Fill XFA PDF Forms

Fill any Adobe LiveCycle XFA form from the CLI. Solves a gap that standard PDF tools cannot address.

Why This Exists

XFA forms (Form: XFA in pdfinfo) embed data as XML inside the PDF, not as standard AcroForm fields. Tools like pdftk, pypdf, and PyPDF2 silently fail or produce empty output. This script modifies the embedded XFA XML directly.

Prerequisites

pip install pikepdf

Quick Start

SCRIPT="\x3Cskill_dir>/scripts/fill_xfa.py"

# 1) Verify the form is XFA:
pdfinfo form.pdf | grep Form  # Should show: Form: XFA

# 2) Discover field names:
python3 "$SCRIPT" fields form.pdf

# 3) Fill from JSON:
python3 "$SCRIPT" fill form.pdf -o filled.pdf -d data.json

Commands

fields — List Data Fields

python3 "$SCRIPT" fields form.pdf

Outputs sorted field names with current values and duplicate counts.

fill — Set Field Values

Three input methods — combine freely:

# Repeatable --set flags:
python3 "$SCRIPT" fill form.pdf -o out.pdf \
  --set "Eigentümer_Name=Müller" \
  --set "Eigentümer_Vorname=Anna" \
  --set "PLZ=84424"

# JSON file:
python3 "$SCRIPT" fill form.pdf -o out.pdf -d fields.json

# Stdin pipe:
printf '{"Name":"Müller","Vorname":"Anna"}' | \
  python3 "$SCRIPT" fill form.pdf -o out.pdf --stdin

JSON Data Format

{
  "Feldname": "Wert",
  "Eigentümer_Name": "Müller",
  "Datum": "2026-05-05"
}

Field names must match the XML element names in the form (discover with fields).

Duplicate Fields

Some forms reuse field names (e.g., multiple Textfeld1). Two modes:

• Same value everywhere: --set Textfeld1=3 sets all occurrences to "3"
• Different values per occurrence: Pass an array: {"Textfeld1": ["A", "B", "C"]} distributes values across duplicates (first field gets "A", second gets "B", etc.)

Limitations

• Only works with XFA forms — verify first: pdfinfo form.pdf | grep Form
• Form must not be password-protected
• Namespace restoration preserves only the first xmlns:* declaration (rarely matters)
• Some forms require manual wet-ink signature after filling

Common Use Cases

• Government registration forms (German: Behördendrucke, Landkreis forms)
• Utility company forms (waste collection, water/electricity)
• School enrollment applications
• Any Adobe LiveCycle Designer form downloaded from official websites

Example: German Waste Bin Registration

# Discover fields:
python3 "$SCRIPT" fields tonnenanmeldung_blank.pdf

# Fill from JSON (pipe to stdin):
python3 "$SCRIPT" fill tonnenanmeldung_blank.pdf -o tonnenanmeldung_filled.pdf --stdin \x3C\x3C'EOF'
{
  "Neuantrag": "1",
  "Eigentümer_Name": "Müller",
  "Eigentümer_Vorname": "Anna",
  "Eigentümer_Straße": "Hauptstraße",
  "Eigentümer_Straße_Nummer": "5",
  "Eigentümer_PLZ": "84424",
  "Eigentümer_Ort": "Isen",
  "Eigentümer_seit": "2026-01-15",
  "Grundstück_Straße": "Beispielweg",
  "Grundstück_PLZ": "85435",
  "Grundstück_Ort": "Erding",
  "Grundstück_Haus_Nummer": "12",
  "Textfeld1": "3",
  "Restmüll_ab": "07/2026",
  "Zugang_80_l": "1",
  "Bio_Zugang_80_l": "1",
  "Papier_Zugang_240_l": "1",
  "Kontoinhaber_Name": "Müller, Anna",
  "Kontoinhaber_Straße": "Hauptstraße 5",
  "Kontoinhaber_Ort": "84424 Isen",
  "Kontoinhaber_Kreditinstitut": "VR-Bank",
  "Kontoinhaber_IBAN": "DE",
  "Kontoinhaber_IBAN_Nummer": "1234567890",
  "Kontoinhaber_BIC": "GENODEF1XXX",
  "Datum": "2026-05-05"
}
EOF