Attachments

Pass files through attachments to embed source data, supporting documents, or invoice XML. Viewers with an attachment panel list them there:

import { render } from "takumi-pdf";

const pdf = await render(invoice, {
  attachments: [
    {
      name: "factur-x.xml",
      data: xml,
      mimeType: "application/xml",
      description: "Factur-X invoice data",
      relationship: "alternative",
    },
  ],
});

relationship takes one of these values:

Electronic invoicesCopy Anchor Link

For a Factur-X or ZUGFeRD document, use PDF/A-3 and attach the invoice XML:

import { render } from "takumi-pdf";

const pdf = await render(invoice, {
  pdfa: "3b",
  metadata: { title: "Invoice 1042", creationDate: "2026-08-06" },
  attachments: [
    {
      name: "factur-x.xml",
      data: xml,
      mimeType: "application/xml",
      description: "Factur-X invoice data",
      relationship: "alternative",
    },
  ],
});

The PDF/A-3 levels require three fields on each attachment:

• mimeType
• description
• a modification date from modificationDate, or the metadata.creationDate fallback

TypeScript enforces mimeType and description under these levels. A missing date fails the render.

Levels that allow attachmentsCopy Anchor Link

Attaching the XML does not validate it or its profile. Add the profile's XMP metadata and validate the result as described in Invoices.