# Regex Safety & Performance Analyzer MCP for AI Agents MCP

> Regex Safety & Performance Analyzer identifies ReDoS vulnerabilities and catastrophic backtracking in regular expressions. It uses AST traversal to find dangerous nested quantifiers and overlapping alternatives, helping you prevent application crashes caused by malicious or poorly written patterns before they reach production.

## Overview
- **Category:** developer-tools
- **Price:** Free
- **Endpoint:** https://edge.vinkius.com/vk_preview_kSWedwC9ZlZmVtOyK83BXVelMk1nxklzWcvmbJzX/mcp
- **Tags:** regex, security, redos, performance, ast, vulnerability-scanner

## Description

You have likely dealt with a regex that works perfectly on small test strings but hangs your entire application when it hits a specific input. This is the nightmare of Regular Expression Denial of 1Service (ReDoS) attacks. Instead of relying on trial and error, this MCP lets your agent look at the structural logic of any pattern. It parses patterns into an abstract syntax tree to find flaws like nested quantifiers without ever executing the code. By connecting through Vinkius, you can integrate these deep security audits directly into your development workflow. You get a clear view of how structural relationships between elements create risk, allowing you to fix vulnerabilities before they become production outages.

## Tools

### analyze_regex_pattern
Performs a deep security audit on a specific regular expression pattern. It finds structural flaws like nested quantifiers.

### compare_patterns_safety
Determines which of two regex patterns is more performance-resilient. Use this to choose the safest option for production code.

### classify_risk_level
Converts a raw numerical risk score into a human-readable security classification. It makes complex audit data easy to understand.

## Prompt Examples

**Prompt:** 
```
Is this regex safe: (a+)+?
```

**Response:** 
```
**Security Audit Result**

* **Pattern:** `(a+)+` 
* **Status:** ⚠️ High Risk
* **Issue Found:** Nested quantifier detected at index 3.
* **Risk Score:** 0.95

This pattern is highly susceptible to catastrophic backtracking.
```

**Prompt:** 
```
Which regex is safer: (a|a) or (a+)?
```

**Response:** 
```
**Comparison Summary**

The safer pattern is: `(a+)` 

**Details:**
* **Winner:** `(a+)` 
* **Risk Difference:** 0.0
* **Reasoning:** The alternative group in the first pattern creates unnecessary complexity.
```

**Prompt:** 
```
What is the risk level for this pattern?
```

**Response:** 
```
**Risk Classification**

* **Pattern:** `[a-zA-Z0-9]+@.+` 
* **Classification:** 🔴 Critical
* **Recommendation:** Immediate refactor required. The pattern contains elements that could lead to ReDoS.
```

## Capabilities

### Identify ReDoS vulnerabilities
Find dangerous patterns that cause catastrophic backtracking.

### Compare regex resilience
Determine which of two patterns is safer for production use.

### Translate risk scores
Turn raw numerical data into clear security classifications.

### Audit pattern structure
Inspect the structural relationship of regex elements using AST traversal.

## Use Cases

### Auditing a new feature
A developer is unsure if a new validation pattern is safe. They ask their agent to run `analyze_regex_pattern` and find a high-risk nested quantifier.

### Refactoring legacy code
An engineer needs to replace an old, slow regex. They use `compare_patterns_safety` to ensure the new version is more resilient.

### Security compliance checks
A security auditor uses `classify_risk_level` to quickly categorize a list of patterns as 'Critical' or 'Safe'.

## Benefits

- Prevent application crashes by catching catastrophic backtracking early.
- Identify structural vulnerabilities using `analyze_regex_pattern` without running the code.
- Choose the most resilient production code with `compare_patterns_safety`.
- Understand security threats clearly via `classify_risk_level` classifications.
- Reduce manual testing time by automating regex security audits.

## How It Works

The bottom line is you stop deploying patterns that can crash your services.

1. Connect the Regex Safety & Performance Analyzer MCP to your preferred AI client.
2. Provide a regular expression pattern you want to audit.
3. Receive a detailed breakdown of structural risks and security classifications.

## Frequently Asked Questions

**How does Regex Safety & Performance Analyzer prevent crashes?**
It identifies structural patterns like nested quantifiers that cause the regex engine to loop excessively, preventing service outages.

**Can I use Regex Safety & Performance Analyzer with Claude?**
Yes, you can connect this MCP to any compatible client like Claude or Cursor to audit your patterns directly in your chat interface.

**Does Regex Safety & Performance Analyzer check for syntax errors?**
It focuses on security and performance risks like ReDoS rather than simple syntax validation, though it must parse the pattern correctly to work.

**Is Regex Safety & Performance Analyzer useful for production code?**
Absolutely. It helps you verify that your patterns are resilient against malicious inputs before they are deployed to live environments.

**How do I know if a pattern is dangerous using Regex Safety & Performance Analyzer?**
The tool provides a risk score and a human-readable classification so you can immediately see if a pattern is safe or critical.

**What is catastrophic backtracking?**
It is a performance failure where the engine explores every possible permutation of matches, causing exponential growth in computation time relative to input length.

**How does this tool identify vulnerabilities?**
The `analyze_regex_pattern` tool parses the pattern into an AST to find structural flaws like nested quantifiers or overlapping alternatives.

**Can I compare two different regex patterns?**
Yes, use the `compare_patterns_safety` tool to determine which pattern is more performance-resilient and see the risk difference.