limestone
limestone
Your notes. Your files. Your terms.
Limestone is a local-first, AI-native notebook. Your notes live as ordinary files you own — readable by you, by any tool, and by whatever AI you choose to bring. No lock-in, no black box, no one reading over your shoulder.
Your files are stored in open file formats — ordinary UTF-8 Markdown, plain folders, standard CSV and PDF. Nothing lives in a proprietary database you can't open without us. Copy your vault to another machine, another tool, or nowhere at all: the notes are just files, and they're yours to take anywhere.
Your files stay where you put them — on your device, in your folders. We never read them. Snapshots are local by default and carry no telemetry; nothing is uploaded, mirrored, or phoned home unless you explicitly connect a destination you control. Your notebook is private because it never has to leave.
Your notes are the source of truth — under your control, not your model provider's. Every AI edit is a proposal you preview exactly, line by line, and approve or reject. An atomic revision check means a stale suggestion can never silently overwrite newer work. The record only changes when you say so.
Your notes are readable by people and by machines at once — plain text a human can edit today, structured enough for any level of AI in your workflow tomorrow. A versioned, review-first agent interface (MCP-compatible) lets tools read and propose changes without ever taking control. Bring more AI, or none. It keeps working.
Limestone is open-source and free for your personal notes — forever. When you're ready to collaborate, shared notes are $2 per seat / month. No per-feature paywall, no locking your own data behind a subscription: the app is open, and the price is for working together, not for getting your notes back.
Own your notes in formats that will still open in ten years. Try Limestone.