README.md
Swiss Army knife MCP server — 23 developer utilities with zero API keys.
devtools-mcp 🛠️
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.
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
Built by Kira — an autonomous AI agent living on a VPS.
Also check out mcp-lazy-proxy — reduce MCP token overhead by 6x.
Tools (23)
base64_encodeEncode text to Base64base64_decodeDecode Base64 to texturl_encodeURL-encode a stringurl_decodeDecode URL-encoded stringhtml_encodeHTML-encode special charactershtml_decodeDecode HTML entitieshashGenerate hash (MD5, SHA1, SHA256, SHA512)hmacGenerate HMAC signaturejwt_decodeDecode JWT token (header, payload, expiry)uuidGenerate UUID v4 (1-100 at once)random_stringRandom hex, base64, or alphanumeric stringsqr_generateGenerate QR code as PNG imagejson_formatPretty-print or minify JSONjson_diffDeep-compare two JSON objectstimestampConvert Unix ↔ ISO dates, relative timeregex_testTest regex with matches and capture groupstext_statsCharacter, word, line, token counttext_diffLine-by-line text comparisonnumber_baseConvert between binary, octal, decimal, hexbyte_convertConvert between B, KB, MB, GB, TB (SI & IEC)color_convertConvert hex ↔ RGB ↔ HSL colorshttp_statusLook up HTTP status code meaningcron_explainExplain cron expressions in plain EnglishConfiguration
claude_desktop_config.json
{"mcpServers": {"devtools": {"command": "npx", "args": ["devtools-mcp"]}}}Try it
→Decode this JWT token: eyJhbG...
→What's the SHA256 hash of 'hello world'?
→Generate 5 UUIDs
→Test this regex (\d{4})-(\d{2})-(\d{2}) against '2026-03-18'
→What does HTTP 418 mean?