Aug 12, 2025

What is MCP?

What is MCP?

What is MCP?

What is MCP in AI? Learn the Model Context Protocol, how clients and servers work, security basics, and a 10 minute Node and Python quick start with examples.

What is MCP in AI? Learn the Model Context Protocol, how clients and servers work, security basics, and a 10 minute Node and Python quick start with examples.

What is MCP in AI? Learn the Model Context Protocol, how clients and servers work, security basics, and a 10 minute Node and Python quick start with examples.

Read Time

10 min

This article was written by AI

Quick answer: Model Context Protocol is an open standard that lets AI assistants connect to your data and tools through MCP servers and clients so models can securely call tools and use live context. It matters because it standardizes integrations, improves answer relevance, and gives teams control over permissions and audit.

  • Standard connectors that work across clients and models

  • Fine grained permissions with consent and audit trails

  • Vendor neutral and open source, avoid lock in

  • Runs locally or remotely in your VPC

  • Faster time to value with reusable servers

Table of contents

  • Quick answer

  • MCP meaning vs other MCP acronyms

  • How the Model Context Protocol works

  • MCP security basics

  • Protocol at a glance

  • MCP quick start

  • MCP vs plugins and function calling

  • Enterprise guide

  • Ecosystem and integrations

  • FAQs

  • Resources and next steps

Quick answer: what is MCP?

Model Context Protocol lets an AI client dynamically discover tools and resources from MCP servers, request user approved scopes, and broker safe tool calls on behalf of a model. See the MCP quickstart or learn how to use MCP. For source material, visit the Model Context Protocol GitHub and the MCP architecture.

MCP meaning vs other MCP acronyms

This page covers the Model Context Protocol for AI

When people ask what is MCP, they often mean Model Context Protocol, a standard for connecting AI to tools and data. If you landed here from a search, you are in the right place. For the protocol details, see the Model Context Protocol overview.

Other MCPs you might be searching for

  • Microsoft Certified Professional

  • Microchannel plate detector used in imaging

  • Media Control Protocol in AV systems

  • Motor control protocols in robotics

How the Model Context Protocol works

Roles: MCP clients, MCP servers, and the model

  • MCP client: The AI application that hosts the model and user experience. It discovers servers, requests capabilities, and mediates permissions.

  • MCP server: A process that exposes tools, resources, and prompts over the protocol. Examples include Google Drive, GitHub, Git, Slack, Postgres, or a custom internal API.

  • Model: The LLM that plans and generates responses. The client lets it call tools safely through the server interface.

Flow: capability discovery, requests, and tool execution

  1. Discovery. The client starts or connects to a server and requests its capabilities.

  2. Listing. The server returns tools and resources with schemas and human readable descriptions.

  3. Consent. The client prompts the user for permissions and scopes. Approved scopes are stored per session or policy.

  4. Planning. The model proposes tool calls. The client enforces policy and can ask for confirmation.

  5. Execution. The client sends a tool call to the server. The server runs the action against the backing system.

  6. Streaming. The server streams progress or partial results when supported.

  7. Response. The client returns results to the model and the user. Errors include reasons and suggested fixes.

Suggested diagram: MCP client mediates model access to multiple MCP servers with consent and audit. Include arrows for listing, consent, call, and response. See MCP architecture and the protocol spec.

Security basics: permissions, auth, and data boundaries

  • Least privilege. Tools declare scopes. Clients ask users to grant only what is required.

  • Auth to backends. Servers hold credentials or use delegated identity. Rotate and scope secrets.

  • Data boundaries. Servers control what data is exposed. Clients isolate sessions and redact sensitive fields in logs.

  • User in the loop. Clients can require confirmation before any irreversible action.

  • Audit. Log tool calls, parameters, result metadata, and who approved them.

Permission prompt example: A GitHub MCP server requests scopes repo:read and issues:write. The client shows a prompt like: Grant GitHub server these scopes for this workspace? You can allow both, allow read only, or deny. If allowed, the client stores the grant and maps it to backend tokens with the same scopes.

MCP security basics

Security posture depends on the client and server you choose. Capabilities and consent UX vary by client, and enterprises must validate policy enforcement before rollout. Start with least privilege, explicit consent, and central audit logs. See MCP security and governance for deeper guidance.

  • Map each tool to a scope. Require consent for writes and destructive actions.

  • Use workload identity or short lived tokens for cloud resources.

  • Store secrets in a manager, rotate regularly, and limit egress.

  • Set retention on logs and mask credentials and PII in events.

Protocol at a glance: transport and message shapes

MCP uses structured JSON messages so clients can discover and call tools consistently. Common transports include stdio for local development, WebSocket for interactive remote servers, and HTTP for stateless operations.

Choosing transports

  • stdio: Easiest for local development, lowest overhead, no network required.

  • WebSocket: Best for remote interactive calls and streaming updates through an API gateway.

  • HTTP: Good for simple request response calls and serverless deployments.

Request: list tools

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list",
  "params": {}
}

Response: tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "tools": [
      {
        "name": "search_issues",
        "description": "Search issues by label and status",
        "inputSchema": {
          "type": "object",
          "properties": {
            "repo": { "type": "string" },
            "query": { "type": "string" }
          },
          "required": ["repo", "query"]
        },
        "scopes": ["repo:read"]
      }
    ]
  }
}

Request: call a tool

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "search_issues",
    "arguments": { "repo": "org/project", "query": "is:open label:bug" }
  }
}

Response: success

{
  "jsonrpc": "2.0",
  "id": 2,
  "result": {
    "content": [
      { "type": "text", "text": "Found 12 issues matching label bug" }
    ],
    "meta": { "elapsed_ms": 214 }
  }
}

Response: error with suggested fixes

{
  "jsonrpc": "2.0",
  "id": 2,
  "error": {
    "code": 400,
    "message": "Missing required argument: repo",
    "data": {
      "hint": "Provide repo like org/name",
      "suggested_fixes": [
        { "field": "repo", "example": "acme/api" }
      ]
    }
  }
}

See the living spec and schemas at protocol spec and example message schemas.

MCP quick start: build in 10 minutes

Tested environment: spec v1.0, Node SDK v0.6, Python SDK v0.3. Update versions as needed from the release notes.

Sticky mini nav: Prereqs • Step 1 • Step 2 • Step 3 • Troubleshooting

Prerequisites and setup

  • Node 18+ and Python 3.10+

  • A terminal and a text editor

  • An MCP capable client such as Claude Desktop

Quick links: MCP quickstart • Model Context Protocol GitHub

Step 1 Create a minimal MCP server in Node or Python

Language tabs Node default, Python below. Copy and paste. Keep your console free of extra prints so stdio stays clean.

Node

# Create a project
mkdir hello-mcp && cd hello-mcp
npm init -y
npm install @modelcontextprotocol/sdk

# hello.js
import { Server } from "@modelcontextprotocol/sdk/server";

const server = new Server({ name: "hello-mcp" });

// Expose a simple echo tool
server.tool({
  name: "echo",
  description: "Echo back the provided text",
  inputSchema: {
    type: "object",
    properties: { text: { type: "string" } },
    required: ["text"]
  },
  handler: async ({ text }) => {
    return { content: [{ type: "text", text }] };
  }
});

server.start(); // Defaults to stdio

Python

# Create a venv and install
python -m venv .venv
# macOS/Linux
source .venv/bin/activate
# Windows PowerShell
.venv\Scripts\Activate.ps1
pip install mcp

# hello.py
from mcp.server import Server, tool

server = Server(name="hello-mcp")

@tool()
def echo(text: str) -> str:
    """Echo back the provided text"""
    return text

if __name__ == "__main__":
    server.run()  # Defaults to stdio

Checklist: You should now have a folder with either hello.js or hello.py and no runtime errors when you run the file manually.

Step 2 Connect the server to a client such as Claude Desktop

  1. Open Claude Desktop settings.

  2. Add a new MCP server entry. Choose Command, then point to your script:

    • Node: node hello.js

    • Python: python hello.py

  3. Save. The client will start the process when needed and discover the echo tool.

Tip: If the UI differs, check the latest instructions in the How to use MCP guide.

Checklist: You should see echo listed under tools in the client.

Step 3 Run a test command and view logs

  1. Open a new chat and type: Call echo with text Hello from MCP.

  2. Approve the permission prompt.

  3. Confirm the model response includes the echoed text.

  4. Watch your terminal for server logs to verify requests and arguments.

Checklist: You should see a completed tool call with the echoed text in the chat and matching arguments in your terminal logs.

Troubleshooting your first run

  • Client cannot start the server. Check the command path and executable permissions. On macOS, allow Terminal or your shell to launch developer tools if prompted.

  • No tools listed. Ensure your server registers tools before start and writes only JSON to stdio. Move any debug prints to stderr.

  • Permission prompt missing. The client may be in auto mode. Enable confirmations in settings.

  • Stuck on connecting. Confirm Node or Python process runs and is not blocked by a firewall or shell policy.

  • Schema errors. Validate that inputSchema or function signatures match JSON types.

  • Windows venv. Use .venv\Scripts\Activate.ps1 in PowerShell or .venv\Scripts\activate.bat in cmd.

  • Common paths. On macOS with Apple Silicon, ensure you are using the right Python path, for example /opt/homebrew/bin/python3.

Remote example

To run an MCP server behind an API gateway with WebSocket, terminate TLS at the gateway, forward wss:// traffic to the server, and require an auth header like Authorization: Bearer <token>. Keep idle timeouts long enough for streaming.

Performance and cost notes

  • Use streaming when possible, it improves UX and may reduce token usage.

  • Batch simple calls to reduce round trips.

  • Set timeouts per tool and add idempotency keys for safe retries.

  • Detect chat loops by capping repeated error calls and surfacing fixes.

When to use MCP vs plugins, function calling, or connectors

Best fit checklist for MCP

  • You need one integration model across multiple AI clients and models.

  • You want strict permissions, consent, and audit trails for tool use.

  • You plan to run connectors locally or inside your VPC.

  • You prefer reusable open source servers over bespoke glue code.

  • You must avoid vendor lock in and preserve future portability.

Side by side comparison

Dimension         | MCP                           | Function calling only        | Legacy plugins            | LangChain/LlamaIndex connectors | Custom webhooks
-----------------|-------------------------------|------------------------------|---------------------------|----------------------------------|-----------------------------
Scope            | Protocol for tools and data   | Model call syntax only       | Host specific extension   | Framework specific adapters      | Anything you build
Security model   | Consent, scopes, audit        | App defined, ad hoc          | Varies by host            | Varies by framework              | You must design
Deployment       | Local or remote, VPC ready    | In app only                  | Host controlled           | In app or service                | Anywhere, no standard
Ecosystem        | Growing server directory      | None                         | Often deprecated          | Many, uneven quality             | None
Lock in          | Low, open spec                | Medium, model APIs           | High, host bound          | Medium, framework bound          | High, custom
Best use cases   | Enterprise safe tool access   | Simple parameter injection   | Legacy marketplaces       | Rapid prototyping                | One off integrations

Learn more in the MCP comparison guide, OpenAI function calling docs, LangChain connectors, and LlamaIndex connectors.

Not a fit

  • A single app that needs one or two simple functions without user consent or audit.

  • Prototype scripts that live entirely inside one model provider with no portability needs.

  • Integrations that must run inside a closed plugin marketplace with host defined APIs.

  • Data flows that cannot tolerate any broker or mediation layer.

Enterprise guide: deploying MCP securely

Local vs remote servers and network topologies

  • Local desktop. Great for prototyping with personal data and dev tools.

  • Remote in VPC. Run servers near data with private endpoints. Front them with an API gateway and WAF. Keep audit logs central.

  • Broker pattern. A relay starts per user servers on demand and proxies stdio or WebSocket.

  • Air gapped. Package servers and models on isolated hosts. Sync audit logs out through a controlled channel.

Auth options and least privilege patterns

  • API keys with scope and rotation in a secret manager.

  • OAuth 2.0 for user delegated access to SaaS.

  • Workload identity for cloud to cloud trust. Prefer short lived tokens.

  • Per tool scopes mapped to backend permissions. Deny by default.

References: OAuth 2.0, Zero trust architecture, and MCP security and governance.

Compliance and data residency considerations

  • Map tool scopes to data classifications. Prevent cross boundary reads.

  • Keep processing in region to meet GDPR or data localization rules.

  • Log who approved each call, inputs, result metadata, and retention policy.

  • Run periodic access reviews on high risk tools.

See ISO 27001 overview and SOC 2 guidance from the AICPA.

Monitoring, audit, and reliability

  • Metrics. Tool call rate, latency, error rate, approval rate, and time to consent.

  • Logs. Request IDs, tool names, arguments, redacted secrets, and result sizes.

  • Alerts. Repeated failures, unusual volumes, permission escalation attempts.

  • Resilience. Retries with idempotency keys, backoff, and circuit breakers per server.

MCP ecosystem and integrations you can use today

Official and community servers directory snapshot

See the curated MCP server directory for more.

Current MCP capable clients

As of Aug 2025

  • Claude Desktop

  • Headless CLI clients built by teams, often integrated into developer environments

Real world examples and ROI

  • Support triage. A model calls Slack and GitHub to route issues. Faster first response.

  • Developer flow. A model searches Git, runs tests, and opens PRs. Lower cycle time.

  • Ops dashboards. A model queries Postgres and annotates incidents. Better MTTR.

Roadmap, licensing, and governance

Spec versioning and compatibility guarantees

  • Semantic versioning for the spec and SDKs.

  • Minor releases add features without breaking existing servers or clients.

  • Major releases can change message shapes with clear migration guides.

  • Clients and servers negotiate supported versions during handshake.

Track changes in the release notes.

License, community, and how to contribute

  • Open source license. Review terms in the official repo.

  • Public discussions, issues, and proposals in the repo.

  • Contribute servers, clients, docs, and examples. Follow the contribution guidelines.

See GitHub organization and the repo license.

FAQs about MCP

What does MCP stand for?

Model Context Protocol. It is an open standard for connecting AI clients to tools and data through MCP servers with permissions and audit.

How is an MCP server different from a client?

A server exposes tools and resources. A client hosts the model and user experience and mediates discovery, consent, and tool calls.

Does MCP work offline or air gapped?

Yes. You can run clients and servers on isolated hosts and keep all data local. Sync audit logs out through a controlled channel.

What platforms support MCP?

Desktop clients like Claude Desktop, and headless clients you build. Servers run on macOS, Windows, and Linux.

Is MCP open source?

Yes. The spec and reference SDKs are open. Review the license in the official repo before production use.

Is MCP the same as function calling?

No. Function calling is a model API feature. MCP is a protocol that adds discovery, permissions, transport, and audit across tools and clients.

Does MCP replace plugins?

Often yes for new builds. It provides a portable, open approach where legacy plugins are host bound and often deprecated.

Can MCP run without internet?

Yes. Use local clients and servers communicating over stdio or a private network with no external calls.

Resources and next steps

  • Build now with the MCP quickstart, Build Servers, and Build Clients. Source: Model Context Protocol GitHub.

  • Learn concepts and architecture in depth: MCP architecture.

  • Join the community and stay updated: Community forum and announcements.

Summary: MCP gives models safe access to tools and data with a clear contract. Start by running the hello server, connect it in your client, and call your first tool. Then add scopes, logs, and deploy in your VPC.

Author:

Ultimate SEO Agent