I Rewrote a OneNote MCP Server in TypeScript — Here's What I Learned About Microsoft Graph Auth

A developer rewrote a OneNote MCP server in TypeScript after encountering 401 errors with an existing version. The Model Context Protocol (MCP) allows AI assistants like Claude Desktop, Cursor, and Claude Code to call external tools via JSON-RPC. By exposing tools such as listNotebooks and createPage, the server enables AI to read notes. Communication occurs over stdio, utilizing JSON-RPC on stdout and diagnostics on stderr to facilitate seamless integration between the AI and OneNote.