zugferd

func EmbedXML ¶

func EmbedXML(inputPDFPath string, xmlContent []byte, outputPDFPath string) error

EmbedXML produces a ZUGFeRD / Factur-X PDF/A-3 by embedding the invoice XML into an existing PDF: it attaches the XML as the associated file factur-x.xml and writes the PDF/A identifier, the Factur-X document metadata, and an sRGB output intent.

The XML stays extractable as an ordinary PDF attachment, so a recipient can process either the visual PDF or the structured data.

EmbedXML adds the PDF/A-3 structure but does not repair the visual content: the input PDF must already embed its fonts and use device RGB. A PDF rendered by headless Chromium ("print to PDF") satisfies this. To confirm full conformance, validate the output with veraPDF.

func ExtractXML ¶ added in v0.5.0

func ExtractXML(pdf []byte) ([]byte, error)

ExtractXML returns the embedded e-invoice XML from a ZUGFeRD / Factur-X / XRechnung PDF. It looks for the well-known attachment names first and falls back to the only XML attachment if exactly one exists. Returns an error when the PDF carries no invoice XML — callers use that as the signal to fall back to OCR/AI extraction.