regex-tools-mcp

A powerful MCP server providing regex utilities for AI coding agents to test, extract, replace, explain, and generate regular expressions.

Installation

Using npx (Recommended)

npx regex-tools-mcp

Using npm

npm install -g regex-tools-mcp

MCP Client Configuration

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "regex-tools-mcp": {
      "command": "npx",
      "args": ["-y", "regex-tools-mcp"]
    }
  }
}

Cursor

Add to your MCP settings:

{
  "mcpServers": {
    "regex-tools-mcp": {
      "command": "npx",
      "args": ["-y", "regex-tools-mcp"]
    }
  }
}

Windsurf

Add to your MCP configuration:

{
  "mcpServers": {
    "regex-tools-mcp": {
      "command": "npx",
      "args": ["-y", "regex-tools-mcp"]
    }
  }
}

Tools

test_pattern

Test a regex pattern against a string and get match results.

Input: pattern="^\d{3}-\d{2}-\d{4}$", text="123-45-6789"
Output: { matches: true, result: "123-45-6789" }

extract_matches

Extract all matches of a pattern from text.

Input: pattern="\b\w+@\w+\.\w+\b", text="Contact: [email protected] or [email protected]"
Output: { matches: ["[email protected]", "[email protected]"] }

replace_pattern

Replace text matching a pattern with a replacement string.

Input: pattern="\s+", replacement=" ", text="hello    world"
Output: { result: "hello world" }

explain_pattern

Get a plain English explanation of what a regex pattern does.

Input: pattern="^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$"
Output: { explanation: "Matches valid email addresses..." }

generate_pattern

Generate a regex pattern from a natural language description.

Input: description="Match any valid URL starting with http or https"
Output: { pattern: "^https?://[^\s/$.?#].[^\s]*$" }

split_string

Split a string using a regex pattern as the delimiter.

Input: pattern="\s*,\s*", text="apple, banana , orange"
Output: { result: ["apple", "banana", "orange"] }

validate_pattern

Validate if a regex pattern is syntactically correct.

Input: pattern="[a-z"
Output: { valid: false, error: "Unterminated character class" }

Features

• ✅ Test regex patterns instantly
• ✅ Extract and manipulate text with precision
• ✅ AI-powered pattern explanation
• ✅ Generate regex from natural language
• ✅ Full pattern validation
• ✅ Works seamlessly with Claude, Cursor, and Windsurf

License

Open source and free to use.

Built with AI by Craftpipe

Support: [email protected]