How to use MCP server tools in the Claude App?

What is MCP?

MCP stands for Model Context Protocol. It is an open-source project run by Anthropic and is open to contributions from the entire community. It lets Claude and other AI models directly interact with your tools and data. Instead of copying and pasting between applications, the AI can:

• Search the web and summarize the findings
• Read and write files on your computer
• Access your GitHub repositories
• Pull data from Google Drive
• Search through Slack messages
• Interact with maps

...and much much more!

This brief tutorial assumes that:

• You use Windows OS
• You have the Claude Desktop App installed.
• You have NodeJS, including npx and node installed

So what do you need to do?

• Create or update claude_desktop_config.json in the folder where your Claude is installed.

Mine is here c:\Users\<username>\AppData\Roaming\Claude

but look for your <username>

• Add the configuration depending on which MCP server tools you want to use.

You will find all the information here:

https://github.com/modelcontextprotocol/servers

Here is my file (of course, without the user name and the Brave API key):

WARNING: I am using node.exe as there is an issue with npx when it comes to MCP!

{
  "mcpServers": {
    "brave-search": {
      "command": "C:\\Program Files\\nodejs\\node.exe",
      "args": [
        "c:\\Users\\<username>\\AppData\\Roaming\\npm\\node_modules\\@modelcontextprotocol\\server-brave-search\\dist\\index.js"
      ],
      "env": {
        "BRAVE_API_KEY": "<brave_api_key>"
      }
    },
    "filesystem": {
      "command": "C:\\Program Files\\nodejs\\node.exe",
      "args": [
        "c:\\Users\\<username>\\AppData\\Roaming\\npm\\node_modules\\@modelcontextprotocol\\server-filesystem\\dist\\index.js",
        "c:\\Users\\<username>\\myfolder"
      ]
    }
  }
}        

The docs assume you use npx and I am pretty sure they will fix it!

{
  "mcpServers": {
    "brave-search": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-brave-search"
      ],
      "env": {
        "BRAVE_API_KEY": "YOUR_API_KEY_HERE"
      }
    }
  }
}        

• Install the relevant MCP packages. In my case it's Brave Search and Filesystem.

npm install -g @modelcontextprotocol/server-brave-search 
npm install -g @modelcontextprotocol/server-filesystem         

• If you proceeded correctly and restart Claude, the MCP server tools should be indicated in the Claude Desktop App:

It even shows you what MCP tools are specifically available to you :)

• Give it a try using a prompt of your choice:

In my example, I am looking for the latest Champions League results and goal scorers, and I want the results to be dumped in the file in the predefined folder.

Claude communicates with the MCP Server, gets information on the tools (capabilities), runs the given query, and the MCP Server does the job: searching the web or database, managing local files, or carrying out other actions.

There are some predefined servers:

You can create a custom one yourself!

So the flow goes like per this sequence diagram

(from https://modelcontextprotocol.io/quickstart)

So, what does it look like in the App? Claude gets the results, and the scorers, and then it dumps them into a file:

And my sample output file looks like this:

This feature opens many possibilities to enhance Claude's default capabilities.

Of course, this is a beta version, so you should expect some glitches:

• The non-working npx call of the MCP servers (as of now - November 27th, 2024)
• There are annoying confirmation request windows every time an MCP tool is called:

• For some reason, Claude tries to use the Claude App folder to save the file (but it realises it can't, so it jumps to the location I defined in my JSON config.

But now, I can use Claude as a search engine, too. I will invent new, cunning ways of connecting the MCP tools!

And I am pretty sure I will create my own MCP Server at some point :)

Happy experimenting! Contact me if you have any remarks or questions!