What runs on your Mac

"AI-powered DJ tools" usually means a cloud service listening to your files. Metamix is the opposite, so it's worth being specific about what actually runs on your Mac.

Native analysis

Rhythm, structure, loudness, and pace come from Apple's native audio analysis frameworks, accelerated on the Neural Engine and with vDSP. That's how Metamix targets warm-cache analysis in under two seconds per track — and why it needs macOS 27 on Apple Silicon.

Per-bar DSP detail — sub-bass energy for drop detection, spectral features, waveform peaks — is computed with Accelerate. Nothing is uploaded to do it.

Local tagging

Genre, subgenre, and mood tags come from a local tagging model (AllMusicCaps) that downloads once, runs offline, and writes explainable tags: every tag carries the rule and evidence that produced it. It is not a black box, and it is not a subscription service either.

What never happens

• Your audio is never uploaded anywhere.
• There is no account, no login, no tracking profile.
• Usage analytics, when they arrive, will be opt-in and aggregate-only.

Local-first isn't a feature you bolt on at the end. It's the reason the whole thing is shaped the way it is.