Agent-brain: A Notes-Agnostic Second-Brain Operating Model for AI Coding Agents

Agent-brain is a personal operating model for AI coding agents such as Claude Code, OpenCode, Codex and Antigravity CLI, built on a second-brain structure of journal, WIP, memory and tasks that works over any folder of notes, with Obsidian optional. Runtime config and memory like CLAUDE.md and AGENTS.md are kept in a git-tracked brain and symlinked into each runtime, so setup travels across machines. Install runs via curl and dry-runs by default, with a session lifecycle driven by the brain skill.