README

Keep PII out of LLMs. Cloak masks sensitive data before sending text to AI APIs like ChatGPT or Claude, then restores the original data in responses.

Quick Start

// Mask PII before sending to an LLM
$safe = cloak('Contact john@example.com or call 555-123-4567');
// "Contact {{EMAIL_x7k2m9_1}} or call {{PHONE_x7k2m9_1}}"

// Restore the original data
$original = uncloak($safe);
// "Contact john@example.com or call 555-123-4567"

Why Cloak?

When building AI-powered features, user messages often contain sensitive information—emails, phone numbers, SSNs, credit cards. Sending this data to third-party LLM APIs creates privacy and compliance risks.

Cloak solves this by:

1. Detecting PII using built-in or custom detectors
2. Replacing sensitive data with placeholder tokens
3. Storing the mapping temporarily (in-memory or cache)
4. Restoring original data when you receive the LLM's response

The LLM never sees the actual PII, but your users get personalized responses.

Installation

composer require dynamik-dev/cloak-laravel

Optionally publish the config file:

php artisan vendor:publish --tag="cloak-config"

Configuration

// config/cloak.php
return [
    // false (default): In-memory storage, auto-cleared after request
    // true: Cache storage, persists across requests
    'persist' => env('CLOAK_PERSIST', false),

    // Storage driver class when persist is true
    'storage_driver' => DynamikDev\Cloak\Laravel\CacheStorage::class,

    // Cache store to use (null = default cache)
    'cache_store' => env('CLOAK_CACHE_STORE'),

    // TTL for cached mappings in seconds
    'default_ttl' => env('CLOAK_DEFAULT_TTL', 3600),
];

Encryption at Rest

This Laravel adapter integrates with cloak-php v0.2.0's encryption system using Laravel's Crypt facade. All sensitive data is encrypted before being stored, providing defense in depth—even if memory or cache is compromised, the original PII remains protected.

The encryption is handled through a custom LaravelEncryptor that implements cloak-php's EncryptorInterface, using Laravel's built-in encryption for seamless integration with your application's APP_KEY.

Persist Mode

• persist: false (default) - In-memory storage with encryption. Perfect for single-request flows where you cloak → call LLM → uncloak in one request. Data is automatically garbage collected when the request ends.

• persist: true - Laravel cache storage with encryption. Use this when you need to uncloak in a different request (e.g., webhook responses, queued jobs). TTL is configurable via default_ttl.

Usage

Helper Functions

The simplest way to use Cloak:

$masked = cloak($text);
$restored = uncloak($masked);

Facade

use DynamikDev\Cloak\Laravel\Facades\Cloak;

$masked = Cloak::cloak($text);
$restored = Cloak::uncloak($masked);

Dependency Injection

use DynamikDev\Cloak\Cloak;

class ChatController extends Controller
{
    public function send(Request $request, Cloak $cloak)
    {
        $safe = $cloak->cloak($request->input('message'));
        // ...
    }
}

Real-World Example: OpenAI Integration

use OpenAI\Laravel\Facades\OpenAI;

public function chat(Request $request)
{
    $userMessage = $request->input('message');
    // "Help me email john.doe@acme.com about invoice #1234.
    //  My number is 555-867-5309 if they need to call back."

    // 1. Cloak PII before sending to OpenAI
    $safeMessage = cloak($userMessage);
    // "Help me email {{EMAIL_a1b2c3_1}} about invoice #1234.
    //  My number is {{PHONE_a1b2c3_1}} if they need to call back."

    // 2. Send to OpenAI - no PII exposed to the API
    $response = OpenAI::chat()->create([
        'model' => 'gpt-4',
        'messages' => [
            ['role' => 'system', 'content' => 'You are a helpful assistant.'],
            ['role' => 'user', 'content' => $safeMessage],
        ],
    ]);

    // 3. Get the response (LLM uses placeholders naturally)
    $aiResponse = $response->choices[0]->message->content;
    // "Here's a draft email for {{EMAIL_a1b2c3_1}}:
    //  Subject: Regarding Invoice #1234..."

    // 4. Restore PII for the user
    $finalResponse = uncloak($aiResponse);
    // "Here's a draft email for john.doe@acme.com:
    //  Subject: Regarding Invoice #1234..."

    return response()->json(['response' => $finalResponse]);
}

Built-in Detectors

Cloak automatically detects:

By default, all detectors run. To use specific detectors:

use DynamikDev\Cloak\Detector;

// Only detect emails and phones
$masked = cloak($text, [
    Detector::email(),
    Detector::phone(),
]);

// Phone detection with region hint (improves accuracy)
$masked = cloak($text, [
    Detector::phone('US'),
]);

Custom Detectors

Pattern Detector (Regex)

use DynamikDev\Cloak\Detector;

// Detect database connection strings
$masked = cloak($text, [
    Detector::pattern(
        '/mysql:\/\/[^:]+:[^@]+@[^\s]+/',
        'DB_CONNECTION'
    ),
]);

// Detect API keys
$masked = cloak($text, [
    Detector::pattern(
        '/sk-[a-zA-Z0-9]{32,}/',
        'API_KEY'
    ),
]);

Word Detector

use DynamikDev\Cloak\Detector;

// Mask specific names or terms (case-insensitive)
$masked = cloak($text, [
    Detector::words(['John Doe', 'Jane Smith', 'Acme Corp'], 'NAME'),
]);

Callback Detector

For complex detection logic:

use DynamikDev\Cloak\Detector;

$masked = cloak($text, [
    Detector::using(function (string $text) {
        // Return array of ['match' => '...', 'type' => '...']
        $matches = [];

        // Example: Find Laravel env variables
        if (preg_match_all('/\bDB_PASSWORD=\S+/', $text, $found)) {
            foreach ($found[0] as $match) {
                $matches[] = ['match' => $match, 'type' => 'ENV_VAR'];
            }
        }

        return $matches;
    }),
]);

Middleware Example

Auto-cloak sensitive data in request logs:

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Log;

class LogSafeRequests
{
    public function handle(Request $request, Closure $next)
    {
        // Log request with PII masked
        Log::info('API Request', [
            'path' => $request->path(),
            'body' => cloak(json_encode($request->all())),
        ]);

        return $next($request);
    }
}

Testing

composer test

Version Compatibility

This package has been updated to work with cloak-php v0.2.0, which includes:

• New builder pattern API for configuring Cloak instances
• Pluggable encryption system via EncryptorInterface
• Enhanced lifecycle hooks and filtering capabilities
• Simplified storage interface (TTL handling moved to storage implementations)

What Changed in v0.2.0

Architecture improvements:

• Now uses cloak-php's ArrayStore for in-memory storage (instead of custom EncryptedArrayStorage)
• Implements a LaravelEncryptor that integrates with Laravel's Crypt facade
• Service provider uses the builder pattern: Cloak::using($store)->withEncryptor($encryptor)
• Uses Cloak::resolveUsing() to integrate with Laravel's container
• Helper functions now provided by core package (Laravel-specific helpers removed)
• TTL configuration is Laravel-specific and handled within CacheStorage constructor

Container Binding Strategy (Octane-safe):

• Cloak instances use bind() - fresh instance on every resolution (prevents state pollution)
• StoreInterface uses singleton() - shared storage for placeholder mappings
• EncryptorInterface uses singleton() - stateless encryption service

This architecture prevents issues with filters, callbacks, and other stateful configurations, especially in Laravel Octane environments where state can leak between requests.

Breaking changes from previous versions:

• EncryptedArrayStorage class has been removed (now uses core ArrayStore with LaravelEncryptor)
• StoreInterface::put() no longer accepts $ttl parameter (moved to storage implementation constructor)
• Laravel-specific helper functions removed (now uses core package helpers via resolver)

The package maintains backward compatibility at the API level—all helpers, facades, and configuration options work the same way for end users.

Advanced Usage: Extending Cloak

The resolver pattern allows developers to customize Cloak behavior through the container:

// In your AppServiceProvider
use DynamikDev\Cloak\Cloak;
use DynamikDev\Cloak\Detector;

$this->app->extend(Cloak::class, function ($cloak, $app) {
    return $cloak->withDetectors([
        Detector::email(),
        Detector::phone('US'),
        // Add your custom detectors
    ])->filter(function ($detection) {
        // Filter out test emails
        return !str_ends_with($detection['match'], '@test.local');
    });
});

Each call to cloak() or app(Cloak::class) gets a fresh instance with your customizations, preventing state pollution across requests.

Changelog

Please see CHANGELOG for more information on what has changed recently.

Contributing

Please see CONTRIBUTING for details.

Security Vulnerabilities

Please review our security policy on how to report security vulnerabilities.

Credits

• DynamikDev
• All Contributors

License

The MIT License (MIT). Please see License File for more information.