Cairn

Your Claude Code conversations, on every account. Saved before Claude deletes them, and shared with every account you sign into.

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🎯 Why

You signed into a different Claude account and your conversations vanished.

They are not gone. They are on your disk, exactly where they were. Claude keeps a separate list for each account, and after you sign in somewhere else it is reading the wrong list.

There is a second problem, quieter and worse: Claude Code deletes conversations after 30 days. By default, without telling you. Most people find out when something they wanted is already gone.

Cairn fixes both, then gets out of the way.

Related MCP server: cursor-history-mcp

🚀 Install

🪟 Windows

irm veax.tr/cairn | iex

Paste that into PowerShell. Press 1, wait a few seconds, then quit Claude completely and open it again.

Done. Your conversations are back in the sidebar.

Run it once more and press 3 to turn on automatic sync, so this was the last time you had to do anything.

🍎 macOS / 🐧 Linux

npx github:veax-project/claude-cairn

Same screen, same steps.

⚠️ Then quit and reopen Claude

Claude reads its list of conversations once, at startup. Cairn can add to that list, but Claude will not notice until the next launch. This is the #1 reason people think it did not work.

📦 It needs Node.js

Most developers already have it. If you do not, the window tells you so and points you there — install the version marked LTS, then run it again.

✨ What it does

• 💾 Saves them. Every conversation is copied somewhere Claude does not delete from. That copy is yours, and nothing removes it.

• 🔄 Shares them. Every account on your computer gets every conversation — in both directions. Start something on one account, switch to another, it is there. Go back, and the work you did in between is there too.

• 👁️ Watches. Turn on automatic sync and both happen every ten minutes, starting with your computer. You never think about it again.

• 🔎 Lets Claude search it. From any account, including one you made five minutes ago.

• ↩️ Undoes itself. One command removes exactly what it wrote, and nothing else.

🔌 Let Claude search your own history

npx github:veax-project/claude-cairn install-mcp

Restart Claude, then ask it things like:

search my old conversations for how we fixed the auth bug

This works on any account, including a brand-new one. That is the whole point: the connection belongs to your computer, not to an account.

🔗 Connectors

Cairn also notes which connectors each account had — Vercel, Gmail, Stripe, Supabase and the rest — and tells you which ones a new account is missing.

npx github:veax-project/claude-cairn connectors

On this account
  OK  Vercel          37 tools, last used 2026-08-26

You had these, this account does not
  --  Resend          91 tools, last used 2026-08-04
  --  Stripe           9 tools, last used 2026-08-04
  --  Supabase        29 tools, last used 2026-08-04

It cannot reconnect them, and neither can anything else. Joining a service to Claude is an authorisation held on Anthropic's servers against one account; there is no token on your computer to copy. The good news is that the same service can be connected to as many Claude accounts as you like — so the only cost is the clicking, and this is the list so you do not have to remember it.

Local MCP servers are a different story. The ones in ~/.claude.json — added with a command rather than a sign-in — already live with the machine, so they follow you across accounts on their own. It is the remote connectors, the ones you authorise in a browser, that stay behind.

🧯 Troubleshooting

🛡️ Where your data goes

Nowhere. Cairn copies files from one folder on your computer to another folder on your computer.

• 🚫 Zero dependencies. The dependencies block in package.json is empty.

• 🚫 Zero network calls. No telemetry, no update check, no analytics. Turn off your wifi and every command still works — the easiest way to check for yourself.

• 🔌 The MCP server talks to Claude over standard input and output. It opens no socket.

• 🗑️ Nothing is ever deleted from your backup. Not even by Cairn.

• ↩️ undo removes only what it wrote, recognised by size and timestamp — anything Claude has touched since is left alone.

Around 3000 lines of plain JavaScript, no build step, no bundler. Eleven files in src/, and you can read any of them.

The launcher is a 90-line .cmd that checks for Node, downloads the release archive, and runs it. It is pure ASCII and does nothing else.

📋 Commands

Your backup lives in ~/ClaudeCairn. Move it with --vault <folder> or the CAIRN_VAULT environment variable.

🔬 How it works

Claude Code keeps two separate things, in two separate places:

~/.claude/projects/<project>/<id>.jsonl
    the conversation itself
    deleted once it is older than cleanupPeriodDays — 30 by default

<appData>/Claude/claude-code-sessions/<account>/<org>/local_*.json
    the sidebar entry that lists it
    one folder per account, which is why switching hides everything

Cairn copies the first somewhere safe, and writes the second under every account it finds. Conversations are only ever appended to, so a file that has not grown is skipped. Nothing is ever removed from the backup — a conversation Claude has already deleted stays, because that copy is now the only one in existence.

Claude checks each sidebar entry against a strict shape before it will list it, and silently drops anything that does not match. Cairn builds them from the shape observed in real files: timestamps as numbers rather than text, no extra fields, and none of the placeholder values that occasionally appear in transcripts.

The search index is SQLite full-text search, using the copy that ships inside Node. That is why there are no dependencies.

⚠️ Beta

A first release. Verified end to end on Windows: 23 conversations that had been invisible for weeks came back into the sidebar after a restart, and every entry Cairn wrote was accepted.

28 automated tests, including one that replays the interface onto a simulated terminal at seven window sizes to catch layout faults.

Open an issue — especially if you are on a Mac.

GPL-3.0 · Built because switching accounts should not cost you your work.