A Vercel app can accept a file upload and store the object in Amazon S3 without putting a long-lived AWS access key in source code or deployment variables. Vercel’s Amazon S3 Marketplace integration now connects an S3 resource to a Vercel project, supplies connection details as environment variables, and authenticates with short-lived OIDC credentials. The practical work remains yours: authorize the uploader, choose the object key, validate the file, and decide who can read it. This guide wal...