PDF Merger Node for n8n

A custom node to merge two PDF files in your n8n workflows. Overlay the first page of a house-style PDF behind all pages of a content PDF, with fallback handling for missing or single-page PDFs.

📖 Overview

The PDF Merger Node allows you to:

• Overlay a "house style" PDF onto a "content" PDF by using only the first page of the house style as a background for all content pages.
• Always draw the content on top of the house style.
• Handle differences in page counts gracefully, defaulting to A4-size if no pages exist in either PDF.
• Output a single merged PDF file.

🛠️ Node Configuration

Inputs

• House Style PDF: Binary property for the house style file (default: binaryData1).
• Content PDF: Binary property for the content file (default: binaryData2).

Additional Options

• Output File Name: Name used when storing the merged PDF (default: merged.pdf).
• Output Binary Property: Binary property name where the merged PDF is saved (default: mergedPdf).

Output

• Merged PDF: The combined PDF file as a binary property in the item.

🚀 Installation

Step-by-Step Guide

1. Clone the repository:

     git clone https://github.com/silverkey-it/n8n-nodes-pdf-merger.git
     ```

2. Navigate to the directory:

     cd n8n-nodes-pdf-merger
     ```

3. Install dependencies and build:

     pnpm install && pnpm run build
     ```

4. Copy the build to your n8n custom nodes folder:

     cp -r dist/ ~/.n8n/custom/
     ```

5. Restart your n8n instance:

     # If n8n is currently running, stop it first, then start.
     n8n stop && n8n start
     ```
   or just start it if it was not running:
   ```bash
     n8n start
     ```
   

🏗️ Example Workflow

1. Provide two PDFs to your workflow:
   • One as house style (binary property binaryData1).
   • One as content (binary property binaryData2).
2. Add the PDF Merger Node and configure the property names if needed.
3. Execute the workflow, and the node will produce:
   • A single merged PDF in the binary property you specify (default: mergedPdf).

⚙️ How It Works Under the Hood

1. Load PDFs: The node uses pdf-lib to load the house style and content PDFs.
2. Embed Only the First Page of the House Style: Even if your house style has multiple pages, only page 1 is used as the background.
3. Iterate Over Content Pages: For each content PDF page, the node:
   • Creates a new page in the output PDF.
   • Draws the background (house style) first.
   • Draws the content page on top.
4. Fallback Sizes: If a PDF has no pages, the node defaults to an A4-ish size (595 × 842).

License

This project is licensed under the MIT License. Feel free to use, modify, and distribute as needed.

Contributing

Contributions are welcome! Feel free to open an issue or submit a pull request.

Happy merging! 🎉