Custom OIDC Token Audiences

Vercel's OIDC issuer () now supports custom audiences. Deployments can request OIDC tokens with a specific audience claim, enabling secure service-to-service authentication with third-party providers.oidc.vercel.com

Vercel OIDC tokens are issued with a fixed audience (). While most cloud providers don't require a specific audience value, using a unique audience per provider is a security best practice. If a provider is compromised, an attacker cannot replay the token against a different provider - the mismatched claim will cause verification to fail. This new service makes it easy to mint provider-specific tokens without managing additional infrastructure.https://vercel.com/{owner}aud

When a Vercel deployment runs, it receives an OIDC token signed by Vercel. The new exchange service accepts this token and returns a new one signed with the same key, but with an updated audience () claim targeting your downstream service.aud

The exchanged token:

You can optionally pass a (JWT ID) to assign a unique identifier to the exchanged token. This is useful for auditing and tracing token usage across services - for example, correlating a specific token exchange with downstream API calls in your logs.jti

Downstream services verify the exchanged token using the public key available at .https://oidc.vercel.com/{owner}/.well-known/jwks

Both the signing key and the token exchange endpoint are replicated across all , ensuring low-latency token exchange regardless of where the deployment is running.Vercel regions

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Why custom audiences?

How it works

• Preserves all original claims (project, environment, owner, expiration)

• Sets the (issuer) to , scoped to the team that owns the deploymentisshttps://oidc.vercel.com/{owner}

• Includes an (actor) claim with the original token's audience and issued-at time, providing an auditable delegation chainact

• Updates the to the requested downstream audienceaud

• Updates the (issued-at) to the current timestamp, reflecting when the new token was creatediat