brain-mcp server

brain-mcp

Your Obsidian vault, as memory for every AI you use.

An open-source Model Context Protocol server that serves your notes, from your own machine, to Claude and any MCP client.

Website · Quick start · How it works · Contribute · Research questions

Why brain-mcp

Every new chat starts from zero. You explain who you are, what you are building and how you like to work, and tomorrow, in another app, you explain it again.

brain-mcp keeps that context in the Markdown notes you already own. Connect any MCP client and it learns who you are, how you work, what your projects are and what you touched this week. It can search, follow links and write back to the vault as you talk.

• Your files, your machine. Notes stay plain Markdown in a folder you control. Nothing is uploaded to a third party.
• One memory, every client. Claude Code, Claude Desktop, claude.ai, Cursor, Hermes Agent, your phone and anything else that speaks MCP read the same vault.
• Hybrid retrieval, fully local. Keyword search plus meaning search with a small embedding model, then a reranker, all on your CPU. It can also answer "the vault does not record this" instead of guessing.
• Measured. Every ranking change is scored by two bundled evals, keyword and hybrid side by side.
• Private by default. OAuth 2.1 with PKCE for remote access, read, write and private scopes, secret redaction and an audit log of every call.
• Writes back. brainremember and braincapture turn what a model learns into notes you can read and edit.
• Small and readable. About 3,800 lines of strict TypeScript. Easy to study, easy to extend.

How it works

flowchart LR
    V["Obsidian vault<br/>plain Markdown"]

Shortened. The full README is on GitHub.