Explore
The whole site, on one page.
Every page, grouped by use, with one sentence to tell whether it is the one you are looking for. And the journal, newest first.
Features
The 73 features of the app, to search or filter by family.
Who it is for
One page per use, written for the person looking for it.
- Students: study a course
The lecturer's PDF, photos of the projector and your Word notes in one memory.
- Teachers: find your courses again
Ten years of courses, exams and papers, found by topic rather than by year.
- Chat with your documents
A folder, a question, the answer cites the file. Offline if you want.
- A local second brain
Notes, documents, web pages and conversations in vaults, on your computer.
- Import from AFFiNE
Get your AFFiNE documents out as Markdown, images included, in one command.
- Obsidian notes
Stay on Obsidian. Your vault becomes a memory you can ask, no plugin.
- Logseq notes
Stay on Logseq. Your graph becomes a memory you can ask, locally.
- Markdown notes
A folder of .md files, whatever the editor, read where it is.
The product
What it is, how it works, what it costs.
- Manifesto
Mnemosyne OS builds the relationship and leaves the intelligence to the model. Why do we call it an OS?
- How it works
The local architecture, the recall mechanisms, the Neural Map.
- All features
The full list, by family, with a search.
- No account, local-first
Which data leaves your machine, to whom, and how to check without trusting us.
- Choosing your memory
A score you can recompute, how it treats your machine, how it searches: what to check before choosing.
- Download
Windows, macOS, Linux. The complete OS, free, no account.
- License
Free for yourself. 70 $ once for the rest, for life.
- Roadmap
What has shipped, what is next.
- The team
An independent lab, and some friends.
Ecosystem
What plugs into it, and what gets built on it.
- MnemoHub
The app store of Mnemosyne OS.
- The catalogue
Every cartridge, most-used first, plus the ones in beta.
- Connect your notes
Obsidian, Logseq, Notion or a Markdown folder: where your notes come from.
- Notion
Keep Notion for building, export your pages, and take them local.
- Your coding agents, across your machines
Agents running in herdr become cards on your board, and your paired computers share the work.
- MnemoHermes: your assistant, named by you
Call your assistant by its name in the app, or write to it on Telegram. Hermes Agent does the work under the hood.
- Vertex AI
Your own Vertex AI key, the memory stays with you.
- The memory dashboard
The Neural Map: your memory as a graph you navigate.
- The Engramm
What an engram is, and the license that carries the name.
Developers
Build on memory: SDK, MCP, cartridges.
- Develop on Mnemosyne OS
Where to start: SDK, MCP, cartridges.
- Build a cartridge
The process, vibe-coded or by hand.
- Commission a cartridge
You have the idea, we build the cartridge.
- npm packages
The dev layer is on npm, MIT.
- The MCP tools
What the MCP server hands your agent, tool by tool.
- GitHub ↗
The public repository: open core, SDK and CLI in the clear.
Resources & legal
To read further, and what the law says.
- Explore the site
Every page on one page, with one sentence each.
- Search
One word, and every page on the site that carries it. The search index lives in your browser.
- Documentation ↗
The guide, engine by engine, step by step.
- Journal
What we measured, what we got wrong, what we shipped.
- Benchmark
77.1% on unseen LongMemEval-M questions, and what it does not claim.
- Lexicon
The words of AI memory, defined.
- Contact
Let's talk.
- Legal notice
Who publishes this site.
- Terms
The terms of sale, fifteen articles.
- Privacy
What this site and the app know about you. It is close to nothing.
The journal
What we measured, what we got wrong, what we shipped.
- AI memory compared: mem0, Zep, Letta, Cognee, Supermemory, us September 13, 2026
Where each published AI memory score comes from: the benchmark, its variant, how many questions, which model graded it. Two of the highest do not say.
- Your memory re-reads itself while you are away September 12, 2026
No single note holds what you spent on the bike this year. So while the machine is idle, your memory re-reads itself and writes the total beside your own notes.
- A multiplier cannot rescue a zero August 18, 2026
Dense embeddings cannot hear a rare proper noun, and doubling a zero is still zero. A second, local ranking fixed it, and 48 new questions confirmed the gain.
- Present is not the same as loadable August 10, 2026
A package can be there, at the right version, and still be unreachable to the code that imports it. How v1.3.7 shipped with no local model.
- We gave personality control of memory. It cost 31 points. August 4, 2026
The most seductive feature we built this year made memory recall worse. The 61-question measurement, the ablation, and why personality shipped as a costume.
- The memory my brain kept asking for July 21, 2026
Why I built a local-first memory OS: a prosthesis for a brain that ran too fast for the world.
- 72.9%, and the three questions we miss July 16, 2026
We ran LongMemEval on the full-haystack variant, the one nobody shows. The number, the protocol, the levers we refuted, and the three misses we own.