# PM Brain OS: The Second Brain for Product Managers, Made of Markdown

DevFeed: [PM Brain OS: The Second Brain for Product Managers, Made of Markdown](<https://devfeed.tech/articles/pm-brain-os-the-second-brain-for-product-managers-made-of-markdown-39181.md>)

Original publisher: [Read original article](<https://www.productcompass.pm/p/pm-brain-os>)

Author: Paweł Huryn

Published: 2026-05-20T13:09:25Z

Content type: tutorial

Language: en

Sources: [The Product Compass](<https://devfeed.tech/sources/the-product-compass.md>)

Topics: [Claude Code](<https://devfeed.tech/topics/claude-code.md>), [MDX](<https://devfeed.tech/topics/mdx.md>), [Open Source](<https://devfeed.tech/topics/open-source.md>)

Tags: [audit-trail](<https://devfeed.tech/tags/audit-trail.md>), [claude](<https://devfeed.tech/tags/claude.md>), [claude-code](<https://devfeed.tech/tags/claude-code.md>), [dogfooding](<https://devfeed.tech/tags/dogfooding.md>), [markdown](<https://devfeed.tech/tags/markdown.md>), [open-source](<https://devfeed.tech/tags/open-source.md>), [provenance](<https://devfeed.tech/tags/provenance.md>), [rag](<https://devfeed.tech/tags/rag.md>), [repo](<https://devfeed.tech/tags/repo.md>)

## AI overview

The article presents PM Brain, an open-source second-brain system for product managers built from Markdown files in a Git repository. Claude reads and updates the files according to a CLAUDE.md operating manual, while weekly sweeps promote recurring, decision-relevant, or strategy-relevant information into a durable layer. The system intentionally avoids vector databases, embeddings, cloud storage, and automatic tagging, and includes installation guidance, commands, architecture details, provenance, and evaluation results.

## Source excerpt

A folder of files on your laptop. Claude reads them before answering, writes to them after, sweeps them every Friday. Open source. 17 synthetic PM scenarios, 404 of 406 checks pass (~=99.5%).