Event log
A timeline of things that happened: places, purchases, trips, deploys. My apps and AI assistants write to it, and I can ask it what we did last spring.
My knowledge graph holds what I know. This holds what happened, and when: places, purchases, trips, deploys. Things get added, rarely changed, and kept forever.
Each event has a kind and a time, and the time is only as precise as I know it: "last July" is stored as a month, not as a made-up date. A trip is one event with an end, and the places visited along the way go under it. Events also link to the people, places and projects in my knowledge graph.
A lot of it writes itself. Home Assistant logs what the house does, my GitHub Actions workflows log each deploy, and a Claude Code mod logs each coding session and its commits. For the rest, there's a web app with a timeline and a quick add, and an MCP server (MCP is the protocol AI assistants use to call outside tools). So I can ask an AI assistant "what did we do last summer?" and it answers from the log.