Vercel
Native subscription authentication now lets Vercel’s AI SDK harness layer use subscriptions already available on the host. Builders can run supported coding agents without adding another set of provider credentials to the application.
According to the changelog entry, the change requires no new settings or code changes. Harnesses continue to run through the same HarnessAgent interface, so an application can switch between agents without changing its integration code.
This applies wherever the underlying harness supports subscription authentication. The harness layer checks for credentials according to its selected authentication mode.
How native subscription authentication chooses credentials
| Authentication mode | Credential behaviour |
|---|---|
auto | Uses AI Gateway credentials when configured. Without them, it uses explicit provider environment credentials when present, then a native subscription on the host. |
direct | Uses explicit provider environment credentials when present. Otherwise, it uses a native subscription found on the host. |
ai-gateway | Uses AI Gateway and never reads native subscriptions. |
Existing applications using auto or direct mode do not need to opt in. If the relevant environment credentials are already present, those credentials continue to take precedence over a native subscription.
The shared interface is also unchanged. The authentication decision happens beneath the HarnessAgent layer rather than becoming another branch in the application’s agent code.
Credentials remain on the host
Native subscription credentials are resolved at the host boundary, following the same approach used for API keys. OAuth access tokens are also refreshed on the host when needed.
Where a sandbox supports this setup, the harness receives placeholder credentials rather than the real token. Vercel injects the actual token into outbound requests at the host boundary. This keeps the subscription credential out of the sandbox while still allowing the harness to make authenticated requests.
The update follows Vercel’s work on persistent environments for agents, including its support for running the OpenAI Agents API with persistent sandboxes.
Frequently asked questions
What is native subscription authentication in Vercel?
It lets the AI SDK harness layer authenticate a supported coding harness through a subscription available on the host. The credentials stay at the host boundary rather than being passed directly into the harness.
Does native subscription authentication require code changes?
No. Existing harnesses continue to use the same HarnessAgent interface, and no new settings are required.
Which Vercel plan includes native subscription authentication?
The changelog does not list plan or pricing requirements. Availability also depends on whether the underlying harness supports native subscriptions.
Sources
3 checkedHow we cover tool news: Create With's tool desk drafts these reports with AI from the sources listed above and checks them against those sources before publishing.
n8n
ElevenLabs
Perplexity