# Octobrain

Keeps decisions and notes across sessions, then pulls them back by meaning instead of keywords. Useful when your assistant meets your project for the first time every morning.

- MCP server · `type=mcp` · Claude Code, Codex, Cursor, GitHub Copilot, Windsurf (Devin Desktop), Cline, Zed, Gemini CLI · ★ 15
- Author: Muvon
- License: Apache-2.0 · policy=link-only · description only; the file stays with the author
- Source: https://github.com/Muvon/octobrain
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/mcp/octobrain

## What it does

Octobrain closes the loop where each chat starts blank. You write down an insight with a title, a type and tags, and later ask for it in plain language — the search matches on meaning. Similar entries link themselves the way a Zettelkasten does, and you can walk those links as a graph.

The package ships a Rust CLI plus an MCP server on the same store. `octobrain memory memorize` writes, `octobrain memory remember` searches, `octobrain memory relate` connects two entries, `octobrain memory graph` shows the neighbourhood at a chosen depth. A `knowledge` branch indexes URLs and local `.md`, `.pdf`, `.docx`, `.txt`, `.html` files, with `knowledge read` returning the full text. Housekeeping lives in `memory maintenance` (compacts tables, rebuilds indices) and `memory cleanup`.

Default builds embed locally with FastEmbed and HuggingFace, so no API key is involved. Building with `--no-default-features` switches to Voyage, OpenAI, Google or Jina, and search stays dead until the matching variable such as `OPENAI_API_KEY` is exported. Compiling from source wants Rust 1.95 or newer.

## Requirements
- Needs: Node.js (commands run via npx)

## Install

### Claude Code (native platform)

**Platform CLI**
```bash
claude mcp add octobrain -- npx -y @muvon/octobrain
```

### Codex

**Platform CLI**
```bash
codex mcp add octobrain -- npx -y @muvon/octobrain
```

### Cursor

**Config file**
File `.cursor/mcp.json`:
```json
{
    "mcpServers": {
        "octobrain": {
            "command": "npx",
            "args": [
                "-y",
                "@muvon/octobrain"
            ]
        }
    }
}
```

### GitHub Copilot

**Config file**
File `.vscode/mcp.json`:
```json
{
    "servers": {
        "octobrain": {
            "type": "stdio",
            "command": "npx",
            "args": [
                "-y",
                "@muvon/octobrain"
            ]
        }
    }
}
```

### Gemini CLI

**Platform CLI**
```bash
gemini mcp add octobrain npx -y @muvon/octobrain
```

## When to use it
- restore project context at the start of a fresh session
- retrieve a past fix by meaning rather than an exact phrase
- connect notes about module dependencies into a graph
- index a library's docs and query them later
- prune stale entries before starting new work

## Example prompts
- Save this as an architecture decision: REST for CRUD, GraphQL for complex reads. Tag it api
- Search my memory for how we handled background jobs in tokio
- Index `./docs/architecture.md` and pull out the part about auth

## Similar
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