Octobrain — Claude Code MCP server: memory that lasts
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.
claude mcp add octobrain -- npx -y @muvon/octobrainWhat Octobrain 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.
What it helps with
- 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 for the agent
- 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.mdand pull out the part about auth
How to install Octobrain
Platform CLI
claude mcp add octobrain -- npx -y @muvon/octobrainPlatform CLI
codex mcp add octobrain -- npx -y @muvon/octobrainConfig file
{
"mcpServers": {
"octobrain": {
"command": "npx",
"args": [
"-y",
"@muvon/octobrain"
]
}
}
}Config file
{
"servers": {
"octobrain": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@muvon/octobrain"
]
}
}
}Platform CLI
gemini mcp add octobrain npx -y @muvon/octobrainStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Octobrain
How do I install Octobrain in Claude Code?
Run claude mcp add octobrain -- npx -y @muvon/octobrain. The server is then registered and starts with your session.
What does Octobrain do?
It stores typed, tagged entries, finds them through semantic search and links related ones into a graph. It also indexes local files and web pages so you can search inside them.
Does it need an API key?
A regular build does not — embeddings run locally via FastEmbed and HuggingFace. Keys come into play only when you compile against Voyage, OpenAI, Google or Jina.
