What is an MCP client?

An MCP client is the AI app side of a connection to an MCP server, such as Claude, Claude Code or VS Code.

An MCP client is the part of an AI app that keeps one connection open to one MCP server. The app that contains it, such as Claude Desktop or VS Code, is called the host.

Also called MCP clients, MCP host, MCP host application, mcp client app, client for MCP.

MCP has three roles. The host is the AI app you use. The client is a piece inside the host that talks to one server.

The server is the program that supplies the tools and data.

If you connect an app to three servers, it runs three clients, one per server. In everyday talk people call the whole app "the MCP client", and that is fine for choosing one to use. The split matters when you read the spec or build an app.

The MCP docs give Visual Studio Code as a host. When it connects to the Sentry server and to a local filesystem server, it creates one client for each.

An MCP client is the part of an AI app that connects to an MCP server and fetches its tools and data. Claude Desktop and Claude Code are hosts that create clients like this for you, one per server. When you add a server in one of these apps, you are setting up a client without having to build one.

The one thing to know first: which servers you can use depends on what your app supports. Local servers run on your computer and need an app that can start them. Hosted servers need an app that can connect over the internet and handle sign-in.

Clients can also offer features back to servers. One example is elicitation, which lets a server ask you for missing information in the middle of a task. See our pages for Claude Desktop, Claude Code, Cursor, Windsurf and ChatGPT.

Good for

Users choosing which AI app to use with MCP servers
Developers adding MCP support to their own app
Readers confused by host, client and server
Admins deciding which apps may reach company data

Comparison

When you pick something to use, pick a host. The client is built into it.

Option	What it is	Example	How many
HostThis page	The AI app	Claude Desktop	One per app
Client	Link to one server	Inside the host	One per server
Server	Supplies tools and data	Notion MCP	As many as you add

Questions

What is an MCP client?

The part of an AI app that holds a connection to one MCP server. It asks the server what it offers, sends tool calls and passes results back to the app.

What is the difference between an MCP host and an MCP client?

The host is the AI app, like Claude Desktop. The client is a component inside it that connects to one server. A host with three servers has three clients.

Which apps are MCP clients?

Any AI app that connects to MCP servers is a host with clients inside it. The MCP docs name Claude.ai and Visual Studio Code as examples. We keep pages for Claude Desktop, Claude Code, Cursor, Windsurf and ChatGPT.

Do I need to build an MCP client?

Only if you are making your own AI app. If you use Claude, ChatGPT or Cursor, the client is already built in and you just add servers.

What does an MCP client do?

It connects to a server, learns what tools and data the server offers, and makes calls for the app. It can also let the server ask you questions, through a feature called elicitation.

Can one MCP client connect to many servers?

Not exactly. Each client connects to one server, but the host app creates as many clients as it needs. You can connect one app to many servers.

Can any client use any MCP server?

Not always. Local servers need an app that can start them on your computer, and hosted servers need an app that can reach them over the internet. Check the server page for the apps it works in.

How do I test a client or server without an AI app?

Use the MCP Inspector, which acts as a simple client for any server.

Sources

Docs, issue trackers and discussions this page is built from.

Show all 2

Understanding MCP clients · modelcontextprotocol.io
Architecture overview · modelcontextprotocol.io