Blob URL signing via Vercel CLI

You can now generate signed URLs for Vercel Blob directly from the Vercel CLI. A signed URL is a scoped URL with a set expiration time that lets you perform a single operation on a specific object. Each URL is scoped to one operation (get, head, put, or delete), one pathname, and a custom expiry of up to 7 days. Update the Vercel CLI to version 5.14.5 to get started.

Generate a presigned URL in one command

Use the new vercel blob presign command to sign a URL for a single operation, for example to provide short-lived access to a private file or to allow your users to upload images of a certain size and content type. By default it issues a signed GET URL:

vercel blob presign media/photo.jpg --access private

Scope it to an upload with content-type and size constraints

vercel blob presign uploads/image.jpg --access private --operation put --allowed-content-type image/* --maximum-size-in-bytes 10485760

Control how long the URL stays valid with --valid-for (for example 15m, 1h, 7d) or an absolute --valid-until timestamp. Pass --json to get the result, operation, and expiry as structured output for scripting.

Issue a standalone signed token

Use vercel blob signed-token when you want to separate signed token generation from URL generation, for example to restrict write access to your private blob store while your agent investigates an issue.

vercel blob signed-token --pathname media/photo.jpg --operation get
vercel blob signed-token --operation put --allowed-content-type image/* --maximum-size-in-bytes 10485760

You can then feed the resulting delegation and client-signing tokens into vercel blob presign:

vercel blob presign uploads/image.jpg --access private --operation put --delegation-token <delegationToken> --client-signing-token <clientSigningToken>

Update to the latest version of the Vercel CLI and run vercel blob presign --help to see all available options. Learn more about signed URLs for Vercel Blob in the documentation.