MCP server · Developer tools
Castov MCP server
by castovdev
Your AI can check busy ports, do subnet math, decode IDs and timestamps, and scan for leaked secrets, all on your own machine.
Castov is a small helper that gives your AI a set of everyday developer calculators and checkers. It runs entirely on your computer, so nothing about your code, logs, or keys leaves your machine. It is handy for anyone who works with ports, IP addresses, timestamps, IDs, or secret keys and wants exact answers instead of guesses.
What is an MCP server? The 30-second version
On its own, your AI can only chat with you. An MCP server is a small helper program that gives your AI a new skill or a connection to a tool, and here it connects your AI to Castov. Once connected, when you ask something like why port 3000 is busy, your AI calls Castov, Castov checks your machine, and the AI tells you the answer. Everything happens locally, so your data stays with you.
What this MCP server does
You ask your AI a question in plain words, like which process is using a port or what a subnet range looks like. Your AI passes that request to Castov, which runs the exact calculation or check on your computer. Castov sends the result back to your AI, and your AI explains it to you in the chat. No cloud calls, no accounts, no waiting. It is like having a tiny toolbox your AI can reach into when it needs a precise answer.
What you can do with it
- Find out which process is using a port and why it is busy
- Calculate the usable IP range, subnet mask, and host count for a CIDR block
- Decode the creation time hidden inside a UUIDv7, ULID, Snowflake, or MongoDB ObjectId
- Convert Unix timestamps to human dates and back
- Explain a cron schedule in plain English and show the next runs
- Generate strong random secrets for things like AUTH_SECRET or JWT_SECRET
- Scan a code snippet, git diff, or .env block for leaked API keys
Try asking your AI
- “Why is port 3000 busy and what service is using it?”
- “Calculate the usable IP range and subnet mask for 10.240.0.0/22”
- “When was this MongoDB ObjectId 507f1f77bcf86cd799439011 created?”
- “Generate a 256-bit secret I can use for AUTH_SECRET”
What it gives back to you
You get clear answers in the chat: a port number with the process name, a list of IP addresses and masks, a human-readable date, a fresh secret string, or a short report of any leaked keys found. For cron and timezone questions, it also shows the next few run times. Everything is shown as text you can read and copy.
Before you start
What you need
- Node.js 18 or newer installed on your computer
- The Claude desktop app, Cursor, Windsurf, or another AI tool that supports MCP servers
Good to know
It can read local files and environment variables when scanning for secrets, so only point it at things you are comfortable sharing with your AI session.
Install it with your AI
Add Castov MCP server to your AI, no technical skills needed
You don't install anything by hand. You copy one prompt, paste it into an AI that can work on your computer, and it checks, installs and connects the server for you, asking you when it needs something.
Sign in to get the install prompt
Members get a ready-made prompt that lets the Claude desktop app check Castov MCP server, install it and connect it for them, step by step. You don't need any technical skills: you copy, paste and answer a few questions. Your connected AI can also find and install any of the 4,609 MCP servers here for you.
Who it's for
Developers, DevOps engineers, and anyone who regularly deals with ports, IP ranges, timestamps, IDs, or secret keys.
