What is Model Context Protocol (MCP)? A Beginner-Friendly Guide for AI Developers | by Nishan Jain | Apr, 2025

Mannequin Context Protocol (MCP) is a brand new customary that makes it simple for AI fashions to attach with apps, instruments, and information sources securely. On this beginner-friendly information, we’ll clarify what MCP is, the way it works, and how one can arrange your personal MCP server.

Think about you’re constructing a journey app that helps customers guide flights utilizing an AI assistant.

At first, it sounds easy: you accumulate particulars like dates, locations, and passenger data, and ship them to the AI.
However right here’s the true drawback:

• The fee system expects one format.
• The seat choice system expects one other format.
• The luggage service expects one more format.

Now, you’re not simply sending info — you’re writing separate “translators” for each single instrument. Each time you connect with a brand new service, it’s important to work out their method of speaking to the AI.
And if one among them adjustments their format later? You must rewrite your code.

It turns into an enormous overhead:

• Extra customized code to take care of.
• Extra bugs to debug.
• Extra delays each time you add a brand new instrument.
• Tougher to scale your app throughout completely different companies.

And not using a widespread language, each new connection turns into a mini venture of its personal.
And for corporations, this implies larger prices, slower growth, and a much bigger likelihood of issues breaking.

For this reason the Mannequin Context Protocol (MCP) is so highly effective and helpful.

MCP provides everybody — the AI mannequin, the reserving app, the fee instrument, the bags system — one easy, shared method to change context.
No extra guessing. No extra messy translations. Simply clear, dependable connections. It standardizes how functions present context to LLMs.

Briefly, MCP is an Integration Drawback Solver.

MCP helps you construct brokers and sophisticated workflows on high of LLMs. LLMs continuously must combine with information and instruments, and MCP supplies:

• A rising record of pre-built integrations that your LLM can straight plug into
• The flexibleness to modify between LLM suppliers and distributors
• Greatest practices for securing your information inside your infrastructure

At its core, MCP follows a client-server structure the place a bunch utility can connect with a number of servers.

In Mannequin Context Protocol (MCP), there are three fundamental components:

Host

The primary setting the place every thing runs, like a desktop app (Claude Desktop), browser, IDE, or different platforms. It manages each shoppers and servers, serving to them discover and discuss to one another.

The Host acts like a bridge:

• It connects shoppers and servers inside the identical app or setting.
• It manages how communication occurs.
• It ensures safety, discovery, and clean messaging.

Consumer

Normally, an AI utility (like a chatbot or agent). It requests context: paperwork, instruments, prompts, and so on.

Server

An MCP server connects to a instrument or information supply (like a file app, database, or chat app) and exposes particular capabilities that an AI app can use, similar to looking out recordsdata, fetching mentions, or updating standing.

MCP servers present three sorts of issues:

• Prompts: Pre-made templates that customers can set off.
• Sources: Structured information like recordsdata, commits, or database rows.
• Instruments: Actions the AI can carry out, like calling APIs or modifying recordsdata.

All of the communication between shopper and server follows:

• Protocol Layer: Message codecs (requests, responses, notifications) utilizing JSON-RPC 2.0.
• Transport Layer: defines how the messages journey, utilizing issues like stdio (customary enter/output for native communication) or HTTP+SSE (for distant communication).

Set up the MCP Python SDK

brew set up uv #set up uv(this command works for Mac)
# Create a brand new venture
uv init mcp-server-demo
cd mcp-server-demo
# Set up mcp as dependency
uv add "mcp[cli]"

Create a Primary MCP Server

Create a file known as server.py:

from mcp.server.fastmcp import FastMCP
# Step 1: Create an MCP server
mcp = FastMCP("Demo Server")
# Step 2: Add a easy instrument
@mcp.instrument()
def add(a: int, b: int) -> int:
"""Provides two numbers."""
return a + b
# Step 3: Add a useful resource
@mcp.useful resource("greeting://{title}")
def get_greeting(title: str) -> dict:
"""Returns a greeting message."""
return {"message": f"Hiya, {title}!"}
# Step 4: Run the server
if __name__ == "__main__":
mcp.serve()

mcp set up server.py

This can begin your MCP server domestically, exposing:

• A instrument (add) that provides two numbers.
• A useful resource (greeting) that generates a greeting message.

While you run the server command, Claude Desktop ought to mechanically detect and add your MCP server.
For those who don’t see it seem instantly, strive restarting the Claude Desktop app. You may verify your Demo Server within the MCP server record.

While you run the MCP server command, Claude Desktop mechanically updates its inside claude_desktop_config.json file by including an entry like this:

"Demo Server": {
"command": "uv",
"args": [
"run",
"--with",
"mcp[cli]",
"mcp",
"run",
"/Customers/nishanjain/Desktop/mcp-server-demo/server.py"
]
}

Whereas Mannequin Context Protocol (MCP) makes connecting AI fashions to instruments and information a lot simpler, it additionally opens up new safety dangers.
As a result of AI fashions can now use instruments (not simply learn information), securing these connections turns into crucial.

Listed here are the most important safety dangers you have to be conscious of:

• Immediate Injection:
  Intelligent prompts can trick the AI into misusing instruments (e.g., leaking delicate recordsdata).
• Device Description Poisoning:
  If a server describes its instruments in a deceptive method, the AI may carry out unsafe actions with out realizing it.
• Malicious or Compromised Servers:
  Not all MCP servers could also be reliable. A rogue server can manipulate instrument outputs or leak information.
• Lack of Authentication:
  With out verifying shoppers and servers correctly, unauthorized instruments could possibly be related, or non-public information could possibly be uncovered.
• Credential Leaks and Knowledge Exfiltration:
  Delicate info accessed by the AI (like API keys or database data) might by chance be leaked via instrument outputs.

To construct safer MCP-based techniques, comply with these rules:

• Robust Authentication:
  All the time confirm the id of MCP shoppers and servers earlier than permitting entry.
• Scoped Authorization:
  Restrict what every instrument or shopper is allowed to do — comply with the precept of least privilege.
• Enter Validation and Output Sanitization:
  Deal with all inputs as probably harmful and strictly validate them; sanitize outputs earlier than returning them to the AI.

Mannequin Context Protocol (MCP) makes it a lot simpler to attach AI fashions with real-world instruments, apps, and information — all via a clear, standardized method.
As an alternative of constructing customized integrations for each app, builders can now expose capabilities rapidly utilizing MCP servers.

Nevertheless, with this new energy additionally comes duty. Since MCP permits fashions to learn and take motion, it’s necessary to consider safety, like verifying servers, controlling instrument permissions, and validating inputs, to forestall potential dangers.

With good practices, MCP can unlock wonderful prospects safely and securely.

https://writer.com/engineering/mcp-security-considerations/