N8n-nodes-pdf-merger NPM

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

Clone the repository:

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

Navigate to the directory:
```
	cd n8n-nodes-pdf-merger
	```
```
Install dependencies and build:
```
	pnpm install && pnpm run build
	```
```
Copy the build to your n8n custom nodes folder:
```
	cp -r dist/ ~/.n8n/custom/
	```
```

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

Provide two PDFs to your workflow:
- One as house style (binary property binaryData1).
- One as content (binary property binaryData2).
Add the PDF Merger Node and configure the property names if needed.
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

Load PDFs: The node uses pdf-lib to load the house style and content PDFs.
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.
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.
Fallback Sizes: If a PDF has no pages, the node defaults to an A4-ish size (595 × 842).