PDF Generator

When to Use This Skill

Use this skill when:

• Creating PDF documents programmatically from data or specifications

• Filling PDF forms with dynamic data

• Adding watermarks, stamps, or overlays to existing PDFs

• Extracting text and metadata from PDF files

• Merging multiple PDFs into one document

• Analyzing PDF structure and form fields

Do NOT use this skill when:

• User wants to open/view PDFs (use native PDF viewer)

• Complex page layout with flowing text is needed (consider HTML-to-PDF tools)

• Working with password-protected PDFs (limited support)

• OCR is needed for scanned documents

Prerequisites

• Deno installed (https://deno.land/)

• Input PDF files for template-based operations

• JSON specification for scratch generation

Quick Start

Two Modes of Operation

-

Template Mode: Modify existing PDF templates

• Fill form fields (text, checkbox, dropdown)

• Add overlays (text, images, shapes)

• Merge and combine PDFs

-

Scratch Mode: Create PDFs from nothing using JSON specifications

Instructions

Mode 1: Template-Based Generation

#### Step 1a: Analyze the Template

Extract form fields and structure from an existing PDF:

deno run --allow-read scripts/analyze-template.ts form-template.pdf > inventory.json

Output (inventory.json):

{

  "filename": "form-template.pdf",

  "pageCount": 2,

  "title": "Application Form",

  "author": "Company Inc",

  "pages": [

    { "pageNumber": 1, "width": 612, "height": 792, "text": "..." }

  ],

  "formFields": [

    { "name": "FullName", "type": "text", "value": "" },

    { "name": "Email", "type": "text", "value": "" },

    { "name": "AgreeToTerms", "type": "checkbox", "value": false }

  ],

  "placeholders": [

    { "tag": "{{DATE}}", "location": "page 1", "pageNumber": 1 }

  ],

  "hasFormFields": true

}

#### Step 1b: Create Fill Specification

Create form-data.json:

{

  "formFields": [

    { "name": "FullName", "value": "John Smith" },

    { "name": "Email", "value": "john@example.com" },

    { "name": "AgreeToTerms", "value": true }

  ],

  "flattenForm": true

}

#### Step 1c: Generate Filled PDF

deno run --allow-read --allow-write scripts/generate-from-template.ts \

  form-template.pdf form-data.json filled-form.pdf

Adding Overlays (Watermarks, Stamps)

Create watermark-spec.json:

{

  "overlays": [

    {

      "type": "text",

      "page": 1,

      "x": 200,

      "y": 400,

      "text": "CONFIDENTIAL",

      "fontSize": 48,

      "color": { "r": 1, "g": 0, "b": 0 },

      "rotate": 45

    },

    {

      "type": "image",

      "page": 1,

      "x": 450,

      "y": 700,

      "path": "logo.png",

      "width": 100,

      "height": 50

    }

  ]

}

Merging PDFs

Create merge-spec.json:

{

  "prependPdfs": [

    { "path": "cover-page.pdf" }

  ],

  "appendPdfs": [

    { "path": "appendix-a.pdf", "pages": [1, 2, 3] },

    { "path": "appendix-b.pdf" }

  ],

  "excludePages": [5, 6]

}

Mode 2: From-Scratch Generation

#### Step 2a: Create Specification

Create spec.json:

{

  "title": "Quarterly Report",

  "author": "Finance Team",

  "pages": [

    {

      "size": "A4",

      "elements": [

        {

          "type": "text",

          "x": 50,

          "y": 750,

          "text": "Q4 2024 Financial Report",

          "fontSize": 28,

          "font": "HelveticaBold",

          "color": { "r": 0, "g": 0, "b": 0.5 }

        },

        {

          "type": "line",

          "startX": 50,

          "startY": 740,

          "endX": 550,

          "endY": 740,

          "thickness": 2

        },

        {

          "type": "text",

          "x": 50,

          "y": 700,

          "text": "Executive Summary",

          "fontSize": 18,

          "font": "HelveticaBold"

        },

        {

          "type": "text",

          "x": 50,

          "y": 670,

          "text": "This quarter showed strong growth across all divisions...",

          "fontSize": 12,

          "maxWidth": 500,

          "lineHeight": 16

        }

      ]

    }

  ]

}

#### Step 2b: Generate PDF

deno run --allow-read --allow-write scripts/generate-scratch.ts spec.json output.pdf

Examples

Example 1: Fill Application Form

Scenario: Automatically fill a job application form.

# 1. Analyze form to find field names

deno run --allow-read scripts/analyze-template.ts application.pdf --pretty

# 2. Create form-data.json with applicant info

# 3. Generate filled form

deno run --allow-read --allow-write scripts/generate-from-template.ts \

  application.pdf form-data.json john-smith-application.pdf

Example 2: Add Approval Stamp

Scenario: Add an "APPROVED" stamp to a document.

stamp-spec.json:

{

  "overlays": [

    {

      "type": "rectangle",

      "page": 1,

      "x": 400,

      "y": 700,

      "width": 150,

      "height": 50,

      "color": { "r": 0.9, "g": 1, "b": 0.9 }

    },

    {

      "type": "text",

      "page": 1,

      "x": 410,

      "y": 720,

      "text": "APPROVED",

      "fontSize": 20,

      "font": "HelveticaBold",

      "color": { "r": 0, "g": 0.5, "b": 0 }

    },

    {

      "type": "text",

      "page": 1,

      "x": 410,

      "y": 705,

      "text": "2024-12-15",

      "fontSize": 10

    }

  ]

}

Example 3: Create Report with Table

Scenario: Generate a simple report with a data table.

report-spec.json:

{

  "title": "Sales Report",

  "pages": [{

    "size": "Letter",

    "elements": [

      {

        "type": "text",

        "x": 72,

        "y": 720,

        "text": "Monthly Sales Report",

        "fontSize": 24,

        "font": "HelveticaBold"

      },

      {

        "type": "table",

        "x": 72,

        "y": 680,

        "rows": [

          ["Product", "Units", "Revenue"],

          ["Widget A", "150", "$15,000"],

          ["Widget B", "75", "$11,250"],

          ["Widget C", "200", "$8,000"]

        ],

        "columnWidths": [150, 80, 100],

        "rowHeight": 25,

        "headerBackground": { "r": 0.9, "g": 0.9, "b": 0.9 }

      }

    ]

  }]

}

Script Reference

Script

Purpose

Permissions

analyze-template.ts

Extract text, metadata, form fields from PDF

--allow-read

generate-from-template.ts

Fill forms, add overlays, merge PDFs

--allow-read --allow-write

generate-scratch.ts

Create PDF from JSON specification

--allow-read --allow-write

Element Types (Scratch Mode)

Type

Description

Key Options

text

Text content

x, y, text, fontSize, font, color, rotate

image

PNG/JPEG images

x, y, path, width, height, opacity

rectangle

Filled/outlined rectangles

x, y, width, height, color, borderColor

line

Straight lines

startX, startY, endX, endY, thickness

circle

Filled/outlined circles

x, y, radius, color, borderColor

table

Basic table layout

x, y, rows, columnWidths, rowHeight

Available Fonts

• Helvetica (default)

• HelveticaBold

• HelveticaOblique

• TimesRoman

• TimesBold

• Courier

• CourierBold

Page Sizes

• A4 (595.28 x 841.89 points)

• Letter (612 x 792 points)

• Legal (612 x 1008 points)

• Custom: [width, height] in points

Common Issues and Solutions

Issue: Form fields not found

Symptoms: Error saying field name doesn't exist.

Solution:

• Run analyze-template.ts to get exact field names

• Field names are case-sensitive

• Some PDFs have non-fillable text that looks like form fields

Issue: Text positioning is off

Symptoms: Text appears in wrong location.

Solution:

• PDF coordinates start from bottom-left (0,0)

• Y increases upward, X increases rightward

• Use analyze-template.ts to see page dimensions

Issue: Images not appearing

Symptoms: Image overlay not visible.

Solution:

• Check file path is relative to spec.json location

• Verify image is PNG or JPEG format

• Ensure coordinates are within page bounds

Issue: Merged PDF has wrong page order

Symptoms: Pages appear in unexpected order.

Solution:

• prependPdfs add pages before template

• appendPdfs add pages after template

• Use pages array to select specific pages: [1, 3, 5]

Limitations

• No built-in table layout: Tables require manual column width specification

• Standard fonts only: Custom font embedding not supported in scratch mode

• No flowing text: Text doesn't automatically wrap to next page

• Limited form field creation: Can fill existing forms, not create new fields

• No encryption: Cannot create password-protected PDFs

• Basic graphics: No gradients, patterns, or complex paths

• Text extraction: May not work perfectly on all PDFs (depends on PDF structure)

Related Skills

• pptx-generator: For creating PowerPoint presentations

• docx-generator: For creating Word documents

• xlsx-generator: For creating Excel spreadsheets