Mnemosyne OS is a desktop operating system for memory. Not a chatbot that happens to remember: memory is the primitive, and AI is one of several ways to question it.
YOUR MEMORY, ON YOUR DISK
Point it at folders you already have. It watches them and turns documents, notes, PDFs, images, captured web pages and your agents' own transcripts into searchable memory, stored in vaults on your own drive, one per area of life: code, research, journal, work. Each vault carries its own protection level, and two vaults never mix unless you say so. Retrieval is hybrid, semantic plus lexical, and runs on your machine, so search still answers with the cable unplugged.
ANY MODEL, OR NONE
Bring your own key (Anthropic, OpenAI, Google, Mistral), point it at your own server, or run a local model. Embeddings and ranking stay local either way.
A CONTROL ROOM FOR YOUR AGENTS
This is where it stops being a note app. An MCP server ships with it, so Claude Desktop, Claude Code and any MCP client draw on the same memory instead of starting from zero every session. A bridge connects VS Code and Cursor. Connectors read what your coding agents already write to disk, so you can see every session running on your machine, what files each one actually touched, and get warned when two agents are working in the same git tree. Agents publish status cards you pin on the canvas and answer from there. A loopback endpoint can even serve your own inference to a local agent.
AN ECOSYSTEM, NOT A FEATURE LIST
The interface is a spatial canvas rather than a stack of tabs, spread across several desktops. On it live chat, vaults, notes, a neural map of your own memory, a to-do, an agenda, an image studio, a PDF reader, a capture browser, a conversation recorder, and voice in and out. MnemoHub adds third-party cartridges: real apps with their own declared permissions. An SDK lets you build your own.
Free to use, with a one-time $70 licence (perpetual, no subscription) that unlocks local neural voices, heavy local OCR, and premium MnemoHub cartridges. Windows, macOS and Linux.
The MCP server, the SDK and the cartridge SDK are published on npm under the MIT licence.
Comments and Reviews
I am the developer of Mnemosyne OS, so read this as a maker's note.
What I use it for every day: it keeps track of all my projects, it keeps an eye on my codebase, and it makes me more curious, because everything I read, it remembers, so I can ask for it later instead of losing it.