Built the macOS way

PicoOSS uses Apple's native frameworks throughout — no third-party runtime, no embedded browser.

Three-pane native layout

Accounts and buckets on the left, objects in the middle, details in the inspector — built on NavigationSplitView so it behaves like a Mac app should.

Credentials stay in your Keychain

Each account's AccessKey ID, secret and optional STS token are stored as separate entries in the macOS Keychain. Secrets are used locally to sign requests.

OSS V4 request signing

Signing is implemented locally with CryptoKit (HMAC-SHA256). Your AccessKey secret is never sent as a request field.

Drag, drop and upload folders

Drop files or whole folders from the Finder. Large files switch to OSS Multipart Upload, and you control how many transfers run at once.

Quick Look previews

Press the space bar to preview images, video, audio, PDFs and documents without downloading them permanently. Previews use a bounded local disk cache.

Share links and QR codes

Generate OSS V4 presigned download URLs and QR codes locally. Anyone holding the link can open the object until it expires or permissions change.

Your data, your account

PicoOSS is a client, not a service. There is no PicoOSS account, no file relay and no developer-operated backend. Requests travel directly from your Mac to the OSS endpoint you configure, authenticated with credentials only you hold.

The app ships without analytics, advertising or third-party crash-reporting SDKs. Because OSS requests carry your account and object information to the endpoint you choose, please read the privacy policy for the details of what is stored locally and what is sent to your cloud provider.

Read the privacy policy