@open-crate/core

The framework-agnostic engine behind open-crate. Zero runtime dependencies. MIT.

It does four things:

1. A portable crate schema (the Open Crate Format) so your library isn't trapped in one app.
2. Camelot + harmonic theory — notation, conversions, and transition scoring built on the one fact that one step round the Camelot wheel is a perfect fifth (7 semitones).
3. A swappable set-generator — an interface + an open default. Bring your own algorithm.
4. Pluggable adapters for importing libraries and enriching key/BPM/metadata.

npm install @open-crate/core

Want the full reference app and import tools? Clone the repo:

git clone https://github.com/raullee/open-crate
cd open-crate
corepack pnpm install
corepack pnpm build:core

import { generateSet, planTrackCount, type Track } from "@open-crate/core";

const crate: Track[] = [
  { artist: "Gouryella", title: "Walhalla", key_camelot: "11A", bpm: 137, energy: 4 },
  { artist: "Energy 52", title: "Café Del Mar", key_camelot: "4A", bpm: 137, energy: 5 },
  // ...your collection
];

const { tracks } = planTrackCount(60, 45, 5); // 60-min set, 45s blends, ~5 min/track
const set = generateSet(crate, { count: tracks, mode: "adventurous" });

for (const step of set.steps) {
  console.log(step.track.artist, "-", step.track.title, step.transition?.label ?? "(open)");
}

Bring your own generator

The set-generation algorithm is a strategy you can replace. Implement SetGenerator, register it, select it by id:

import { registerGenerator, generateSet, type SetGenerator } from "@open-crate/core";

const mine: SetGenerator = {
  id: "my-sound",
  label: "My sound",
  generate(pool, opts) {
    // your logic: return ordered steps
    return { generator: "my-sound", steps: /* ... */ [] };
  },
};

registerGenerator(mine);
const set = generateSet(pool, { count: 12, mode: "smooth" }, "my-sound");

The maintainer keeps a personal, heavily-tuned generator private — it's just a SetGenerator that lives outside this repo. The interface is the gift; the tuning is the art. You're encouraged to do the same: fork the default, tune it to your sound, keep it yours or share it back.

API

• Schema: Track, Keyer, Crate, trackId, isTrack, OCF_VERSION
• Camelot: parseCamelot, harmonicNeighbours, areCompatible, musicalToCamelot, camelotToMusical, camelotToOpenKey, camelotRank
• Harmonic: camelotTransition -> { smoothness, tension, semitones, note }
• Generator: generateSet, registerGenerator, listGenerators, greedyHarmonicGenerator, defaultEnergyArc, types SetGenerator / GenerateOptions / GeneratedSet
• Adapters: csvAdapter, parseCsv, interfaces ImportAdapter / EnrichmentProvider
• Crate ops: planTrackCount, setRuntimeMin, mergeTracks, leaderboard, crateStats, recentlyAdded

MIT © open-crate contributors