Ableton Library

The problem

A decade of Ableton Live projects is a pile of opaque folders. Finding “that 150 BPM idea with the Korg patch” means opening projects one at a time in Live — minutes each. There’s no official SDK and no spec for the .als format; the only honest way in is to read the files themselves.

What I built

A Rust toolchain over one catalog: an ableton-scan CLI and a Tauri desktop app. Scanning recurses any folder structure, parses every .als (a gzipped XML document) without touching Ableton, and indexes Live version, tempo, time signature, tracks, devices and plugins, referenced samples, and locators into SQLite with FTS5 — so a query like search --min-bpm 140 --max-bpm 160 --plugin soothe is answered by the index instead of by opening projects one at a time. On top of the catalog: waveform previews, lists and favorites, artist filing, and a 3D similarity map of every set in the library.

The hard parts

Parsing without a spec. Real libraries contain corrupt files, version drift across a decade of Live releases, and half-missing metadata. Extraction is lenient by design: a missing field becomes a warning on that set, a corrupt file logs an error and the scan continues. One bad project never aborts a scan, and rescans are incremental — only changed files are re-parsed.

Previews from three sources. A project isn’t listenable until something renders it. The app harvests bounces it discovers near projects, runs an automated render worker that drives a real Live install through UI automation, and falls back to a no-Ableton approximate “sketch” render. A triage scorer reports each set’s renderability (missing plugins, missing samples → a 0–1 score) so the worker spends time only where a render will actually succeed.

Metadata that survives rebuilds. Artist attribution is derived from folder paths via marker and positional heuristics, with hand-tags that stick through rescans. Lists are keyed by file path rather than database row, so favorites survive a full catalog rebuild — the catalog is disposable, the library isn’t.