A safe crossing, step by step.

Run Bro from anywhere

Bro 0.4.0 is beta software. Send feedback if Bro encounters a filesystem or network condition its test suite has not covered.

Do not use Bro with mission-critical data. Keep an independent copy until you have verified the transfer or successfully restored the backup. Bro must never be the only copy of irreplaceable data during beta.

Start a copy or safe move

1. Choose one or more files, choose a folder, or drag source items onto Bro.
2. Choose the destination folder.
3. Select Copy, Move safely, or Verify & Repair.
4. Optionally choose full speed, low-impact network speed, or a custom limit.
5. Choose Start Copy or Start Safe Move.

If an item with the same name already exists at the destination, Bro creates a clear Bro Copy name instead of replacing it.

Verify and repair an existing copy

Choose the original source and the folder that already contains its destination copy, then select Verify & Repair. Bro compares every file through its SHA-256 manifest and transfers only missing or different data. It does not create a second collision copy.

Create a Backup / Archive

1. Select Backup / Archive.
2. Choose one file or folder to archive.
3. Choose a folder on your Mac for the verified local archive set.
4. Choose the final backup destination, such as an external drive or mounted NAS share.
5. Enter the volume size and choose MB or GB. Any value of at least 1 MB is accepted.
6. Choose Start Backup.

Bro uses Apple Archive with LZFSE compression and preserves the original folder structure, symbolic links, extended attributes, permissions, access controls, dates, and sparse data supported by macOS. It streams the archive into numbered .brovol files. Every non-final volume uses the exact size you requested.

What happens during a backup

1. Bro inventories and hashes the source.
2. It creates size-limited archive volumes in a hidden local staging folder.
3. It confirms the source did not change, commits the local .brobackup folder, and verifies every volume.
4. It copies the set resumably to hidden destination staging.
5. It reads back every destination volume, checks its SHA-256 digest and the combined stream digest, then reveals the final backup set.

If power is lost while the local archive is being created, Bro safely rebuilds that incomplete local stage. If interruption occurs while volumes are crossing the network, the partial destination data remains and rsync continues it after Bro relaunches.

Restore an entire backup

1. Choose File → Restore Bro Backup…, or select Backup / Archive and choose Restore Backup….
2. Select the .brobackup folder or its Bro Backup.json manifest.
3. Choose a restore destination.

That one action reads every numbered volume in order. Before extraction, Bro verifies each volume and the combined archive stream. It restores into a hidden staging folder, independently hashes every restored file against the original manifest, and reveals the final result only after the complete check passes.

Start a two-way Sync

1. Select Sync.
2. Choose exactly one directory as Folder A.
3. Choose a different, non-nested directory as Folder B.
4. Optionally choose a network speed limit.
5. Choose Start Sync.

Bro inventories and hashes both folders. Items found only in Folder A are copied to Folder B, and items found only in Folder B are copied to Folder A. Identical items are skipped. Bro verifies the final union independently before saying the Sync is complete.

Resolve different versions

When the same relative path exists on both sides but the file data, symbolic-link target, item type, Finder metadata, permissions, or access controls differ, Bro stops and asks what to keep:

• Keep Folder A copies Folder A’s version to Folder B.
• Keep Folder B copies Folder B’s version to Folder A.
• Keep Both keeps Folder A under the original name and adds Folder B’s version to both folders with — from Folder B in its name.

Choose per item or apply one choice to all current conflicts. Choices are saved immediately and survive a quit, restart, or power loss. If either version changes before Bro commits it, the stale choice is discarded and the changed conflict is presented again.

What happens before a Sync replacement

Bro never destroys the losing version in place. It first moves that version into a hidden .bro-sync-recovery-… folder on the same volume, commits the verified winner, and records the recovery location in Sync Details and the final report.

Recovery archives remain after a successful Sync so you can inspect or remove them later. Bro excludes its own recovery and staging folders from future Sync comparisons.

Renames, deletions, packages, and filesystem limits

• A rename made on only one side appears as one missing old name and one missing new name. Non-destructive Sync keeps both names in both folders.
• A file deleted on only one side is restored from the other side.
• Folders and Mac packages are compared through their complete relative contents; empty folders are retained.
• Case or Unicode names that cannot coexist on either filesystem stop the Sync before copying.
• Symbolic links are preserved when both filesystems support them. An incapable destination is rejected with a clear explanation.
• Hard links and sparse allocation are preserved when supported. On an incapable destination, file data remains exact and the report names the metadata limitation.
• Sockets, devices, and other special filesystem objects are not copied; Bro stops safely without altering either source.

Read the Sync report

A completed Sync creates a readable report under ~/Library/Application Support/Bro/Sync Reports. It lists additions and updates for Folder A and Folder B, conflicts found and resolved, Keep Both copies, identical items skipped, folders created, bytes copied, safety replans, metadata warnings, and every recovery location.

Select the job, choose Details, then choose Reveal Sync Report.

Copy or move safely?

Copy leaves the source in place after the destination is checksum verified. Move safely performs that same copy and verification first, then removes only source items that have not changed in the meantime.

Pause and resume

Select an active transfer and choose Pause. Bro asks its bundled rsync helper to stop cleanly and retains the hidden staging data. Select the job later and choose Resume.

You can also reopen Bro after a restart or power loss. Any job that was active is marked Interrupted and offered for resumption. Bro continues against the same fixed destination rather than creating a second copy. The final destination name does not appear until verification succeeds.

What verification means

Bro creates a per-file SHA-256 source manifest, independently hashes the staged destination, and checks the complete file list. If the source changes during the crossing, Bro copies the changed data again. If the destination differs, Bro automatically repairs and reverifies it.

A transfer says Verified only after that comparison finishes successfully.

If a drive disconnects

• Reconnect or remount the same destination drive or network share.
• Confirm it appears at the same folder path used by the job.
• Bro confirms the recorded volume identity and resumes automatically.
• You can still select the waiting job and choose Resume.
• Do not rename a partial Bro destination while its job is unfinished.

Bro preserves its job record if the destination is unavailable; it does not redirect the transfer somewhere else.

Repeat, save, or schedule a transfer

Use Repeat to refill the controls from a previous job, save the current source and destination—or Folder A and Folder B—as a preset, or add a one-time or daily schedule. Because Bro remains portable and installs no background service, schedules run while Bro is open. Missed work is checked the next time Bro opens.

Receipts, details, and diagnostics

Select a job and choose Details to see its preflight, destination identity, current file, file and byte totals, repair passes, archive volumes, and SHA-256 manifest. Finished transfers receive a readable receipt; finished Syncs receive the more detailed Sync report. If help is needed, export a privacy-safe diagnostic ZIP; full source and destination paths are replaced by short fingerprints.

Files that change during a move

Bro records the verified source state before cleanup. If a file changes after verification, or a new file appears in the source folder, Bro leaves that item behind. The verified destination remains intact and the transfer explains what it preserved.

Permissions and protected folders

macOS may ask for permission when Bro first touches protected folders, external volumes, or network storage. Grant only the access needed for the transfer. Bro does not need Full Disk Access for ordinary files you choose through its file panels.

Check for updates

Choose Bro → Check for Updates…. Bro reads a small version file from this website and never downloads or replaces the app automatically. It compares both the version and build number.

Where Bro keeps its records

Transfer history, two checksummed recovery-journal generations, SHA-256 manifests, Sync plans, archive job records, receipts, Sync reports, and bounded diagnostic logs remain under ~/Library/Application Support/Bro. Moving Bro.app itself does not move or erase those records.

Roadmap

Direct cloud-provider support through rclone is planned for a future version. The current Bro beta deliberately focuses on local folders, external drives, and network storage already mounted in Finder.