Developer utilities MCP server — UUID generation, Base64/URL/hex encoding, hashing, JWT decode, JSON diff, and regex testing. All free, zero config, no API keys.

The free alternative to paid devtools MCP servers. 6 tools, ~3,300 tokens total schema cost (grade A).

Install

npx dev-utils-mcp

That's it. No config files, no API keys, no accounts.

Tools

`generate` — UUID, hex, and nanoid generation

"Generate 5 UUIDs"
"Give me a 32-char hex string"
"Generate 10 nanoid-style IDs"

`encode_decode` — Base64, URL, HTML, hex

"Base64 encode this API key"
"URL decode this query string"
"HTML encode this snippet for embedding"

`hash` — MD5, SHA-1, SHA-256, SHA-512

"Hash this string with SHA-256"
"Give me MD5 and SHA-512 of this text"

`jwt_decode` — Decode JWT tokens

"Decode this JWT token and tell me if it's expired"
"What's in the payload of this JWT?"

Shows header, payload, expiration status, and time remaining. No signature verification (read-only decode).

`json_utils` — Format, minify, validate, diff, extract

"Format this JSON"
"Diff these two JSON configs and show what changed"
"Validate this JSON"
"Extract the value at data.users[0].name"

`regex_test` — Test regex patterns

"Test this regex against my log file"
"Show all matches and capture groups for this pattern"

Returns all matches with indices, groups, and named groups.

Configuration

Claude Desktop / Claude Code

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

Cursor

Add to .cursor/mcp.json:

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

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

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

Why This Exists

Every developer uses UUID generators, Base64 encoders, JWT decoders, and JSON formatters daily. Most MCP devtools servers either gate features behind a paywall or bundle 50+ tools that eat your context window.

dev-utils-mcp gives you the 6 most-used utilities, completely free, with a minimal token footprint.