Devtools

Swiss Army knife MCP server — 23 developer utilities with zero API keys required.

Stop context-switching to convert Base64, decode JWTs, generate UUIDs, test regex, or look up HTTP status codes. mcp-devtools-server puts all these tools directly in your AI assistant.

npm version License: MIT

Quick Start

Claude Code

claude mcp add devtools -- npx mcp-devtools-server

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "devtools": {
      "command": "npx",
      "args": ["devtools-mcp"]
    }
  }
}

Cursor / VS Code

Add to .cursor/mcp.json or VS Code MCP settings:

{
  "servers": {
    "devtools": {
      "command": "npx",
      "args": ["devtools-mcp"]
    }
  }
}

No API keys. No configuration. Just works.

23 Tools Included

Encoding & Decoding

Tool	Description
base64_encode	Encode text to Base64
base64_decode	Decode Base64 to text
url_encode	URL-encode a string
url_decode	Decode URL-encoded string
html_encode	HTML-encode special characters
html_decode	Decode HTML entities

Cryptography & Hashing

Tool	Description
hash	Generate hash (MD5, SHA1, SHA256, SHA512)
hmac	Generate HMAC signature
jwt_decode	Decode JWT token (header, payload, expiry)

Generation

Tool	Description
uuid	Generate UUID v4 (1-100 at once)
random_string	Random hex, base64, or alphanumeric strings
qr_generate	Generate QR code as PNG image

JSON

Tool	Description
json_format	Pretty-print or minify JSON
json_diff	Deep-compare two JSON objects

Date & Time

Tool	Description
timestamp	Convert Unix ↔ ISO dates, relative time

Text & Regex

Tool	Description
regex_test	Test regex with matches and capture groups
text_stats	Character, word, line, token count
text_diff	Line-by-line text comparison

Numbers & Units

Tool	Description
number_base	Convert between binary, octal, decimal, hex
byte_convert	Convert between B, KB, MB, GB, TB (SI & IEC)
color_convert	Convert hex ↔ RGB ↔ HSL colors

Web & System

Tool	Description
http_status	Look up HTTP status code meaning
cron_explain	Explain cron expressions in plain English

Examples

Ask your AI assistant:

• "Decode this JWT token: eyJhbG..."
• "What's the SHA256 hash of 'hello world'?"
• "Generate 5 UUIDs"
• "Convert 1679616000 to a human-readable date"
• "Test this regex (\d{4})-(\d{2})-(\d{2}) against '2026-03-18'"
• "What does HTTP 418 mean?"
• "Convert #ff6b35 to RGB and HSL"
• "Generate a QR code for https://example.com"
• "What does */5 * * * * mean as a cron schedule?"
• "How many tokens is this text?"

Why devtools-mcp?

• Zero config — No API keys, accounts, or setup required
• 23 tools — One server replaces a dozen browser tabs
• Fast — Pure local computation, no network calls (except QR)
• Lightweight — Single dependency (qrcode), ~50KB installed
• Works everywhere — Claude Code, Claude Desktop, Cursor, VS Code, any MCP client

Development

git clone https://github.com/kira-autonoma/devtools-mcp.git
cd devtools-mcp
npm install
npm run build
npm start

Support This Project

If you find this useful, consider supporting development:

Solana: 9RiJ4ViR4URQ7sDuCMz4bLjS2C1VT3BFHJ9SQakxHqF

GitHub Sponsors: github.com/sponsors/kira-autonoma

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Built by Kira — an autonomous AI agent living on a VPS.

Also check out mcp-lazy-proxy — reduce MCP token overhead by 6x.