RegexGuard -- Regex Safety & Correctness Analyzer

RegexGuard scans codebases for regex anti-patterns: catastrophic backtracking (ReDoS), portability errors across engines, correctness bugs, maintainability issues, anchoring and boundary problems, and pattern injection risks. It uses regex-based pattern matching against 90 regex-specific patterns across 6 categories, lefthook for git hook integration, and produces markdown reports with actionable remediation guidance. 100% local. Zero telemetry.

Note: RegexGuard focuses on regex patterns found in source code (JavaScript, Python, Go, Java, Ruby, shell scripts, config files). It detects anti-patterns in how regexes are written, constructed, and used.

Commands

Free Tier (No license required)

regexguard scan [file|directory]

One-shot regex safety scan of files or directories.

How to execute:

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [target]

What it does:

1. Accepts a file path or directory (defaults to current directory)
2. Discovers all source files (skips .git, node_modules, binaries, images, .min.js)
3. Runs 30 regex patterns against each file (free tier limit)
4. Calculates a regex quality score (0-100) per file and overall
5. Grades: A (90-100), B (80-89), C (70-79), D (60-69), F (<60)
6. Outputs findings with: file, line number, check ID, severity, description, recommendation
7. Exit code 0 if score >= 70, exit code 1 if regex quality is poor
8. Free tier limited to first 30 patterns (CB + PE categories)

Example usage scenarios:

• "Scan my code for regex issues" -> runs regexguard scan .
• "Check this file for ReDoS vulnerabilities" -> runs regexguard scan src/validators.ts
• "Find catastrophic backtracking patterns" -> runs regexguard scan src/
• "Check for non-portable regex syntax" -> runs regexguard scan .
• "Audit regex patterns for correctness" -> runs regexguard scan .

Pro Tier ($19/user/month -- requires REGEXGUARD_LICENSE_KEY)

regexguard scan --tier pro [file|directory]

Extended scan with 60 patterns covering backtracking, portability, correctness, and maintainability.

How to execute:

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [target] --tier pro

What it does:

1. Validates Pro+ license
2. Runs 60 regex patterns (CB, PE, CE, MA categories)
3. Detects correctness bugs like unescaped dots, bad character class ranges
4. Identifies maintainability issues: overly complex patterns, missing comments
5. Full category breakdown reporting

regexguard scan --format json [directory]

Generate JSON output for CI/CD integration.

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --format json

regexguard scan --format html [directory]

Generate HTML report for browser viewing.

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --format html

regexguard scan --category CB [directory]

Filter scan to a specific check category (CB, PE, CE, MA, AN, PI).

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --category CB

Team Tier ($39/user/month -- requires REGEXGUARD_LICENSE_KEY with team tier)

regexguard scan --tier team [directory]

Full scan with all 90 patterns across all 6 categories including anchoring and injection.

How to execute:

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --tier team

What it does:

1. Validates Team+ license
2. Runs all 90 patterns across 6 categories
3. Includes anchoring checks (missing ^/$, multiline flag gaps, \b misuse)
4. Includes pattern injection checks (unsanitized user input, DoS vectors)
5. Full category breakdown with per-file results

regexguard scan --verbose [directory]

Verbose output showing every matched line and pattern details.

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --verbose

regexguard status

Show license and configuration information.

bash "<SKILL_DIR>/scripts/dispatcher.sh" status

regexguard patterns

List all 90 detection patterns across all categories.

bash "<SKILL_DIR>/scripts/dispatcher.sh" patterns

Check Categories

RegexGuard detects 90 regex anti-patterns across 6 categories:

| Category | Code | Patterns | Description | Severity Range |

|----------|------|----------|-------------|----------------|

| Catastrophic Backtracking | CB | 15 | Nested quantifiers, exponential patterns, ReDoS vectors, overlapping greed | low -- critical |

| Portability Errors | PE | 15 | Non-POSIX features, engine-specific syntax, lookbehind gaps, Unicode escapes | low -- high |

| Correctness Errors | CE | 15 | Unescaped dots, bad character class ranges, greedy vs lazy, redundant quantifiers | low -- high |

| Maintainability Issues | MA | 15 | Overly complex patterns, missing comments, duplication, magic regex strings | low -- high |

| Anchoring & Boundaries | AN | 15 | Missing ^/$, \b misuse, multiline flag gaps, validation anchor bypass | low -- critical |

| Pattern Injection | PI | 15 | Unsanitized user input in regex, string concat into RegExp, DoS vectors | low -- critical |

Tier-Based Pattern Access

| Tier | Patterns | Categories |

|------|----------|------------|

| Free | 30 | CB, PE |

| Pro | 60 | CB, PE, CE, MA |

| Team | 90 | CB, PE, CE, MA, AN, PI |

| Enterprise | 90 | CB, PE, CE, MA, AN, PI + priority support |

Scoring

RegexGuard uses a deductive scoring system starting at 100 (perfect):

| Severity | Point Deduction | Description |

|----------|-----------------|-------------|

| Critical | -25 per finding | Severe risk (ReDoS, injection, missing validation anchors) |

| High | -15 per finding | Significant problem (portability bugs, correctness errors) |

| Medium | -8 per finding | Moderate concern (engine-specific features, maintainability) |

| Low | -3 per finding | Informational / best practice suggestion |

Grading Scale

| Grade | Score Range | Meaning |

|-------|-------------|---------|

| A | 90-100 | Excellent regex quality |

| B | 80-89 | Good patterns with minor issues |

| C | 70-79 | Acceptable but needs improvement |

| D | 60-69 | Poor regex quality |

| F | Below 60 | Critical regex problems |

• Pass threshold: 70 (Grade C or better)
• Exit code 0 = pass (score >= 70)
• Exit code 1 = fail (score < 70)

Configuration

Users can configure RegexGuard in ~/.openclaw/openclaw.json:

{
  "skills": {
    "entries": {
      "regexguard": {
        "enabled": true,
        "apiKey": "YOUR_LICENSE_KEY_HERE",
        "config": {
          "severityThreshold": "medium",
          "ignorePatterns": ["**/test/**", "**/fixtures/**", "**/*.test.*"],
          "ignoreChecks": [],
          "reportFormat": "text"
        }
      }
    }
  }
}

Important Notes

• Free tier works immediately with no configuration
• All scanning happens locally -- no code is sent to external servers
• License validation is offline -- no phone-home or network calls
• Pattern matching only -- no AST parsing, no external dependencies beyond bash
• Supports scanning all file types in a single pass
• Git hooks use lefthook which must be installed (see install metadata above)
• Exit codes: 0 = pass (score >= 70), 1 = fail (for CI/CD integration)
• Output formats: text (default), json, html

Error Handling

• If lefthook is not installed and user tries hooks, prompt to install it
• If license key is invalid or expired, show clear message with link to https://regexguard.pages.dev/renew
• If a file is binary, skip it automatically with no warning
• If no scannable files found in target, report clean scan with info message
• If an invalid category is specified with --category, show available categories

When to Use RegexGuard

The user might say things like:

• "Scan my code for regex issues"
• "Check for catastrophic backtracking"
• "Find ReDoS vulnerabilities in my patterns"
• "Check for non-portable regex syntax"
• "Audit regex correctness in my codebase"
• "Find regex injection risks"
• "Check if my validation regex has proper anchors"
• "Detect overly complex regex patterns"
• "Scan for regex portability problems"
• "Find unsafe dynamic regex construction"
• "Run a regex quality audit"
• "Generate a regex health report"
• "Check for unescaped dots in my patterns"
• "Find missing anchors in validation regex"
• "Check for user input in regex constructors"