Complete Guide to Installing Your First MCP Server on Claude Desktop (2026)

What MCP servers are and why install one

Out of the box, Claude Desktop knows only what's in its training data. It can't read your files, check your calendar, query your database, or update your Notion page. An MCP server is a small program that runs on your computer and gives Claude a specific capability — access to your filesystem, a connection to GitHub, the ability to query Postgres, whatever. Once you install one, that capability shows up in Claude's toolbelt: ask a question that needs it, and Claude uses it.

The whole point of the Model Context Protocol is that every server speaks the same language. That means once you understand how to install one, you understand how to install all of them. The Filesystem MCP and the GitHub MCP and the Slack MCP all follow the same install pattern with different arguments — a fact that turns a scary-looking ecosystem into a very small learning curve.

If you want the broader picture of what's available, our servers directory catalogues 104 published servers across 10 categories. This guide is about the install mechanics; that page is about picking what to install.

What you need before starting

• Claude Desktop installed and logged in (free or paid tier works for local MCP servers)
• Latest version — check Settings → About and update if needed; older versions have different config formats
• A text editor — VS Code, Sublime, Notepad++, or even the default Notepad/TextEdit will do
• 15 minutes — the actual install takes 3–5, the rest is testing and verifying

You do not need Node.js installed manually — Claude Desktop now ships with a bundled Node.js runtime for MCP servers. You do not need Docker for most first-time servers. You do not need to know JavaScript, Python, or any other programming language.

The two installation methods

As of mid-2026, Claude Desktop supports two ways to install a local MCP server, plus a third method (Custom Connectors) for hosted/remote servers on paid plans. Pick the method that fits both your comfort level and the server you're trying to install.

Both methods produce the same result: Claude Desktop knows about a new tool it can use. Use Method 1 whenever the server is available as an extension (check its page in the directory); use Method 2 for everything else.

1Method 1: Desktop Extensions (one-click)

Desktop Extensions are Anthropic's answer to the "install five things, edit two files, hope it works" problem. An extension is a single file (usually .dxt or .mcpb) that contains the server code plus a manifest telling Claude Desktop everything it needs to know. Install feels exactly like adding a browser extension.

1. Find the extension file for the server you want. Most published servers link to their extension file from their homepage. The server pages in our directory link out to the extension file when one exists.
2. Open Claude Desktop → Settings → Extensions. This tab appeared in the Settings sidebar in the Desktop Extensions launch update.
3. Drag the .dxt file into the Extensions panel (or click "Install Extension" and browse to it).
4. Review the permissions. Claude Desktop shows what the server will access. Read this — it's the equivalent of reading a browser extension's permission prompt. If it wants file access, note which paths.
5. Click Install and restart Claude Desktop if prompted. That's it. The tool is now available in any conversation.

2Method 2: Manual JSON config (Filesystem MCP walkthrough)

For servers that aren't packaged as extensions — or when you want fine control over configuration — you edit claude_desktop_config.json directly. This is the universal method: every MCP server works this way, whether or not it also has an extension.

We'll walk through installing the Filesystem MCP as your first server. It's the recommended starter because it needs no API keys, no OAuth, no external accounts — just a folder path.

Step 1 — Open the config file

The easiest way to find it: Settings → Developer → Edit Config in Claude Desktop. That opens the file in your default text editor, no navigating required. The file lives at:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

If the file doesn't exist yet, Claude creates it empty ({}) the first time you open it. That's fine — we're about to add content.

Step 2 — Paste the config

Replace the file's contents (which should just be {} if it's new) with:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "/Users/YOUR-USERNAME/Documents/claude-scratch"
      ]
    }
  }
}

Two edits to make it yours:

• Replace YOUR-USERNAME with your actual username
• Replace the folder path with a scratch folder you create first — don't point it at your Documents folder on day one. Make a new folder called claude-scratch, put a few test files in it, and use that path.

On Windows, paths use backslashes and need to be escaped: "C:\\Users\\YourName\\Documents\\claude-scratch". The double backslashes are required — single backslashes will break the JSON.

Step 3 — Save and restart

Save the file. Fully quit Claude Desktop (not just close the window — on macOS use Cmd+Q; on Windows use the system tray). Reopen it. MCP servers load only at startup, so this restart is non-optional.

Verifying it works

After restart, look at the bottom of the Claude Desktop chat window. You should see a small tools icon (a hammer or plug). Click it — you'll see the Filesystem MCP's available tools listed: read_file, write_file, list_directory, and a few others. If you see them, the server loaded successfully.

Now test it with a real task. Type into Claude:

List all the files in my claude-scratch folder and tell me
what each one appears to contain.

Claude should ask permission to use the filesystem tool. Approve it. It'll list the folder contents and describe what's inside. Congratulations — you have a working MCP server.

Common errors and fixes

If you don't see the tools icon or Claude says the server isn't available, the problem is almost always one of these four things. Check them in order — each takes 30 seconds to verify.

• You didn't fully restart Claude Desktop. Closing the window isn't enough; MCP config only reloads on a full quit-and-reopen. On macOS: Cmd+Q. On Windows: right-click the tray icon → Quit.
• Your JSON has a syntax error. Missing commas and trailing commas are the top culprits, followed by unescaped Windows paths. Paste your config into jsonlint.com before saving — it'll pinpoint the exact character that's wrong.
• Claude Desktop launched with a minimal PATH. Short names like npx often work in your terminal but fail when Claude Desktop spawns processes, because Claude launches with a stripped-down environment. Fix: use the full absolute path to the executable (/opt/homebrew/bin/npx on macOS with Homebrew, or the full path from which npx).
• You edited the wrong file. Some editors save to a copy in another directory, and there's exactly one file Claude Desktop reads: claude_desktop_config.json. Verify by using Settings → Developer → Edit Config from inside Claude itself — that always opens the correct file.

If none of those fix it, Claude Desktop has a logs panel (Settings → Developer → Show Logs) that will show the actual error message from the server. Copy the error and search it — someone else has almost certainly hit the same thing.

What server to install next

Once Filesystem is working, the natural progression depends on what you want Claude to do:

• Want Claude to read your code repos? Install the GitHub MCP. Requires a Personal Access Token — walk through the setup in our GitHub MCP OAuth setup guide.
• Want Claude to query a database? Try the Postgres MCP or SQLite MCP — our safe read-only databases guide covers the safety patterns.
• Want Claude to work with your notes? The Notion MCP or Google Drive MCP are the popular picks.
• Want to see what else exists? Browse the full 104-server directory by category.

Frequently asked questions