Spindle

Accurate, hands-off CD ripping for macOS.

Insert a disc — Spindle rips it accurately, tags it with MusicBrainz metadata and cover art, encodes to FLAC, ALAC, or AAC, delivers the album to a local folder or SFTP server (a Navidrome host, for example), and ejects so you can feed it the next disc.

Download

Download the latest signed, notarized .dmg from the Releases page, open it, and drag Spindle into Applications. Requires macOS 14 or later. Once installed, Spindle keeps itself up to date — it checks for new versions on launch (via Sparkle) and offers them in place.

Each release is built, signed, notarized and packaged automatically by GitHub Actions — see docs/RELEASING.md for how to cut one.

How it works

• Accurate ripping — Spindle reads raw CDDA sectors through the macOS IOKit CD ioctls with C2 error pointers. Damaged sectors are re-read until consecutive reads agree; drives without C2 fall back to read-twice-compare. Unreadable tracks are abandoned after a per-track time budget so a batch keeps moving. Per-drive read-offset correction is supported, and every rip is verified against the public CUETools Database.
• Metadata — the MusicBrainz DiscID is computed from the disc TOC and looked up on MusicBrainz (with fuzzy TOC fallback and CD-TEXT as a last resort). When several pressings match, Spindle asks you to pick — without pausing the rip. For a disc MusicBrainz doesn't know, you can hand-edit the album and per-track tags in a built-in editor, or have Spindle tag it as "Unknown" and keep going unattended — your choice in Settings. Either way only the encode waits; the rip and eject still proceed. Cover art comes from the Cover Art Archive with an iTunes fallback.
• Encoding — FLAC, ALAC, or AAC (256 kbps), one format per rip, chosen in Settings. Every format carries the full Picard-compatible tag set and embedded cover art; FLAC additionally gets a correct PCM MD5 in its STREAMINFO. Files are named by a configurable template, Artist/Album (Year)/01 - Title.flac by default. Each album folder can also receive an archival rip log, a .cue sheet, and a cover.jpg.
• Delivery — to a local folder (which covers Finder-mounted SMB/NFS NAS shares) or over SFTP. Uploads go to a .part name and are renamed on completion so library scanners never see partial files. Secrets live in the Keychain, and SSH host keys are pinned on first connect (trust-on-first-use) and verified on every later upload.

Spindle is a Developer ID app, not sandboxed: the App Store sandbox does not permit the raw drive access accurate ripping requires.

Building

Requires macOS 14+ to run and Xcode 16+ to build.

The app lives in Spindle.xcodeproj (open it and hit Run); all logic lives in the SpindleCore local Swift package.

open Spindle.xcodeproj                  # develop in Xcode
(cd SpindleCore && swift test)          # Swift Testing suite, headless
Scripts/make-app.sh                     # assemble dist/Spindle.app (Debug)
Scripts/make-app.sh release             # universal Release build

Release packaging

SIGN_IDENTITY="Developer ID Application: Your Name (TEAMID)" Scripts/make-app.sh release
Scripts/notarize.sh             # needs a notarytool keychain profile
Scripts/make-dmg.sh

Development CLI

Every subsystem is exercisable headless via spindle-cli (run from SpindleCore/):

swift run spindle-cli detect            # watch disc insertions
swift run spindle-cli toc               # print the table of contents
swift run spindle-cli discid            # MusicBrainz DiscID for the disc
swift run spindle-cli identify --pick 1 # MusicBrainz lookup (+ --toc for discless testing)
swift run spindle-cli rip --out rip     # secure rip + CTDB verification
swift run spindle-cli scan-offset rip   # find the drive's read offset via CTDB
swift run spindle-cli encode rip --toc "…" --format flac   # flac, alac, or aac
swift run spindle-cli push library --to sftp://user@host/srv/music

Architecture

Spindle.xcodeproj builds the thin SwiftUI app shell in Spindle/; the SpindleCore/ package holds everything else:

Module	Purpose
CIOCD	C shim for the IOKit CD ioctls (DKIOCCDREAD &c.)
DiscDrive	Drive monitoring (DiskArbitration), TOC parsing, raw device access
RipEngine	Secure/burst rip loop, offset correction, checksums, WAV staging
Metadata	DiscID, MusicBrainz WS/2, release scoring, Cover Art Archive, CD-TEXT
Verification	CUETools DB client and rip verdicts
Encoding	Core Audio FLAC/ALAC/AAC encoders + pure-Swift FLAC tagger
Naming	Filename templates and path sanitization
Transfer	Local-folder and SFTP destinations, Keychain
SpindleCore	The pipeline coordinator orchestrating all of the above
Spindle/ (app)	SwiftUI shell: main window, release picker, tag editor, Settings

Dependencies: Citadel (MIT) for SFTP, and Sparkle for in-app updates. Everything else is Apple frameworks.

Authorship

The vast majority of this codebase — Swift sources, tests, build scripts, CI, and this README — was written by Claude (Anthropic's LLM), working from the project's design and human direction and review. If you're reading the code, keep that in mind: treat it with the same scrutiny you'd give any machine-generated work, and please report anything that looks off.

License

© 2026 Thijs Wijnmaalen. All rights reserved (for now).