> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kafkalabs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# PatternScanner

> API reference for the PatternScanner class

## Overview

The `PatternScanner` class performs regex-based pattern detection to identify hardcoded secrets, PII, and other privacy issues.

## Constructor

```javascript theme={null}
new PatternScanner()
```

**Example:**

```javascript theme={null}
const PatternScanner = require('kafkacode/dist/PatternScanner');

const scanner = new PatternScanner();
```

## Methods

### scanContent(filePath, content)

Scans file content for privacy issues using regex patterns.

```javascript theme={null}
scanContent(filePath: string, content: string): Finding[]
```

**Parameters:**

* `filePath` (string): Path to the file being scanned
* `content` (string): File content to scan

**Returns:** Array of Finding objects

**Example:**

```javascript theme={null}
const fs = require('fs');
const PatternScanner = require('kafkacode/dist/PatternScanner');

const scanner = new PatternScanner();
const content = fs.readFileSync('./src/config.js', 'utf-8');
const findings = scanner.scanContent('./src/config.js', content);

console.log(`Found ${findings.length} pattern matches`);
```

## Detection Patterns

The PatternScanner uses these regex patterns:

<Tabs>
  <Tab title="Critical Patterns">
    ```javascript theme={null}
    // AWS Access Keys
    /AKIA[0-9A-Z]{16}/g

    // Private Keys
    /-----BEGIN (RSA |EC )?PRIVATE KEY-----/g

    // Stripe Keys
    /sk_live_[0-9a-zA-Z]{24}/g
    ```
  </Tab>

  <Tab title="High Severity">
    ```javascript theme={null}
    // Generic API Keys
    /api[_-]?key.*?[=:]\s*['""]([a-zA-Z0-9_\-]+)['""]$/gmi

    // OAuth Tokens
    /ghp_[a-zA-Z0-9]{36}/g  // GitHub
    /glpat-[a-zA-Z0-9\-_]{20}/g  // GitLab
    ```
  </Tab>

  <Tab title="Medium Severity">
    ```javascript theme={null}
    // Email Addresses
    /[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}/g

    // Phone Numbers
    /\+?[1-9]\d{1,14}/g

    // High Entropy Strings
    // Calculated programmatically
    ```
  </Tab>

  <Tab title="Low Severity">
    ```javascript theme={null}
    // IP Addresses
    /\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b/g

    // URLs
    /https?:\/\/[^\s]+/g
    ```
  </Tab>
</Tabs>

## Usage Examples

### Basic Pattern Scanning

```javascript theme={null}
const PatternScanner = require('kafkacode/dist/PatternScanner');

const scanner = new PatternScanner();
const code = `
  const apiKey = "AKIAIOSFODNN7EXAMPLE";
  const email = "admin@company.com";
`;

const findings = scanner.scanContent('test.js', code);

findings.forEach(finding => {
  console.log(`${finding.severity}: ${finding.description}`);
});
```

### Custom Pattern Detection

```javascript theme={null}
class CustomScanner extends PatternScanner {
  constructor() {
    super();

    // Add custom patterns
    this.patterns.customSecret = {
      regex: /MY_SECRET_[A-Z0-9]{16}/g,
      severity: 'critical',
      type: 'Custom Secret',
      recommendation: 'Move to environment variables'
    };
  }
}

const scanner = new CustomScanner();
const findings = scanner.scanContent('file.js', content);
```

## Next Steps

<CardGroup cols={2}>
  <Card title="LLMAnalyzer" icon="brain" href="/api-reference/llm-analyzer">
    AI-powered contextual analysis
  </Card>

  <Card title="Detection Methods" icon="shield-check" href="/concepts/detection-methods">
    Learn about detection patterns
  </Card>
</CardGroup>