What is Obsidian Second Brain used for?

Obsidian Second Brain gives Claude Code and other CLI agents persistent memory stored as plain Markdown notes in your Obsidian vault. It is a good fit for giving Claude Code long-term project memory and maintaining a self-updating personal knowledge base.

Is Obsidian Second Brain open source?

Yes. Obsidian Second Brain is open source under the MIT licence. Its source code is on GitHub at eugeniughelbur/obsidian-second-brain and is written mainly in Python.

Is Obsidian Second Brain free?

Yes. Obsidian Second Brain is open source, so the software itself is free to use.

What are some alternatives to Obsidian Second Brain?

Similar open-source tools in the AI Tools category include LLM Wiki, pi-llm-wiki and oh-my-claudecode. SaaS products in the same category include Agent One, Aldena and AtomicBot.ai.

Is Obsidian Second Brain actively maintained?

Yes. The most recent commit to Obsidian Second Brain was on 1 October 2026, and the latest release is v0.17.0, published on 26 September 2026. The project has 4.7k stars on GitHub.

Obsidian Second Brain: open-source AI tools

About Obsidian Second Brain

Obsidian Second Brain is a toolkit that turns an Obsidian vault into long-term memory for command-line AI agents. The idea is that Claude Code, Codex and other agents share the same Markdown notes, so you stop re-explaining your projects, decisions and people each session, and the vault survives whichever agent you switch to.

It is described as an evolution of Andrej Karpathy's LLM Wiki pattern: every new source updates existing pages instead of only adding new ones, and contradictions are reconciled automatically. Knowledge follows a model called Open Knowledge Metabolism, where every stored fact is classed as timeless, dated or a pointer to elsewhere, which stops stale facts from piling up. The project advertises 45 commands, including hybrid semantic search, self-rewriting notes, web research without API keys and scheduled agents that maintain the vault.

It is written in Python, licensed under MIT and runs locally against your own files, with no hosted service involved. It suits developers, founders and other heavy agent users who already keep their notes in Obsidian.

Key features

Persistent memory for CLI coding agents
Plain Markdown notes in an Obsidian vault
Hybrid semantic search over the vault
Self-rewriting notes that reconcile contradictions
Web research without API keys
Scheduled agents that maintain the vault

Good fit for

→Giving Claude Code long-term project memory
→Maintaining a self-updating personal knowledge base

Built with: Python
Tags: obsidian; ai-memory; claude-code; knowledge-management; markdown; second-brain; ai-agents; pkm

Obsidian Second Brain: questions and answers

What is Obsidian Second Brain used for?: Obsidian Second Brain gives Claude Code and other CLI agents persistent memory stored as plain Markdown notes in your Obsidian vault. It is a good fit for giving Claude Code long-term project memory and maintaining a self-updating personal knowledge base.
Is Obsidian Second Brain open source?: Yes. Obsidian Second Brain is open source under the MIT licence. Its source code is on GitHub at eugeniughelbur/obsidian-second-brain and is written mainly in Python.
Is Obsidian Second Brain free?: Yes. Obsidian Second Brain is open source, so the software itself is free to use.
What are some alternatives to Obsidian Second Brain?: Similar open-source tools in the AI Tools category include LLM Wiki, pi-llm-wiki and oh-my-claudecode. SaaS products in the same category include Agent One, Aldena and AtomicBot.ai.
Is Obsidian Second Brain actively maintained?: Yes. The most recent commit to Obsidian Second Brain was on 1 October 2026, and the latest release is v0.17.0, published on 26 September 2026. The project has 4.7k stars on GitHub.