It’s almost always “this request isn’t allowed to use AI Gateway”, not “your model provider key is wrong”. Since you already tried new payment method + new API key, the most likely buckets are wrong credential/scope, feature/plan/enablement, or an account/network restriction.

Please run request that prints response headers so that you can grab req ID.

curl -i “$AI_GATEWAY_BASE_URL/v1/models” -H “Authorization: Bearer $AI_GATEWAY_KEY”

Then paste the response headers so I can tell you something.

Thanks for the guidance. I ran the curl command and captured the output.

Request ID: sin1::fra1::px78m-1773649643335-8826b1d38a61

Response Headers:

1
Date: Mon, 16 Mar 2026 08:27:23 GMT
2
Server: Vercel
3
Strict-Transport-Security: max-age=63072000; includeSubDomains; preload
4
Vary: rsc, next-router-state-tree, next-router-prefetch, next-router-segment-prefetch
5
X-Matched-Path: /v1/models
6
X-Vercel-Cache: BYPASS
7
X-Vercel-Id: sin1::fra1::px78m-1773649643335-8826b1d38a61
8
Transfer-Encoding: chunked

Good, those headers suggest your curl request didn’t hit the AI gateway API, but instead hit a next.js app/route on vercel. I think that usually happens when the base url is wrong.

so please go to vercel dashboard, AI/Gateway and copy the Gateway Base URL.

Then run this command again.

curl -i “https:///v1/models” -H “Authorization: Bearer ”

Here are the full request/response details as requested:

Request: POST https://ai-gateway.vercel.sh/v1/chat/completions

Request Headers: Authorization: Bearer Content-Type: application/json Accept: / Accept-Encoding: gzip, deflate, br User-Agent: PostmanRuntime-ApipostRuntime/1.1.0 Connection: keep-alive Cache-Control: no-cache Host: ai-gateway.vercel.sh Content-Length: 136

Response Headers: Cache-Control: public, max-age=0, must-revalidate Content-Encoding: br Content-Type: application/json Date: Mon, 16 Mar 2026 09:41:18 GMT Server: Vercel Strict-Transport-Security: max-age=63072000; includeSubDomains; preload Vary: rsc, next-router-state-tree, next-router-prefetch, next-router-segment-prefetch X-Matched-Path: /v1/chat/completions X-Vercel-Cache: MISS X-Vercel-Id: sin1::fra1::mr2nm-1773654078302-80a62b52517d Transfer-Encoding: chunked

Response Body: { "error": { "message": "Forbidden.", "type": "access_denied" } }

The response still shows Next.js headers (Vary: rsc, X-Matched-Path) and returns 403 Forbidden.

Hi @sboxm, welcome to the Vercel Community!

Sorry that you're facing this issue. I've found the issue with your account and fixing it. It might take a few hours but I'll keep you posted here.

Hi @sboxm, I've patched this for you. Can you give it a try and confirm the fix?

Hi, I just tested it and can confirm the fix works. The API is now responding correctly.

Thanks for the quick patch!