How HN: Agent-brain – Notes-agnostic second-brain operating model for AI agents

Agent-brain is a personal operating model for AI coding agents (Claude Code, OpenCode, Codex, Antigravity CLI) that provides a second-brain knowledge structure (journal, WIP, memory, tasks) built on top of any folder of notes, with Obsidian as one option rather than a requirement. It keeps runtime config and memory in a git-tracked brain symlinked into each runtime, adds a session lifecycle driven by the brain skill, and offers an opt-in boyscout skill for routing improvement opportunities to a remediation workflow or backlog. It installs via a curl bootstrap script that dry-runs by default and requires Python 3.x, git, and at least one supported agent runtime.