FlowClone

Move everything. Lose nothing.

FlowClone is a modern, open-source SSD migration assistant for macOS and Windows (macOS-first). It is a Tauri desktop app with a React interface, English/Thai UI support, and a Rust workspace behind it.

Tested on: MacBook (Apple M4 Max), macOS Tahoe 26.5.1.

Key features

• Smart imaging that skips the empty space. FlowClone reads only the blocks your filesystem is actually using — so a barely-filled 512 GB SSD becomes a ~50 GB image, not a 512 GB one. Quicker to capture, smaller to keep.
• One-tap compression. Shrink images even further with built-in zstd — a tiny .flowimg you can stash on any drive or in the cloud.
• Exact when it matters. Want a true bit-for-bit copy instead? Flip one switch from Smart to Exact for a full, faithful clone.
• Upgrade your SSD in two moves. Image the old drive, restore onto the new one — the painless way to jump from 256 GB to 512 GB and beyond.
• Safety wired into the core. Your source disk is never written to. Restores demand a typed ERASE and flat-out refuse boot, internal, read-only, and too-small targets — guardrails enforced in the Rust engine, not just the UI.
• Built for the real world. Loose cable? It reconnects and resumes. Bad sector? It skips and logs it instead of giving up. Power loss? The next launch flags the unfinished image so nothing silently breaks.
• Never guess what's happening. Live percentage, transfer speed, GB written, and ETA — plus a desktop notification the moment a job finishes.
• Plug and go. Drives pop in and out of the list the instant you connect or remove them, and you can safely eject straight from the card.
• Your language, your theme. English & ไทย, light & dark — switch anytime.
• Light, native, and quick. A ~7 MB Tauri + Rust download built for macOS (Apple Silicon & Intel) — no Electron bloat, no telemetry, no account.
• Free and open source. MIT-licensed — inspect it, build it, trust it.

Disclaimer

Use FlowClone entirely at your own risk. It performs low-level disk operations — reading raw devices and erasing and overwriting entire disks. A wrong disk choice, a failing drive, a flaky cable or enclosure, or an interrupted write can lead to permanent data loss or a disk you can no longer use.

FlowClone is provided "as is", without warranty of any kind. The authors and contributors accept no responsibility or liability for any data loss, file or filesystem corruption, drive or SSD failure, hardware damage, or any other loss arising from using — or being unable to use — this software (see the License).

Before you start: keep a separate, verified backup of anything you can't afford to lose, and double-check the source and target disks every time. Choosing the correct drives is your responsibility.

Safety warning

FlowClone can now create and restore raw disk images on macOS and Windows.

• Image Migration reads a source disk into a .flowimg file (read-only on the source).
• Restore Image writes a .flowimg back onto a target disk — this is destructive and erases the target.

Both need elevated raw-disk access:

• macOS — an admin prompt, plus Full Disk Access granted to the responsible app.
• Windows — a UAC prompt (Run as administrator). No separate Full Disk Access grant is needed. Restore locks and dismounts the target's volumes before writing; close anything using the target disk first.

Direct Clone is temporarily disabled in this release, and verification is still stubbed.

Features

UI shell

• First-run onboarding that walks you through granting the access FlowClone needs (macOS Full Disk Access / Windows UAC).
• Switch between English and Thai.
• Persist the selected language locally.
• Switch between light and dark mode.
• Detect disks automatically as they are connected or removed (event-driven via the native DiskArbitration watcher), with a manual refresh available.
• Eject an external disk safely from its card before unplugging.

Image Migration

• Detect the connected source SSD and show its real used space.
• Choose where to save the .flowimg image.
• Create a full raw image of the source disk. The privileged raw read runs through a native macOS admin prompt (or the flowclone CLI under sudo); the source is unmounted for the read and remounted afterward.
• Choose Smart (store only used blocks of an NTFS disk; falls back to a full copy otherwise) or Exact (full bit-for-bit copy), and optionally Compress the image — with a live size/time estimate.
• Show live progress, transfer speed, and estimated time; cancel at any time (with a confirmation prompt). A desktop notification fires when the job finishes, and closing the app mid-job asks for confirmation.
• Recover from interruptions: auto-reconnect and resume if the disk drops off the bus, skip unreadable blocks (ddrescue-style) so a bad sector doesn't abort the whole image, and flag an unfinished image on the next launch after a crash or power loss.

Restore Image

• Choose a .flowimg file and a target SSD.
• Validate the image and the target (rejects boot, internal, read-only, and too-small disks).
• Require typed ERASE confirmation.
• Write the raw image onto the target via a macOS admin prompt (or the flowclone CLI with --confirm-erase), with live progress, speed, and ETA.
• Destructive — the target disk is erased and overwritten.

Direct Clone (coming soon)

Disk-to-disk cloning is temporarily disabled in this release while Image Migration and Restore are stabilized. The mode is visible but inactive (it shows a "coming soon" tooltip) and will return in a later version.

Tech stack

• Tauri v2
• React
• TypeScript
• Vite
• Tailwind CSS
• shadcn/ui-style primitives
• Framer Motion
• Lucide Icons
• Zustand
• Rust workspace

Repository layout

flowclone/
  apps/
    desktop/
  crates/
    flowclone-core/
    flowclone-disk/
    flowclone-raw/
    flowclone-verify/
    flowclone-report/
    flowclone-cli/
  docs/
  assets/
  scripts/

Development setup

pnpm install
pnpm dev
pnpm typecheck
pnpm lint
pnpm build
pnpm test
FLOWCLONE_DISK_BACKEND=mock pnpm dev
cargo run -p flowclone-cli -- list-disks

Use FLOWCLONE_DISK_BACKEND=mock FLOWCLONE_MOCK_DISKS=one pnpm dev to test the Image Migration path.

For local raw image testing on macOS, build the CLI and run only the CLI with admin rights:

cargo build -p flowclone-cli
sudo ./target/debug/flowclone create-image --source /dev/disk6 --output ~/Downloads/FlowClone-test.flowimg

Pass --compress to create-image to write a smaller zstd-compressed .flowimg (v2 format); restore-image auto-detects and decompresses it, and still restores older uncompressed images. Pass --used-only to read and store only the allocated blocks of an NTFS disk (much faster and smaller on a mostly-empty disk); it falls back to a full image if the disk isn't GPT/NTFS. The two flags combine. The GUI exposes both via the Image Migration Smart / Exact toggle and Compress switch. See docs/SPARSE_IMAGE.md.

Do not run the desktop GUI as root.

Creating an image from the GUI triggers a macOS admin prompt for the raw read. That elevated read also needs Full Disk Access for the responsible app — grant it under System Settings → Privacy & Security → Full Disk Access. In development, grant it to the terminal that launches pnpm dev (the dev app inherits its access). The GUI runs the same flowclone CLI, so build it first with cargo build -p flowclone-cli.

Build desktop installers

Run pnpm install before any build command. pnpm tauri build runs the frontend build (tsc -b && vite build) automatically. Release artifacts are generated by Tauri under target/**/release/bundle/.

One-shot macOS release build (recommended)

For a full release, use the release script — it builds both the Apple Silicon and Intel signed DMGs and verifies them:

scripts/release-macos.sh            # build + sign + verify both DMGs
scripts/release-macos.sh --publish  # also create the GitHub release for v<version>

It handles the manual footguns: detaching a stale /Volumes/FlowClone before each build (it otherwise collides with bundle_dmg.sh), and ad-hoc signing the Intel app — which, when cross-compiled on Apple Silicon, is not signed by default and would trip Gatekeeper's "app is damaged" on Intel Macs. The Intel app is signed in place inside Tauri's DMG so the drag-to-Applications layout is preserved. --publish reads the release notes from CHANGELOG.md and needs an authenticated gh. The manual per-target steps below still work if you need one specific artifact.

Bundle the CLI sidecar first. Image Migration and Restore run the flowclone CLI for the privileged raw I/O, bundled into the app as a Tauri sidecar. Build it for the same target you pass to tauri build, otherwise the app launches but those workflows fail with "FlowClone CLI not found":

pnpm sidecar                                   # host arch
# or a specific target:
bash scripts/build-sidecar.sh aarch64-apple-darwin
bash scripts/build-sidecar.sh universal-apple-darwin   # fat binary via lipo

macOS Apple Silicon .app

Use this for M-series Macs:

bash scripts/build-sidecar.sh aarch64-apple-darwin
pnpm tauri build --target aarch64-apple-darwin --bundles app,dmg

Expected output:

target/aarch64-apple-darwin/release/bundle/macos/FlowClone.app

macOS Intel .app

Use this for Intel Macs:

bash scripts/build-sidecar.sh x86_64-apple-darwin
pnpm tauri build --target x86_64-apple-darwin --bundles app,dmg

Expected output:

target/x86_64-apple-darwin/release/bundle/macos/FlowClone.app

macOS universal .app

Use this when one .app must run on both Apple Silicon and Intel Macs:

bash scripts/build-sidecar.sh universal-apple-darwin
pnpm tauri build --target universal-apple-darwin --bundles app,dmg

Expected output:

target/universal-apple-darwin/release/bundle/macos/FlowClone.app

To create a DMG on macOS, use --bundles app,dmg instead of --bundles app. Unsigned builds may require right-clicking the app and choosing Open. Production distribution still needs Apple Developer signing and notarization.

After installing the built app:

• Grant it Full Disk Access (System Settings → Privacy & Security → Full Disk Access) so it can read/write raw disks and read images from protected folders like Downloads.
• The .flowimg document icon only appears once the app is registered with Launch Services — move it to /Applications (or run lsregister -f FlowClone.app) and restart Finder.

Windows .exe

Build Windows installers on a Windows machine or Windows CI runner. Cross-building the Windows .exe from macOS is not the supported path for this project.

Prerequisites:

• Node.js 20+
• pnpm
• Rust stable with the MSVC toolchain
• Visual Studio Build Tools with Desktop development with C++
• WebView2 Runtime for machines that do not already include it

Build the CLI sidecar (the bash script is macOS-only, so do it manually), then the NSIS .exe installer:

pnpm install
rustup target add x86_64-pc-windows-msvc
cargo build -p flowclone-cli --release --target x86_64-pc-windows-msvc
New-Item -Force -ItemType Directory apps\desktop\src-tauri\binaries | Out-Null
Copy-Item target\x86_64-pc-windows-msvc\release\flowclone.exe `
  apps\desktop\src-tauri\binaries\flowclone-x86_64-pc-windows-msvc.exe
pnpm tauri build --bundles nsis

Expected output:

target\release\bundle\nsis\FlowClone_0.3.7_x64-setup.exe

If the Windows host is not x64, install the target explicitly and pass it:

rustup target add x86_64-pc-windows-msvc
pnpm tauri build --target x86_64-pc-windows-msvc --bundles nsis

Unsigned Windows builds may trigger SmartScreen warnings. Production distribution needs Windows code signing.

Docs

• User Guide (web) — online guide with screenshots
• docs/USER_GUIDE.md — how to install and use FlowClone
• CHANGELOG.md
• docs/DESIGN.md
• docs/SPARSE_IMAGE.md — the .flowimg v2 / sparse-image design
• docs/ARCHITECTURE.md
• docs/SAFETY.md
• docs/ROADMAP.md

License

MIT. Treat this as a placeholder until the project governance is finalized.