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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 /Volumes/VOICE                   # the recorder, plugged in
velcro set import.folder RECORD                      # optional: only the recordings folder
velcro set import.dest /Volumes/home/recordings      # last: importing starts once this is set

No NAS? Any folder works, like ~/Recordings, a folder on an external drive, or one in iCloud Drive. If the recorder also holds music, set import.folder to its recordings folder so nothing else on it is touched.

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.