n8n-nodes-pdf-text

An n8n community node that inserts text at precise X/Y positions into existing PDF files using pdf-lib.

Perfect for stamping values onto pre-made form templates — invoices, expense forms, certificates, contracts — without rebuilding the document.

Features

• Takes a PDF as binary input from any upstream node (configurable binary property, default data).
• Add multiple text fields — each with its own text, position, size, font and color.
• Text supports n8n expressions, so you can map values from previous nodes.
• Choose the target page (or apply to all pages).
• Outputs the modified PDF as binary (configurable property, default data).

Installation

Community Nodes (recommended)

1. In your n8n instance go to Settings → Community Nodes.

2. Click Install.

3. Enter the package name / GitHub URL:

   https://github.com/x88a9/pdflib-custom-node

4. Agree to the risks and click Install.

After installation the PDF Text node is available in the node panel.

n8n must be configured to allow installing community nodes (N8N_COMMUNITY_PACKAGES_ENABLED=true, which is the default).

Manual / self-hosted

cd ~/.n8n/nodes        # or your custom nodes folder
npm install https://github.com/x88a9/pdflib-custom-node

Then restart n8n.

Node configuration

| Field | Description | | --- | --- | | Input Binary Property | Name of the binary property on the incoming item holding the source PDF (default data). | | Text Fields | One or more text entries to draw (see below). | | Page Number | 1-based page to draw on. Use 0 to apply text to all pages. | | Output Binary Property | Name of the binary property to write the result to (default data). | | Output File Name | File name for the resulting PDF. .pdf is appended automatically if omitted (so invoice and invoice.pdf both produce invoice.pdf). If left empty, the input file name is reused with an _edited suffix (e.g. report.pdf → report_edited.pdf). |

The output item contains only the generated PDF — the original input file is not carried through.

Each Text Field has:

| Property | Description | | --- | --- | | Text | The text to insert (supports expressions). | | X (pt from left) | Horizontal position in points from the left edge. | | Y (pt from bottom) | Vertical position in points from the bottom edge. | | Font Size | Font size in points. | | Font | Helvetica, Helvetica Bold, Times Roman, or Courier. | | Color | Hex color string, e.g. #000000. |

Coordinate system

pdf-lib uses a coordinate system where the origin (0, 0) is the bottom-left corner of the page. This is the opposite of most screen/image coordinate systems where (0, 0) is the top-left.

 (0, height) ┌───────────────┐ (width, height)
             │               │
             │   Y increases │
             │      ↑        │
             │               │
      (0, 0) └───────────────┘ (width, 0)
              X increases →

• X grows to the right.
• Y grows upward — a larger Y moves the text higher on the page.

Common page sizes (in points, 1 pt = 1/72 inch):

| Size | Width | Height | | --- | --- | --- | | A4 | 595 | 842 | | Letter | 612 | 792 |

So to place text near the top of an A4 page, use a large Y value (e.g. Y ≈ 800); near the bottom, use a small Y (e.g. Y ≈ 40).

Example: German expense form (Spesenformular)

Suppose you have an A4 template (595 × 842 pt) with labels printed on it and you want to fill in the values next to each label. Approximate coordinates:

| Feld | Text (example) | X | Y | Font Size | Font | | --- | --- | --- | --- | --- | --- | | Beantrager | {{$json.name}} | 180 | 760 | 11 | Helvetica | | Datum | {{$json.datum}} | 180 | 730 | 11 | Helvetica | | Betrag | {{$json.betrag}} € | 180 | 700 | 11 | Helvetica-Bold | | Anzahl | {{$json.anzahl}} | 180 | 670 | 11 | Helvetica | | Verwendungszweck | {{$json.zweck}} | 180 | 640 | 11 | Helvetica |

Remember: because Y is measured from the bottom, the first row (Y = 760) sits near the top of the page and each subsequent row steps down by 30 pt.

Tip: the exact X/Y values depend on your template. Start with rough values, run the workflow, open the output PDF, and nudge the numbers until the text lands where you want it.

Development

npm install
npm run build      # compiles TypeScript to dist/ and copies assets

The compiled output in dist/ is committed to the repository so the package can be installed directly from GitHub without a build step.

License

MIT