I Built a Personal Knowledge Graph. Apple Had Already Built One on My Laptop.

I've been building a system called Nexus for the past few months. It's a personal data platform: 54 data sources, 250+ tables, 358,000 knowledge graph facts, all running in Postgres 16 on a home server. It ingests everything from iMessage to Gmail to Apple Photos to Spotify to HealthKit. The goal is biographical intelligence: a queryable model of my own life. A few weeks ago, while wiring up some of the Apple-specific data sources, I cracked open the local databases that Apple maintains on macOS