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extracting-form-fields

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Extract form field data from PDFs as a first step to filling PDF forms

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Marketplace

Chatfield

jhs/Chatfield

Plugin

filling-pdf-forms

Repository

jhs/Chatfield
5stars

Claude/filling-pdf-forms/skills/extracting-form-fields/SKILL.md

Last Verified

January 21, 2026

Install Skill

Select agents to install to:

Scope:
npx add-skill https://github.com/jhs/Chatfield/blob/main/Claude/filling-pdf-forms/skills/extracting-form-fields/SKILL.md -a claude-code --skill extracting-form-fields

Installation paths:

Claude
.claude/skills/extracting-form-fields/
Powered by add-skill CLI

Instructions

# Extracting Form Fields

Prepare working directory and extract field data from PDF forms.

<purpose>
This skill extracts PDF form information into useful JSON.
- Detects fillable vs. non-fillable PDFs
- Extracts PDF content as readable Markdown
- Creates field metadata in common JSON format
</purpose>

## Inputs

- **PDF path**: Path to PDF file (e.g., `/home/user/input.pdf`)

## Process Overview

```plantuml
@startuml SKILL
title Extracting Form Fields - High-Level Workflow
start
:Create working directory;
:Copy interview template;
:Extract PDF content as Markdown;
:Check Fillability;
if (PDF has fillable fields?) then (yes)
  :Fillable workflow
  (see Fillable-Forms.md);
else (no)
  :Non-fillable workflow
  (see Nonfillable-Forms.md);
endif
:**✓ EXTRACTION COMPLETE**;
:Ready for Form Data Model creation;
stop
@enduml
```

## Process

### 1. Create Working Directory

```bash
mkdir <basename>.chatfield
```

### 2. Copy Interview Template

Copy a file from the included `filling-pdf-forms` skill's template. The example path below is relative to this skill directory.

```bash
cp ../filling-pdf-forms/scripts/chatfield_interview_template.py <basename>.chatfield/interview.py
```

### 3. Extract PDF Content

```bash
markitdown <pdf_path> > <basename>.chatfield/<basename>.form.md
```

### 4. Check Fillability

```bash
python scripts/check_fillable_fields.py <pdf_path>
```

**Output:**
- `"This PDF has fillable form fields"` → use fillable workflow
- `"This PDF does not have fillable form fields"` → use non-fillable workflow

### 5. Branch Based on Fillability

#### If Fillable:

Follow ./references/Fillable-Forms.md

#### If Non-fillable:

Follow ./references/Nonfillable-Forms.md

## Output Format

### Fillable PDFs - .form.json

```json
[
  {
    "field_id": "topmostSubform[0].Page1[0].f1_01[0]",
    "type": "text",
    "page": 1,
    "rect": [100, 200, 300, 220],
    "tooltip": "Enter your full legal name",
    "max_length": null
  },
  {
    "field_id": "checkbox_over_1

Validation Details

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Instruction Length:
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