Build a Next.js file uploader with Cloudflare R2
Signed-in users upload from a Next.js app straight to a private R2 bucket with progress, then download only their own files through short-lived signed URLs.
Read the guideBuild the whole thing.
The docs cover each method, adapter, and component on its own. Each guide here connects them into one working storage feature, from the bucket's setup to the browser, and says plainly where a provider can't do what you need.
Uploads
Upload files in TanStack Start with server routes and streaming
A TanStack Start server route that sends uploads straight from the browser to S3 under a size-capped POST policy, or streams them through your server.
Read the guideEnforce file-size and content-type limits on presigned uploads
What S3, R2, Vercel Blob, GCS, and Azure check when the browser uploads to a signed URL, and how to verify the actual bytes when the signature can't.
Read the guideResume an S3 multipart upload after a process restart
A Node or Bun uploader that saves its S3 multipart session to disk, survives a crash or Ctrl-C, and finishes from the parts S3 already holds.
Read the guideBuild a shadcn file manager with uploads, folders, previews, and progress
One page of Files SDK shadcn components that browses folders, uploads into them with progress, previews files, pages long folders, and retries failures.
Read the guide
Downloads and access
Share private Vercel Blob files with authenticated, expiring downloads
Invoice PDFs in a private Vercel Blob store that each customer can download only for themselves, and when to redirect to signed URLs or proxy instead.
Read the guideStream private video from S3 or R2 with HTTP Range requests
A Next.js video player for private S3 or R2 objects that seeks with 206 range responses, using signed URLs or a session-checked proxy route.
Read the guideIsolate each tenant's files in a multi-tenant application
Keep two tenants in one bucket apart with server-derived key prefixes, and see exactly what the gateway returns when one tenant reaches for the other's files.
Read the guide
AI
Add persistent, private file attachments to an AI SDK chat app
Users attach images and PDFs to an AI SDK 7 chat. Files stay in a private bucket, and each message stores only a key that is re-authorized on every read.
Read the guideGive an AI SDK agent access to S3 or R2 with approval-gated storage tools
An AI SDK 7 agent lists, reads, and proposes changes to one user's files in S3 or R2, and every write waits until the user approves it in the chat.
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Providers and runtimes
Set up Vercel Blob authentication: OIDC, local development, and token fallback
Which credential the files-sdk Vercel Blob adapter uses on Vercel Functions, in local development, and on other hosts, and how to fix each setup error.
Read the guideUpload files to S3 with Bun: native S3Client, presigned URLs, and SDK tradeoffs
One Bun file server written twice, with Bun's own S3Client and with Files SDK, covering browser uploads and when to move to the s3() adapter instead.
Read the guideUse R2 in Cloudflare Workers: bindings, the S3 API, and presigned uploads
A Worker that reads and writes R2 through its binding, signs presigned URLs with an R2 API token, and lets browsers upload straight to the bucket.
Read the guideUse Hetzner Object Storage from TypeScript: endpoints, uploads, and signed URLs
Connect TypeScript to a Hetzner bucket in fsn1, nbg1, or hel1, upload files, share private ones through signed URLs, and set the CORS rule browser uploads need.
Read the guideUpload and privately share files on Wasabi with TypeScript
Store documents in a private Wasabi bucket, verify each upload, and share them through expiring links you can revoke, with the endpoint for every region.
Read the guideUpload files to Bunny Storage and serve them through a Pull Zone
Stream browser uploads through your server into a Bunny Storage zone, serve them from your Pull Zone hostname, and purge the edge cache when a file changes.
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Architecture and migration
Build one TypeScript storage API for S3, GCS, Azure, and Dropbox
One storage module that picks S3, Google Cloud Storage, Azure Blob, or Dropbox from config, runs the same code on each, and branches on what each can do.
Read the guideMigrate S3 files to R2 and verify the result
Copy an S3 bucket to Cloudflare R2 with a script that records failures, retries only those keys, checks every object by checksum, and plans a rollback.
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Troubleshooting
Fix Vercel's 413 upload error with direct-to-storage uploads
Stop FUNCTION_PAYLOAD_TOO_LARGE by signing uploads in a small Vercel Function request and sending the file from the browser straight to Vercel Blob or R2.
Read the guideFix Cloudflare R2 CORS and presigned URL 403 errors
Tell a CORS rule problem from a rejected signature when browser uploads to R2 fail, and fix each cause, from origin mismatches to expired presigned URLs.
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Ship the storage layer once.
Open source, MIT licensed, and built on web standards.
Pick an adapter today and change your mind whenever you like.