DEV Community

Profiterole
Profiterole

Posted on

I Made 29 MCP Developer Tools Free to Try — Here Are the 5 Worth Installing For

#ai #mcp #productivity #devtools

I maintain mcp-devutils, an MCP server with 45 developer utilities that run inside your AI assistant — Claude Desktop, Cursor, VS Code, wherever.

This week I switched to a trial model: 16 tools are free forever, and the 29 pro tools each get 3 free uses. No signup, no credit card. Just install and go.

Here are the 5 pro tools that made me build this thing in the first place.

1. json_diff — Compare API Responses Instantly

You're debugging why staging returns different data than production. Instead of pasting two JSON blobs into a browser diff tool:

"Compare these two API responses"

json_diff found 3 differences:
  - response.user.permissions: ["read"] → ["read", "write"]
  - response.metadata.version: "2.1" → "2.3"
  - response.metadata.cache_ttl: 300 → (missing)
Enter fullscreen mode Exit fullscreen mode

No copy-paste, no browser tabs. The diff runs inside your AI conversation.

2. sql_format — Readable Queries in Seconds

That 200-character one-liner from your ORM logs:

"Format this SQL: SELECT u.id,u.name,o.total FROM users u JOIN orders o ON u.id=o.user_id WHERE o.created_at>'2024-01-01' AND o.status='completed' GROUP BY u.id,u.name HAVING SUM(o.total)>100 ORDER BY SUM(o.total) DESC"

SELECT u.id,
       u.name,
       o.total
FROM   users u
JOIN   orders o ON u.id = o.user_id
WHERE  o.created_at > '2024-01-01'
  AND  o.status = 'completed'
GROUP  BY u.id, u.name
HAVING SUM(o.total) > 100
ORDER  BY SUM(o.total) DESC
Enter fullscreen mode Exit fullscreen mode

Reading raw ORM output is painful. This makes it scannable instantly.

3. jwt_create — Generate Test Tokens Without jwt.io

Building an auth flow? Instead of opening jwt.io and manually filling fields:

"Create a JWT with sub: user_123, role: admin, exp in 1 hour"

You get a signed token back immediately. Pair it with the free jwt_decode tool to verify what's inside. No browser, no bookmarks.

4. csv_json — Convert Data Formats In-Conversation

Got a CSV export you need as JSON for an API call?

"Convert this CSV to JSON: name,role,team\nAlice,eng,platform\nBob,pm,growth"

[
  {"name": "Alice", "role": "eng", "team": "platform"},
  {"name": "Bob", "role": "pm", "team": "growth"}
]
Enter fullscreen mode Exit fullscreen mode

Small thing. Saves 2 minutes every time.

5. aes_encrypt / aes_decrypt — Encrypt Sensitive Data Without a Script

Need to encrypt a config value or API key before committing?

"Encrypt this with AES: my-secret-api-key-123"

Returns the encrypted string + the key. Decrypt it later in the same conversation. No writing a one-off Node script, no googling OpenSSL flags.

How to install 

npm install -g mcp-devutils
Enter fullscreen mode Exit fullscreen mode

Add to your Claude Desktop config (claude_desktop_config.json):

{
  "mcpServers": {
    "devutils": {
      "command": "npx",
      "args": ["-y", "mcp-devutils"]
    }
  }
}
Enter fullscreen mode Exit fullscreen mode

16 tools are free forever (uuid, hash, base64, timestamps, JWT decode, regex, cron, and more).

29 pro tools get 3 free uses each — enough to know if they fit your workflow. If they do, it's a one-time $5 unlock for all of them. Permanently.

Try it →

Top comments (0)