Upload SDK is an open-source, TypeScript-first SDK for building secure direct file uploads to AWS S3 and ImageKit.

It lets you define reusable, type-safe upload assets with rules for file size, MIME type, extension, expiry, storage destination, and key structure. Your server validates the upload request and generates a short-lived signed multipart POST target, while the browser uploads the file directly to the storage provider.

Upload SDK also supports multiple storage profiles, making it easy to use different buckets, regions, accounts, credentials, or providers within the same application while keeping the upload flow consistent.

File bytes never pass through your application server, credentials remain server-side, and supported restrictions can also be enforced by the storage provider during the upload.

Key features include:

• Direct browser-to-provider uploads
• Type-safe named upload assets
• Multiple S3 and ImageKit configurations
• MIME type, extension, size, and expiry rules
• Short-lived signed upload targets
• Collision-resistant file keys
• Provider-enforced upload restrictions
• One consistent prepareUpload() API across providers

Upload SDK reduces the amount of custom upload infrastructure you need to build while keeping storage configuration, validation, and security rules organised.