@mdgate/onenote

Convert Microsoft OneNote files to Markdown in TypeScript.

@mdgate/onenote reads .one, .onetoc2, and .onepkg files directly in JavaScript and converts page text into GitHub-Flavored Markdown, without Python, native addons, WASM, or OneNote.

Works in Node.js, Cloudflare Workers, Edge runtimes, and browsers.

npm install @mdgate/onenote

import { toMarkdown } from '@mdgate/onenote';

const markdown = await toMarkdown(bytes);

bytes is a Uint8Array, so the notebook can come from a file upload, object storage, an HTTP request, a browser file picker, or anywhere else your application gets bytes.

Why @mdgate/onenote

OneNote stores notes in a proprietary revision format. There is no HTML or DOCX sitting inside a typical .one file.

@mdgate/onenote is a OneNote reader written for the same runtime as your application:

• Pure TypeScript
• OneNote → Markdown locally
• No Python runtime
• No native addons
• No WASM runtime
• Zero third-party runtime dependencies
• Works with raw Uint8Array input
• Detects OneNote files from their contents, not only the filename

What it extracts

This converter is best-effort text extraction, not a full OneNote renderer.

It collects:

• page titles when they can be recognized
• readable body lines from OLE streams or packed bytes
• .onepkg ZIP members: when composed with create(), inner .one files are passed back through the same reader

It does not reconstruct OneNote ink, embedded files, or exact page layout.

Node.js

import { readFile } from 'node:fs/promises';
import { toMarkdown } from '@mdgate/onenote';

const bytes = new Uint8Array(await readFile('meeting.one'));
const markdown = await toMarkdown(bytes);

console.log(markdown);

Browser

import { toMarkdown } from '@mdgate/onenote';

const file = input.files![0];
const bytes = new Uint8Array(await file.arrayBuffer());

const markdown = await toMarkdown(bytes);

Cloudflare Workers and Edge runtimes

import { toMarkdown } from '@mdgate/onenote';

export default {
  async fetch(request: Request) {
    const bytes = new Uint8Array(await request.arrayBuffer());
    const markdown = await toMarkdown(bytes);

    return new Response(markdown, {
      headers: {
        'content-type': 'text/markdown; charset=utf-8',
      },
    });
  },
};

Format detection

You do not need to trust the file extension.

@mdgate/onenote recognizes OneNote OLE files and .onepkg ZIP packages from their contents.

const markdown = await toMarkdown(bytes);

A path can still be supplied as a format hint when @mdgate/onenote is used through @mdgate/converters or a reader composed with @mdgate/core, but the path is never used to read a file from disk.

Compose it with other file readers

@mdgate/onenote implements the converter interface from @mdgate/core.

import { create } from '@mdgate/core';
import { onenote } from '@mdgate/onenote';
import { docx } from '@mdgate/docx';

const read = create([
  onenote(),
  docx(),
]);

The application still uses one reading interface while each format remains independently installable.

Need more than OneNote?

If your application needs to read many different file types, use the complete converter set:

npm install @mdgate/converters

import { toMarkdown } from '@mdgate/converters';

const markdown = await toMarkdown(bytes, {
  path: filename,
});

@mdgate/onenote is one of the single-format packages in the open-source mdgate/converters project.

For AI agents, the same converter architecture can be used to extend read_file from text files to real-world document formats.

License

MIT