Vercel AI Gateway HTTP 403 in v0 Preview — OIDC Authentication Issue - Help

Vercel AI Gateway HTTP 403 in v0 Preview — OIDC Authentication Issue - Help - Vercel Community

I'm building a Next.js application in v0 that uses Vercel AI Gateway to generate AI content.

My requests repeatedly fail with HTTP 502 at the application level. After implementing sanitized diagnostics, I confirmed that the underlying error reports HTTP 403, categorized as upstream_http_error.

Environment

Vercel Hobby plan
v0 development preview
Vercel AI SDK generateText
Model: alibaba/qwen-3-14b
Platform-injected Vercel OIDC authentication
maxRetries: 0

What I've already verified

AI Gateway integration is connected.
The model is listed in the public Gateway catalog and is eligible for free AI Gateway credit.
Both the Model Allowlist and Provider Allowlist are disabled.
The preview's decoded OIDC claims identify the expected team and project.
The token was not expired when inspected.
AI Gateway Logs show no requests for the checked time period.
AI Gateway spending shows no recorded usage.
Automated tests and the application build pass.

The application has made multiple unsuccessful generation attempts, and no messages were saved.

My question

What could cause AI Gateway to return HTTP 403 before a request appears in Gateway Logs? Is there a known OIDC authorization, Hobby-plan free-credit, or Gateway admission requirement that I should check?

Is there a secure way to obtain the specific reason for the rejection without making repeated paid AI requests?

Any guidance would be appreciated. I'm trying to resolve this without upgrading my plan or purchasing additional credits unnecessarily.

Update: AI Gateway HTTP 403 — Additional Diagnostics Completed

I've completed additional troubleshooting of my Emotional Finder — POD Launch Studio app and wanted to share the results.

Confirmed findings:

AI SDK: ai@7.0.171, using generateText({ model: 'alibaba/qwen-3-14b' }) through the default AI Gateway provider.
Original failure: AI message generation returned an upstream HTTP 403, surfaced by the application as HTTP 502.
Successful authentication check: A single authenticated GET https://ai-gateway.vercel.sh/v1/credits request from my signed-in v0 App Preview returned HTTP 200, category ok.
Gateway logs: No matching inference requests appeared in the OutHouse Gen X team's AI Gateway Logs when reviewing the last 7 and 30 days.
Project verification: The correct Vercel project is emotional-finder-pod-launch-studio (prj_US6A96fqDJlK9Xd3GU2hM5mzCvVu).
Model availability: alibaba/qwen-3-14b is listed in the current Gateway model catalog, with DeepInfra as an available provider endpoint.
Configuration: Model and provider allowlists were disabled, and the current routing-rules list is empty.

The credits check confirms that the preview's OIDC credential worked for that endpoint, but it does not establish whether model inference uses the same authentication context.

Could the Vercel team help clarify:

Whether the AI SDK's default Gateway provider uses the same OIDC credential and project context as an explicit authenticated credits request in a v0 Preview.
Whether inference requests rejected before normal Gateway processing would appear in AI Gateway Logs.
How to identify the rejecting layer when an inference request returns HTTP 403 but no Gateway request ID or corresponding log entry is available.
Whether there is a recommended way to verify the preview deployment's inference authentication without repeatedly submitting paid model-generation requests.

I have not changed credentials, project links, billing settings, or deployment configuration, and I have not made another inference request.

Thank you for any guidance on identifying the source of this HTTP 403.