# Cairntir

> Cairntir is free, open-source memory for AI coding agents. It runs on the user's machine as an MCP server, keeps a project's decisions, facts, open work and outcomes word for word, and gives every connected agent the same history through handoffs and recall.

- License: MIT, free to use.
- Requirements: Python 3.11 or newer.
- Install: `pip install --upgrade cairntir`, then `cairntir setup`, then restart the agent. `cairntir doctor` checks the install.
- Works with: Claude Code, Cline, Codex CLI, Copilot CLI, Cursor, Gemini CLI, OpenCode and Qwen Code, connected automatically by setup. Any other MCP client can connect with the `cairntir-mcp` command.
- How memory is organised: a wing is a project, a room is a topic inside it, and a drawer is one memory, stored word for word.
- Handoffs deliver complete memories, never fragments. Anything too long for a handoff is listed so it can be opened in full.
- What was expected and what actually happened are kept side by side; neither overwrites the other.
- Privacy: memory and search stay on the user's machine. The first run downloads a small local search model; the only other network calls are optional update checks and any AI provider the user chooses to connect. No telemetry.
- Maintainer: Patrick McGuire (McGuire Digital).

## Docs

- [README](https://github.com/pnmcguire480/cairntir/blob/main/README.md): overview, install and supported tools
- [Getting started](https://github.com/pnmcguire480/cairntir/blob/main/docs/how-to-use.md): first session, remembering and handoff
- [Concepts and privacy](https://github.com/pnmcguire480/cairntir/blob/main/docs/concept.md): wings, rooms, drawers and what stays on your machine
- [Roadmap](https://github.com/pnmcguire480/cairntir/blob/main/docs/roadmap.md): what's available now and what's next

## Project

- [Source on GitHub](https://github.com/pnmcguire480/cairntir): code, issues and releases
- [Package on PyPI](https://pypi.org/project/cairntir/): published versions
- [Changelog](https://github.com/pnmcguire480/cairntir/blob/main/CHANGELOG.md): release history
- [Security policy](https://github.com/pnmcguire480/cairntir/blob/main/SECURITY.md): how to report a vulnerability

## Optional

- [Website](https://cairntir.com/): the overview page this file accompanies