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Copy recordings from a USB voice recorder to your NAS automatically on a Mac

Plug in the recorder and every recording lands on your NAS, checked byte for byte, with the recorder cleared and ejected. A manifest file makes it easy to feed a transcription pipeline.

How it works

Most voice recorders show up as a USB drive when you plug them in. velcro recognizes yours by its volume UUID and, each time it’s plugged in:

1. Copies every recording (WAV, MP3, M4A, and other types you choose) to a folder on your NAS.
2. Reads each copy back from the NAS and compares its size and SHA-256 with the original.
3. Deletes the recordings from the recorder only if every file matched. If any file didn’t, nothing is deleted.
4. Ejects the recorder and shows a notification like “Imported 3 recordings (95 min)”.

If the NAS share isn’t attached, recordings are checked into a folder on your Mac first and moved to the NAS (and checked again) once it’s back. A file that’s already on the NAS with the same contents is skipped; a different file with the same name is saved as name-2.WAV.

Set it up

curl -fsSL https://velcro.dgit.co/install | sh
velcro recorder add                                  # with the recorder plugged in
velcro set import.dest /Volumes/home/recordings      # a folder on a share

Or use the velcro menu: Register Recorder, then pick the folder in Settings › Import. Turn off “Delete from the recorder” if you want to keep a copy on the device.

Feeding a transcription pipeline

Every imported file is appended to .velcro-import.jsonl in the destination folder, one JSON object per line:

{"file":"20260105093000.WAV","size":115200512,"sha256":"3a7f…","imported_at":"2026-01-05T11:02:41+09:00","device":"RECORDER","device_uuid":"…","original":"20260105093000.WAV","duration_s":3600.0}

A server that mounts the same NAS can watch that file for new lines, check the SHA-256 before using a recording, and run speech-to-text on it. Files only appear under their final name after they’ve been verified, so a watcher never sees half a file.

Questions

Which voice recorders work?
Any recorder that appears as a drive in Finder when plugged in over USB, which covers most dictation and meeting recorders.

Can I import to a folder on my Mac instead of a NAS?
Yes. Set import.dest to any folder. The NAS queue only kicks in for folders under /Volumes whose share isn’t mounted.