id_doc_kit

A lightweight, production-ready Flutter/Dart package for validating Indian ID documents used in KYC, onboarding, and fintech workflows.

Built with a strict core architecture, structured results, and developer-friendly UI helpers.

🚀 Live Demo

Try it out in your browser! 👉 View Live Demo

The demo showcases all supported document types with real-time validation feedback, automatic formatting, and metadata extraction.

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✨ Supported Documents

✅ Aadhaar (12-digit UID & 16-digit VID with Verhoeff Checksum)
✅ PAN (with Holder Type detection - Individual, Company, Trust, etc.)
✅ GSTIN (with State detection)
✅ Driving License (Strict RTO rules + Legacy support + Fallback logic)
✅ Voter ID (EPIC)
✅ Passport
✅ PIN Code (India)
✅ Phone Number (India - handles +91 prefix)
✅ Email

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🛠 Key Features

• 📦 Structured Results: Returns IdDocumentResult with error codes, human-friendly messages, and metadata.
• ⌨️ Smart Formatters: Built-in TextInputFormatter for auto-spacing (Aadhaar) and case correction (PAN/GSTIN) with cursor preservation.
• 🔍 Auto Detection: Identify the document type automatically from a raw string using validateAuto.
• 🏷 Metadata Extraction: Parse state codes, RTO numbers, holder types, and issuance years.
• 💬 Friendly Messages: Pre-configured human-readable messages via the friendlyMessage extension.
• 🧠 Confidence Scores: Deterministic scoring (0.0 to 1.0) for validation certainty.

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📦 Result Structure

IdDocumentResult {
  type,            // IdDocumentType.pan, .aadhaar, etc.
  isValid,         // Boolean
  rawValue,        // Original input
  normalizedValue, // Stripped of spaces/formatting
  metadata,        // Map containing State, RTO, Holder Type, etc.
  confidence,      // 0.0 to 1.0
  errorCode,       // Machine-readable (e.g., 'PAN_INVALID_FORMAT')
  errorMessage     // Raw technical error
}

// UI Extension for human-readable feedback
print(result.friendlyMessage); // "Invalid PAN format. Example: ABCDE1234F"

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⌨️ Real-time Input Formatting

Enhance UX by applying formatters directly to your TextFormField. These formatters handle cursor position preservation and real-time cleanup.

Document	Formatting Logic	Keyboard Type
Aadhaar	1234 5678 9012 (Auto-space)	Number
PAN	ABCDE1234F (Auto-uppercase)	Text (Capitalized)
Phone	Strips non-digits, handles +91	Phone

Direct usage:

TextFormField(
  inputFormatters: [IdInputFormatters.getFormatter(IdDocumentType.aadhaar)],
  keyboardType: TextInputType.number,
);

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🎨 UI Widgets

1. IdTextField (Quickest Integration)

A specialized TextFormField that handles formatting, keyboard types, capitalization, and validation automatically.

IdTextField(
  type: IdDocumentType.pan,
  autoFormat: true,
  decoration: InputDecoration(labelText: "Enter PAN"),
  onValidationChanged: (isValid) {
    setState(() => isPanValid = isValid);
  },
)

2. IdField (Custom UI Builder)

Use this for full UI control while the library manages the logic, formatting, and result state.

IdField(
  type: IdDocumentType.aadhaar,
  builder: (context, controller, result) {
    return Column(
      children: [
        TextField(controller: controller),
        if (result != null && !result.isValid)
          Text(result.friendlyMessage, style: TextStyle(color: Colors.red)),
      ],
    );
  },
);

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🧪 Advanced Logic

Smart Auto-Detection:

// Input: "ABCDE1234F"
final result = IdValidator.instance.validateAuto(input);
print(result.type); // IdDocumentType.pan

Metadata Extraction:

final result = IdValidator.instance.validate(type: IdDocumentType.pan, value: input);

// Access parsed metadata
final holder = result.metadata?['holderType']; // 'Individual', 'Company', etc.
final state = result.metadata?['stateName'];    // 'Karnataka' (for DL/GSTIN)

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🔐 Disclaimer

This package performs format and structural validation (checksums, regex, and patterns). It does not verify the identity against government databases (UIDAI, NSDL, etc.).

☕ Support & Sponsorship

If id_doc_kit saves you development time or helps in production, consider supporting its development.