The open-source notebook your AI tools write to.

Open your notebook.

Your notes by subject, with everything you saved beside them.

• Notes by subject

  Markdown with code, and the PDFs and links you're reading, filed together.
• Ask your notes

  A model in your browser or on your own machine answers from what you wrote.
• Your agents write here too

  Claude Code, Codex and Cursor save and search your notes over MCP, and you sign off on what they add.