Setup / Stack
second-brain
An open-source, self-maintaining knowledge system that turns source files and questions into a cited, interconnected Markdown wiki.
Creator2026CodexClaude CodeMarkdown
second-brain is a portable, self-maintaining knowledge system for the work you do not want to re-explain. It turns your source files and questions into a cited Markdown wiki that Codex or Claude Code can keep current.
How it works
- Start from evidence. Add text-based source files to sources/. Initialization registers usable files as immutable evidence, creates a shallow cited page for each source, and builds an initial relationship map.
- Answer from what already exists. Each question checks the wiki first, then raw sources, and only asks for approval before using web research when that is needed.
- Make useful work reusable. New knowledge is saved with citations and meaningful links; the affected graph is reconciled and validated instead of creating duplicate notes.
Why it matters
The result is not a folder of notes that slowly goes stale. It is a knowledge layer that gets more useful as you add sources and ask better questions—so the next agent starts with context instead of a blank slate.