Cairn hello@cairnapp.app

Save anything. Ask it anything. Every answer cites what you saved.

Notion holds what you typed. Cairn holds what you read, and hands it to the Claude you already pay for.

Ask for early access

macOS on Apple Silicon · runs on your Mac · free and open source

Cairn's Today page: the week as small cairns, things worth another look, your topics and new finds

What sets it apart

Every answer cites you

Answers come only from your library, each claim numbered to its source, and summaries are checked word for word against the original.

It connects what you saved

Cairn notices which saves disagree and which apply to each other, even months apart.

Private stays private

Your library lives on your Mac. Items you mark private are read only by models running on it and never leave.

Memory for your assistant

Claude Desktop, Claude Code, Gemini CLI, Antigravity, Cursor and Codex can search your library over MCP. Not another chat app charging for tokens.

Save, then ask

Ask: an answer with numbered citations
Ask questions of everything you kept. Each claim opens its source at the right page or second.
Discover: one find at a time, with why it was picked
Discover brings new finds, each judged against what you already keep before you see it.

Who it is for

  • People who read and save a lot: developers, researchers, students and writers.
  • Anyone already using Claude, Cursor, Claude Code or Gemini CLI who wants it to know what they have read.
  • Owners of an Apple Silicon Mac who want their reading to stay on it.

Want to try it first?

Cairn is in its last stretch before a public release. Write and you will hear when it is out.

Ask for early access