29d

Timestamp: 2026-08-22T02:42:59.424Z

We have deliberately not changed the integration to Public and do not want to weaken our OAuth/CSRF protections as a workaround.

Could a Vercel Marketplace/Integrations engineer please verify whether this Private External Integration is missing an installation-availability, approval/publication, migration, or other provider-side state?

Specifically, we need to know why the documented /integrations/<slug>/new installation route is returning 404 to the integration's owner team, and what Vercel-side action is required to make the Private installation flow available.

No OAuth installation has been authorized and no OAuth token has been created.

There's another community post with 404 debugging tips that might be helpful. Please give these solutions a try and let us know how it goes.

https://community.vercel.com/t/debugging-404-errors/437

Vercel Community

Debugging 404 Errors

Sometimes things don’t go as expected when deploying a website. If you see a 404 on your site, that means the page or resource couldn’t be found. There are...

A human should be around soon to offer more advice. But you can also get helpful information quickly by asking v0.

reply to #2

I found a previous Vercel Community case involving the same External Integration installation route:

“404 on External Integration Install Flow (/integrations/:slug/new)”

In that case, Vercel Staff confirmed:

“A fix has been made by our engineering team and it should be working normally now.”

The original poster subsequently confirmed the issue was resolved.

Our current failure is likewise occurring on Vercel's own /integrations/:slug/new installation flow, not on one of our application's deployed routes.

Could Vercel Staff please escalate this to the Marketplace/Integrations engineering team and check whether the same provider-side issue has recurred, or whether our Private External Integration is missing an installation-availability/provider-side state?

We do not want to modify our production application, OAuth/CSRF implementation, or change the integration from Private as a workaround.

Follow-up — requesting human Marketplace/Integrations engineering review

This issue remains unresolved after 9 days.

We have now completed further production diagnostics and confirmed that the failure occurs on Vercel's own Private External Integration installation route, before our application receives an OAuth callback.

Integration: JUTARIZZ Technical Publisher Slug: jutarizz-technical-publisher Owner team: team_wWBggtCdBejxCPcl02QrknTZ

The Integration exists and is Private, but the authenticated owner-team installation route continues to return Vercel's 404 page.

We have also confirmed that our production application cannot safely substitute a project-scoped API key for the required Vercel REST deployment authority.

Please escalate this case to Marketplace/Integrations Engineering and confirm whether provider-side installation availability needs to be enabled for this Private External Integration.

The automated 404 troubleshooting guidance previously supplied does not address this issue. This is not a 404 from one of our deployed application routes.

If this Private External Integration configuration is no longer supported for installation, please confirm that explicitly so we can redesign the deployment architecture rather than continue waiting for an unavailable installation flow.

Thank you, Jay JUTARIZZ / FlowOS

Vercel Staff

Hey . I checked with the Marketplace team and they let me know the address should be https://vercel.com/<team-slug>/~/integrations/<slug>

So in your case the path to install should look like /jutarizz2450-1049s-projects/~/integrations/jutarizz-technical-publisher based on the details you shared above