TooL Void
New Desktop App

One Brain

A private, local-first memory for your AI tools.

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FreeOpen source (MIT)Linux · Windows · macOSNo cloud server

Features

Memory, search, and connections stay in one desktop app.

Encrypted local database

Memories live in an encrypted SQLite database on your computer.

Master-password vault

Use auto-lock, escalating lockout after wrong passwords, and an encrypted recovery file.

3D memory graph

Browse memories from Claude, ChatGPT, Gemini, Codex, Groq, DeepSeek, Perplexity, and Built-In, with suggested links between related memories.

Smart search

SQLite full-text search and multilingual MiniLM embeddings let “cooking” find a recipe.

Built-in chat

Use your own API keys, choose a provider and model, and ask your saved memories.

Connections dashboard

See which AI clients and browser chats are connected.

MCP server

Connect MCP clients to your memories.

Local memory proxy

Use an authenticated OpenAI-compatible proxy on your machine.

Quick Context

Grab relevant context quickly; the global shortcut does not work on Wayland.

Import

Bring existing memories into One Brain.

Private memories and review

See context before it is sent to an AI.

Pending memories

Review items before they are saved.

Insights

Activity, Evaluation, and Status views show usage, retrieval quality, and health.

Clear error codes

OB-... errors include built-in Retry actions, with a graphics fallback for machines where the GPU crashes.

Offline use

Work fully offline after the first-time roughly 130 MB embedding model download.

How It Works

From your first vault to reusable context.

  1. 1
    Download for your system.

    Choose the Linux, Windows, or macOS download below.

  2. 2
    Install or run it.

    Follow the steps in Install for your operating system.

  3. 3
    Create your vault.

    Set a master password and save the recovery file somewhere safe.

  4. 4
    Add or import memories.

    Bring your existing memories into One Brain.

  5. 5
    Run your first search.

    Internet is needed once for the roughly 130 MB local model. If it fails, connect and press Retry for OB-EMBED-001; it also recovers after reconnecting.

  6. 6
    Connect an AI.

    Open Settings → Connections to set up an MCP client, local proxy, or browser extension.

  7. 7
    Search and chat.

    Find memories, chat with them, and review context before sending.

Download One Brain

Choose a build for your computer.

Windows x64

Latest release

Installer · Approx. 164 MB

Experimental: built and smoke-tested in CI, not yet tested on real machines.

Download for Windows

macOS Apple Silicon

Latest release

DMG · Approx. 200 MB

Experimental: built and smoke-tested in CI, not yet tested on real machines. Intel Macs are not supported.

Download for macOS
All releases

Install One Brain

Choose your operating system for installation steps.

Linux installation

  1. Download the AppImage.
  2. Open a terminal in the download folder.
  3. Make it executable. The filename may include a version.
    Terminal
    chmod +x One-Brain-linux-x64.AppImage
  4. On Ubuntu 22.04 and newer install FUSE:
    Terminal
    sudo apt install libfuse2t64
    On older Ubuntu or Debian:
    Terminal
    sudo apt install libfuse2
  5. Run the AppImage:
    Terminal
    ./One-Brain-linux-x64.AppImage
  6. Optional: in your file manager choose Properties → Allow executing as program, then double-click.
  7. Data is stored at ~/.config/one-brain. To uninstall, delete the AppImage; also delete that folder if you want to remove your data.
Wayland: One Brain relaunches under XWayland to avoid a GPU crash on some Intel graphics. For terminal logs, run:
Terminal
ONE_BRAIN_OZONE=auto ./One-Brain-linux-x64.AppImage

If the window is blank or graphics crash, choose Settings → Graphics mode → Software.

Install the browser extension

Pair browser chats with the One Brain desktop app.

Chrome / Brave / Edge

Download extension (.zip)
  1. Download and unzip the folder.
  2. Open chrome://extensions (Chrome; Edge can use edge://extensions).
  3. Turn on Developer mode.
  4. Click “Load unpacked” and select the unzipped folder.
  5. Optional: pin the extension from the puzzle icon.
The extension stays installed after restart. On startup, the browser may show a “developer mode extensions” popup. Click Cancel or X, not “Disable”. If it gets disabled, open your browser’s extensions page and turn it back on. Do not move or delete the unzipped folder; the browser loads the extension from it.

Firefox

Install for Firefox

This is a permanent install and survives restarts.

Help

Answers for setup, recovery, and common issues.

App will not start on Linux
Install FUSE (libfuse2) and make the AppImage executable with chmod +x.
Window is blank or graphics crash
Open Settings → Graphics mode → Software. On Wayland, run with ONE_BRAIN_OZONE=auto to see terminal logs.
Semantic search needs attention / OB-EMBED-001
The first model download needs internet. Connect and press Retry; it also recovers after reconnecting.
I forgot my master password
Use the encrypted recovery file saved when you created the vault. Without it, the data cannot be recovered; this is by design.
Where is my data?
On Linux, data is in ~/.config/one-brain and is encrypted.
Windows or macOS shows a security warning
The installers are unsigned. On Windows choose More info → Run anyway; on macOS right-click the app and choose Open.
Does One Brain send my data anywhere?
There is no One Brain cloud server. If you send context to an online AI provider, that provider receives it.
What do the OB- error codes mean?
Report a bug or ask a question

Keep your AI context close.

Download One Brain or explore the project on GitHub.

DownloadStar on GitHub

Got feedback or a suggestion?

Tell me what you'd want a shared AI memory to do. Bugs, ideas and recommendations are all welcome.

0voidtool0@gmail.com

Email me

A private, local-first memory for your AI tools

One Brain is a desktop app with an encrypted SQLite database, a master-password vault, smart search, built-in chat, an MCP server, a local memory proxy, Quick Context, import, pending memories, and Insights. Search combines SQLite full-text search with multilingual MiniLM semantic embeddings. The first search needs internet once to download the approximately 130 MB local model; after that, the app works fully offline.

Review context before sending it to an AI. One Brain has no cloud server, though an online AI provider receives context you send to it. The browser extension is coming soon and will pair with the desktop app.

Example: Search for a saved memory, then review its context before sending it to an online AI provider.

How to use it

  1. Download the build for your system.
  2. Install or run One Brain.
  3. Create a vault with a master password and save the recovery file somewhere safe.
  4. Add or import memories.
  5. Search; the first search needs internet once to download the approximately 130 MB local model.
  6. Open Settings → Connections to connect an MCP client, local proxy, or browser extension.
  7. Search, chat with your memories, and review context before sending.

Frequently asked questions

Where are One Brain memories stored?

They are kept in an encrypted database on your computer; One Brain has no cloud server.

Does semantic search work offline?

The first search needs internet once to download the approximately 130 MB local embedding model. After that, One Brain works fully offline.

Is the browser extension available?

It is coming soon. Install the desktop app first; the extension will pair with it.

Does an online AI provider receive sent context?

Yes. If you send context to an online AI provider, that provider receives it. Review context before sending.

Which computers are supported?

Downloads are provided for Linux x64, Windows x64, and macOS Apple Silicon. Intel Macs are not supported.