Download Documents

GET /invoices/{environment}/{ksefNumber}

Downloads an invoice document from KSeF in the selected format. Content is returned as base64-encoded string. Requires an active KSeF session.

Path Parameters

Parameter	Type	Required	Description
environment	string	✅	test, demo or prod
ksefNumber	string	✅	KSeF invoice number

Query Parameters

Parameter	Type	Default	Description
docType	string	xml	Document type

Available document types (docType)

Value	Description	Content-Type
xml	KSeF invoice XML	application/xml
pdf	Generated invoice PDF (via ksef-pdf-generator with QR)	application/pdf
qr	QR code image in PNG	image/png

info

docType=pdf generates a full PDF server-side using ksef-pdf-generator, supporting FA(1), FA(2), FA(3) and FA_RR schemas, including QR verification code.

UPO

To download UPO (Official Confirmation of Receipt), use the dedicated endpoint: GET /invoices/{environment}/status/{referenceNumber}/{ksefNumber}/upo

Response 200 — XML

{
  "ksefNumber": "1234567890-20260101-ABCDEF-12",
  "docType": "xml",
  "contentType": "application/xml",
  "content": "PD94bWwgdmVyc2lvbj0i...",
  "fileName": "1234567890-20260101-ABCDEF-12.xml"
}

Response 200 — PDF

{
  "ksefNumber": "1234567890-20260101-ABCDEF-12",
  "docType": "pdf",
  "contentType": "application/pdf",
  "content": "JVBERi0xLjQK...",
  "fileName": "1234567890-20260101-ABCDEF-12.pdf",
  "qrVerificationUrl": "https://qr-test.ksef.mf.gov.pl/invoice/..."
}

Response 200 — QR

{
  "ksefNumber": "1234567890-20260101-ABCDEF-12",
  "docType": "qr",
  "contentType": "image/png",
  "content": "iVBORw0KGgoAAAA...",
  "fileName": "1234567890-20260101-ABCDEF-12-qr.png",
  "qrVerificationUrl": "https://qr-test.ksef.mf.gov.pl/invoice/..."
}

Field	Type	Description
ksefNumber	string	KSeF invoice number
docType	string	Requested document type (xml, pdf, qr)
contentType	string	MIME type of the content
content	string	Base64-encoded document content
fileName	string	Suggested file name
qrVerificationUrl	string	QR verification URL (only for pdf and qr types)

Error Codes

Code	Description
400	Invalid docType parameter
401	Unauthorized
404	No active KSeF session or invoice not found
500	PDF generation error
502	KSeF error