Merge Multiple PDF Files with CustomJS API

This n8n template demonstrates how to download multiple PDF files from public URLs and merge them into a single PDF using the PDF Toolkit from www.customjs.space.

@custom-js/n8n-nodes-pdf-toolkit

Notice

Community nodes can only be installed on self-hosted instances of n8n.

What this workflow does

• Downloads each PDF using an HTTP Request.
• Populates files into an array with Merge node from n8n.
• Merges all downloaded PDFs using the Merge PDF node from the @custom-js/n8n-nodes-pdf-toolkit.
• Writes the final merged PDF to disk.

Requirements

• Self-hosted n8n instance
• CustomJS API key for merging multiple PDF files.
• PDF files to be merged to be converted into a PDF

Workflow Steps:

1. Manual Trigger:

   • Runs with user interaction.

2. HTTP Request Node For PDF Download:

   • Pass urls for PDF files to merge.

3. Merge Node For Array Population:

   • Just populates two files into an array.

4. Merge PDF files:

   • Uses the CustomJS node to merge the incoming PDF files into a single PDF file.
   • If size of PDF files exceeds 6MB, you can simply pass an array of URLs for PDF files.

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Usage

Get API key from customJS

• Sign up to customJS platform.
• Navigate to your profile page
• Press "Show" button to get API key

Set Credentials for CustomJS API on n8n

Copy and paste your API key generated from CustomJS here.

Design workflow

• A Manual Trigger for starting workflow.
• Two HTTP Request Nodes for downloading PDF files.
• A Merge Node for populating files as an array.
• Merge PDFs node for merging files
• Write to Disk node for saving merged PDF file.

You can replace logic for triggering and returning results. For example, you can trigger this workflow by calling a webhook and get a result as a response from webhook. Simply replace Manual Trigger and Write to Disk nodes.

Perfect for

• Bundling reports or invoices.
• Generating document sets from external sources.
• Automating PDF handling without writing custom code