pdf-filler-mcp

An MCP server that lets Claude fill any PDF form — scanned or AcroForm — through a browser-based drag-and-drop editor.

Editor — drag, reposition and edit fields directly on the rendered PDF page:

Result — the generated PDF with all fields overlaid:

How it works

1. Claude renders the PDF to images and inspects the layout
2. Claude places markers on each field and iterates until placement is correct
3. Claude opens the editor — a self-contained HTML page where you drag fields, edit values and click Fertig
4. PDF is generated automatically — the editor POSTs to a local receiver which runs headless Playwright to produce the final PDF

The entire stack runs locally. No data leaves your machine.

Tools exposed

Tool	Description
pdf_render	Render all pages to PNG at a given DPI, returns scale factor
pdf_preview	Overlay numbered coloured marker dots on a page for iterative placement verification
pdf_editor_multi	Generate a multi-page drag-and-drop HTML editor pre-filled with field values
pdf_fill	Directly overlay text on a PDF without opening the browser editor
pdf_merge	Merge per-page PDFs into a single file
pdf_memory_get	Retrieve saved field layout for a known form type
pdf_memory_set	Save verified field layout so the same form can be filled again instantly
pdf_receiver_start	Start the local HTTP receiver that auto-generates the PDF on Fertig
pdf_receiver_wait	Block until the user clicks Fertig and the PDF is ready

Prerequisites

• Python 3.9+
• pymupdf (pip install pymupdf)
• pypdf (pip install pypdf) — for merging
• Node.js + Playwright — for the auto-PDF-generation step (npm i -g playwright)

Installation

1. Clone

git clone https://github.com/patroqueeet/pdf-filler-mcp.git ~/.claude/pdf-filler

2. Register with Claude Code

Add to ~/.mcp.json:

{
  "mcpServers": {
    "pdf-filler": {
      "command": "python3",
      "args": ["~/.claude/pdf-filler/filler.py", "serve"]
    }
  }
}

Restart Claude Code — the pdf_* tools will be available in any session.

Typical workflow

User: Fill out /tmp/application.pdf with my personal data

Claude:
  1. pdf_render       → get page images + scale_factor
  2. pdf_preview      → place marker dots, read result image, adjust
  3. pdf_memory_get   → check if layout is already saved
  4. pdf_receiver_start → start PDF receiver on port 7789
  5. pdf_editor_multi → open editor in browser
  6. pdf_receiver_wait → wait for user to click Fertig
  → returns: { done: true, output_path: "/tmp/application_filled.pdf" }

Editor features

• Click to create a field anywhere on the document image
• Drag the ⣿ handle to reposition
• Tab between fields; inline editing
• Checkbox type available via the ➕ button
• Multi-page navigation with per-page field state
• Print CSS hides all editor chrome — only text overlays are printed

Running the tests

pip install pymupdf pypdf pytest pytest-timeout
pytest tests/ -v

License

MIT — see LICENSE.