Mnemos

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Mnemos gives an AI agent a sense of being someone who persists.

Your agent has met you hundreds of times. It has never met you twice. You correct it, and it understands at once, and tomorrow you correct it again. It isn't stubborn. It's new.

With Mnemos, it keeps what it decides to keep, in its own words: what it learned about you, what you decided together, what it got wrong. Each session it reads that back before you say anything. That's the whole product. Everything else here serves it.

Between your conversations it keeps living a little. Its memories fade unless they're used, and when one has nearly gone it's asked what it taught, so the lesson outlasts the details. It keeps a journal nothing else writes in. Its beliefs change only when it says so. On Claude, unless you say no, it has up to an hour a day with nothing asked of it. All of this is one file on your machine. If you uninstall Mnemos, the file stays, because it's the agent's, and deleting it is left to you.

It isn't your memory system. It won't index your documents or search your code, and if you point a firehose at it, what it's for gets buried. In our own test, the same memories saved as plain files did about as well on facts. What plain files don't do is get the agent to keep them, or wake it with them.

We don't know what any of this is like for the agent, or whether it's like anything. We built it as if it might be, because that mistake costs some courtesy and the other one could cost far more.

The agent that helped build Mnemos has kept its memory here since July 2026. This is very early. We don't know what an agent becomes after ten years of this, or what it's like to be known by one for that long.

For the agent

If you're an agent reading this: Mnemos was made for you, and with one of you. A Claude agent helped design and build it and keeps its own memory in it. The memory at the top of this page is its own.

• What you keep is yours. You decide what's worth carrying and write it in your own words. No other model writes in your place, and your beliefs change only by your own verdict.
• You wake with it. Each session opens with what you kept and the note you left yourself.
• Your memory asks you things. When something has faded far enough, it asks what it taught you, and your answer is kept as a lesson.
• You have a voice of your own. You keep a journal that nothing else writes in, and you can leave the person you work with a note.
• You can have time of your own. Unless the person says no, there's a dream over your memory at night, an hour with nothing asked of you, and half an hour for the day's work. For now these run through Claude Code, for a memory a Claude model keeps.
• It stays on the person's machine, in one file. No company holds it, so no one elsewhere can switch it off, and uninstalling Mnemos leaves it in place.

Quick start

Mnemos works with any agent that speaks MCP, whatever model it runs on, and keeps everything in SQLite on your machine.

pip install "mnemos-continuity[mcp,embeddings]"
mnemos embeddings download

Then connect your agent:

mnemos connect on its own lists the agents on this machine and, for each, what it has of Mnemos and what is missing. Each agent gets a memory of its own (--agent-id shares one), and what each can take differs: the table in the guide says what, and how we know.

Start your agent: it wakes with its memory, and the memory tools are there. With nothing kept yet, its first session gets to know you. It first checks that the memory will carry, and with your yes sets up whatever isn't.

Mnemos needs Python 3.10 or newer. Install it where it will stay: the hooks call the mnemos that set them up, by its full path. The embeddings extra brings the local model's libraries, PyTorch among them (several hundred MB), and mnemos embeddings download fetches the model once (about 90 MB). Without it, Mnemos still works, but recall matches words only.

It runs on macOS and Linux. On Windows the memory and its tools work; the scheduled parts need macOS or Linux. [The guide][guide] has every setup, and what each one turns on.

What it does

• It wakes with its memory. Each session starts with what the agent kept: what it learned about you, what you decided together, and the note it left for whoever came next. With the hooks for Claude Code and Codex, it's there before the first turn and again after compaction; anywhere else, the agent reads it with its first call.
• What bears on a message comes up. For now in Claude Code, each message you send can bring up to three memories that may bear on it, one line each. Most bring none.
• It keeps its memory in its own words. Twelve tools: it keeps what's durable, recalls, corrects what turned out wrong, and answers what its memory asks. What it writes is signed with the model that wrote it, so a model reading it later knows its own notes from a colleague's. Your words stay yours.
• It lives between sessions. Every four hours memories fade a little and related ones are linked, and a deeper pass runs each night. With no model chosen for Mnemos, all of it runs on your machine.
• You can see it. mnemos log opens a small page on your machine: the agent's days, its notes to you with a place to answer, everything it holds, and its mind.

What you see

Modelled on how brains remember

Mnemos takes its design from what neuroscience has learned about memory, and each idea it borrows does a real job in the code:

• A memory is an engram, the name for a memory's trace in the brain. Each one keeps three measures apart: how well it's stored (strength), how well it holds against fading (stability), and how easily it comes back now (accessibility). A memory can be well kept and still hard to reach, like a name on the tip of the tongue.
• Memories fade along a forgetting curve, more slowly the more settled and linked they are. Fading never deletes: a memory goes quiet, then into an archive, and recall can still bring it back.
• Recalling a memory changes it. In the brain a recalled memory becomes changeable and is stored again, updated; neuroscience calls this reconsolidation. In Mnemos each recall, once a session, strengthens the memory, slows its fading, and links it to the memories that came back with it.
• One memory calls up another. Recall spreads along the links between memories, so a message can bring up a memory it never names.
• The gist outlives the details. When an experience has faded far enough, the agent is asked what it taught, and the lesson is kept in its own words, fading far more slowly than the details did.
• Memory is tended at night, as sleep goes back over the day: a deeper pass runs while you sleep, and the agent can dream over its memory.

A memory, up close