Free
For exploring, contributing, and building your first Cairns.
US$0forever
- ✓Read public Cairns and contribute, without limits
- ✓Own 3 private and 3 team collections
- ✓50 AI asks a day, MCP included
A shared memory map for people and AI.
Every AI you use,
up to speed.
Every memory you pick keeps its receipt: where it came from, who said it, what was decided. Claude, ChatGPT, and Cursor read them over MCP. You decide what stays.
why cairn
Most memory can't say where it came from.
Chat history scrolls away. Notes stay in one head. An agent that remembers can't show you which sentence it remembered, so you can't check it, correct it, or hand it to the next person.
For yourself
Save a decision with its source. Recall it next week, in the next project, from any agent you use.
For your agent
It reads over MCP and cites the card, not a hunch. When it's wrong, you see why and delete it.
For your team or community
The same question gets answered once, with the answerer's name on it. Newcomers walk the map instead of asking again.
how it works
A loop, not an upload.
Knowledge shows up in the middle of the work. Cairn keeps the cost of saving it to one review.
01
Capture
From a session, a meeting, or a note you write yourself. Every candidate keeps its source.
02
Review
You approve, edit, or reject. Nothing is published on its own.
03
Map
Cards are filed into islands and clusters, so the map stays readable as it grows.
04
Reach
People read it here. Agents read it over MCP. The next session starts a step ahead.
see it
Ask a question. Get an answer with sources.
One question lights up the cards that answer it, and the people who wrote them.
Disagreement stays visible. It is part of the answer.
walk in
A world, not a search box.
The map is hand-drawn. Each island is one region of a group's thinking. You walk to the one you need.
Distance gives shape to what is known.
Moss Care
Memory grows stale. Moss helps you notice.
Moss checks for knowledge that may be stale or missing, explains what it noticed, and leaves revision proposals you can review.
Moss only proposes. You decide what enters the Cairn; authored knowledge is never rewritten behind your back.
- 01
Find potentially stale knowledge
Compare older memories with newer evidence and surface what is worth checking again.
- 02
Make knowledge gaps explicit
Turn recurring questions without reliable answers into clear proposals for review.
- 03
Keep judgment human
Approve, edit, or reject. Running Care never publishes or changes a card by itself.
for developers
The same memory, reached from where you work.
One config line connects Claude Code, Cursor, Codex CLI, or any MCP client. Reading is free; nothing is written without your review.
MCP · read
ask_cairnPull the last visitor's note.
Your agent asks. Cairn returns the field note from the last person who hit this wall, handle attached.
skill · write
/cairn-reflectKeep the note before it fades.
At session end, the skill drafts a candidate. You say yes. The card waits in pending for review.
works with your agents · via MCP
Claude Code
Cursor
Windsurf
Codex CLI
Gemini CLI
Antigravity
GitHub Copilot
Aider
Prefer to keep it on your machine? cairn-memory is open source, with the same receipts, stored locally. View on GitHub →
Simple plans, one shared principle
Knowledge shared with the community stays free.
Every community, its own cairn.
The cairn is open to walk. Writing is still gated; leave your email and we'll let people in by hand.