html-to-oft

Create Outlook .oft template files from HTML in Node.js.

html-to-oft generates CFB/OLE structured storage files with MAPI-style message streams, so templates can be created without Outlook, Windows COM automation, or platform-specific runtime dependencies.

Installation

npm install html-to-oft

Requires Node.js 18 or newer.

Usage

import { createOft } from 'html-to-oft';
import { writeFile } from 'node:fs/promises';

const oft = await createOft({
  subject: 'Newsletter',
  html: `
    <table role="presentation" width="600" cellpadding="0" cellspacing="0">
      <tr>
        <td>
          <img src="https://example.com/header.png" width="600" alt="">
        </td>
      </tr>
    </table>
  `,
});

await writeFile('newsletter.oft', oft);

API

createOft(input)

Creates an Outlook template and returns a Buffer.

const oft = await createOft({
  subject: 'Promo',
  html: '<h1>Hello</h1>',
  text: 'Hello',
  to: ['[email protected]'],
  cc: [{ email: '[email protected]', name: 'Manager' }],
});

Input fields:

| Field | Description | | --- | --- | | html | Required HTML body. | | subject | Message subject. | | text | Plain-text body. Generated from HTML when omitted. | | from | Sender metadata. | | recipients | Explicit recipient list. | | to, cc, bcc | Recipient shortcuts. | | attachments | Binary attachments. |

Attachments

const oft = await createOft({
  subject: 'With attachment',
  html: '<p>See attached.</p>',
  attachments: [
    {
      filename: 'document.pdf',
      content: pdfBuffer,
      mimeType: 'application/pdf',
    },
  ],
});

Inline attachments can be referenced with cid and inline.

const oft = await createOft({
  subject: 'Inline image',
  html: '<img src="cid:image001.png@example" width="600" alt="">',
  attachments: [
    {
      filename: 'image001.png',
      content: pngBuffer,
      mimeType: 'image/png',
      cid: 'image001.png@example',
      inline: true,
    },
  ],
});

patchOftTemplate(baseOft, input)

Updates known subject, body, and HTML streams in an existing template.

import { patchOftTemplate } from 'html-to-oft';

const patched = await patchOftTemplate(existingOft, {
  subject: 'Updated subject',
  html: '<h1>Updated</h1>',
  text: 'Updated',
});

inspectOft(buffer)

Reads a template and returns a structural summary.

import { inspectOft } from 'html-to-oft';

const info = inspectOft(oft);

console.log(info.hasHtml);
console.log(info.attachmentCount);

HTML Helpers

import { htmlToText, normalizeHtml } from 'html-to-oft';

normalizeHtml(html) prepares HTML for Outlook-oriented template generation.

htmlToText(html) creates a plain-text fallback from HTML.

CLI

html-to-oft ./email.html --subject "Promo" --to [email protected] --out promo.oft

oft-dump ./promo.oft

Compatibility

The generated files are designed for Outlook .oft workflows. Outlook rendering can vary between Outlook versions, especially around HTML tables and inline images, so templates should be checked in the target Outlook client.

License

MIT