PDF Letter MCP server

<!-- Author: Fabian Bitter (fabian@bitter.de) -->

pdf-letter-mcp

Local MCP server (stdio) that turns structured letter data into a print ready PDF. One fixed layout, the everyday German letter, with the recipient address positioned per DIN 5008 so it sits exactly in the window of DL and C6/C5 window envelopes. No web service, no external API, everything runs offline on your machine.

Features

• One layout, no variants: return address line, recipient, right aligned "place, date", bold subject block with references below it, salutation, body, closing, signature, enclosures
• Address field 45 mm high ending at 105 mm from the left, with return address line, remark zone (Einschreiben, Nicht nachsenden) and address zone
• Return address, remarks and recipient are balanced inside the address field, so the block sits evenly in the envelope window and further address lines still fit. addressLayout: "din" switches back to the fixed zone boundaries
• Page breaks keep closing, signature image, name and enclosures together, follow-up pages carry recipient, date and page number
• Subject 33 mm below the address field, place and date three lines above it
• Fold marks at 105 mm and 210 mm, punch mark at 148.5 mm
• DIN 5008 writing margin of 25 mm on the left, and the address field follows it, so address, subject and body share one edge. The field keeps its right edge at 105 mm and stays inside the 90 mm envelope window
• Closing, one blank line, printed name. signature.spaceMm reserves more room for signing by hand
• Signature as an image file: PNG with alpha channel keeps its transparency, the image is laid over the blank line above the printed name and never shifts the text. Optional crop, background removal and ink recolouring for scans
• Multilingual: de, en, fr, es, it, nl, pt, pl, tr, da, sv, cs with locale aware date formats and address rules per country
• Language aware hyphenation, bold/italic markup, bullet and numbered lists, automatic page breaks with continuation headers
• Page numbers and a layout debug mode that draws the DIN 5008 zones

Install

npm install
npm run build

Register the server in Claude Code:

claude mcp add pdf-letter -- node "/absolute/path/to/pdf-letter-mcp/dist/src/index.js"

Or in ~/.claude.json / claudedesktopconfig.json:

{
  "mcpServers": {
    "pdf-letter": {
      "command": "node",
      "args": ["/absolute/path/to/pdf-letter-mcp/dist/src/index.js"],
      "env": {
        "PDF_LETTER_OUTPUT_DIR": "~/Documents/Briefe"
      }
    }
  }
}

Environment

Sender profiles

Sender addresses and signatures live in a file on the machine, never in the prompt. A letter names a profile, the server fills in address, return address line and signature image verbatim.

{
  "defaultProfile": "erika",
  "profiles": {
    "erika": {
      "description": "Erika Musterfrau, privat",
      "sender": {
        "name": "Erika Musterfrau",
        "street": "Musterstraße 12",
        "postalCode": "12345",
        "city": "Musterstadt",
        "country": "DE"
      },
      "place": "Musterstadt",
      "locale": "de",
      "signature": { "path": "/pfad/zur/unterschrift.png" }
    }
  }
}

Shortened. The full README is on GitHub.