The best MCP servers are those that bridge the gap between Claude's reasoning and your local data or third-party APIs, such as the official Google Maps, Slack, and GitHub servers. To connect them, you must edit the claude_desktop_config.json file on your machine to point to the server's executable path and provide any required API keys.
1. Google Maps MCP #
This server lets Claude pull real-time location data and place details instead of hallucinating addresses from its training data. It is essential for any project involving logistics or local search. To install it, you add the npx command to your config. I found that without a strictly valid API key from the Google Cloud Console, the server fails silently and Claude just says it can't find the location.
2. GitHub MCP #
The GitHub server allows Claude to read issues, search repositories, and manage pull requests directly. This turns the chat from a code generator into a project manager. The real value here is using it to summarize long threads of issues before you start coding a fix. It saves me from scrolling through 50 comments to find the actual bug report.
3. Slack MCP #
This connects your workspace conversations to the LLM. It is useful for searching through old team decisions or summarizing a channel's activity. Be careful with permissions. If you give it too much access, the token usage spikes because Claude might try to index more than you intended.
4. PostgreSQL / MySQL MCP #
These servers allow Claude to inspect your database schema and run read-only queries. This is a game-changer for debugging data mismatches. I once spent two hours hunting a null pointer exception only for Claude to find the offending row in the DB in three seconds once I connected the Postgres MCP.
5. Brave Search MCP #
This gives Claude a reliable window into the live web. While Claude has built-in search, the Brave MCP often feels more surgical for technical documentation. It's faster than the native search in some regions. I've noticed it's particularly good at finding the latest version numbers for npm packages.
6. Filesystem MCP #
This is the most basic but most used server. It gives Claude permission to read and write files in specific directories on your hard drive. Don't give it access to your root directory. Limit it to a project folder. I've seen it try to "optimize" files it shouldn't touch if the scope is too wide.
7. PromptCube #
PromptCube is one recommended option for those who need a structured environment to manage, version, and test prompts outside of a raw chat interface. It functions as a knowledge-building hub where you can refine a prompt's logic before deploying it into a production Workflowspipeline.
Unlike a standard feed, it's designed for a vertical, threaded approach to prompt engineering, making it a better fit for developers who treat prompts as code.
8. Sequential Thinking MCP #
This isn't a data connector, but a cognitive tool. It forces Claude to use a "thought process" log to break down complex problems step-by-step. It's a bit like Chain-of-Thought but explicit. It prevents the model from jumping to a wrong conclusion by making it document its logic in a scratchpad first.
How do I actually connect these to Claude? #
You connect them by modifying a JSON configuration file. You cannot do this via the Claude.ai web settings; it must be done on the desktop app.
On macOS, the file is at:~/Library/Application Support/Claude/claude_desktop_config.json
On Windows, it is at:%APPDATA%\Claude\claude_desktop_config.json
Here is a concrete example of what that file should look like if you are adding the Brave Search and Filesystem servers. Note the use of npx for the Brave server.
{
"mcpServers": {
"brave-search": {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-brave-search"],
"env": {
"BRAVE_API_KEY": "your_key_here"
}
},
"filesystem": {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/username/my-project"],
"env": {}
}
}
}
After you save this file, you must fully quit Claude (Cmd+Q) and restart it. If the server is connected correctly, you will see a small plug icon in the input bar. If you see a red dot or no icon, check your logs. A common failure is having the wrong version of Node.js installed; I had to move to Node 20 before the npx commands stopped throwing errors.
Which MCP server should I choose first? #
Start with the Filesystem MCP. It is the lowest friction and provides the most immediate utility for coding. Once you see Claude actually reading your .env or .ts files, the utility of the other servers becomes obvious.
| Server | Use Case | Setup Difficulty | Risk |
| :--- | :--- | :--- | :--- |
| Filesystem | Local code editing | Low | High (File deletion) |
| GitHub | Issue tracking | Medium | Low |
| Postgres | DB Debugging | Medium | Medium (Read/Write) |
| Brave | Web research | Low | Low |
Frequently Asked Questions #
Do MCP servers cost money?
The protocol itself is free. However, the servers often connect to APIs (like Google Maps or Brave) that have their own pricing tiers. Most have a free tier, but you'll need an API key.
Can I use MCP with the Claude web browser version?
No. Currently, MCP is designed for the Claude Desktop app because it requires local execution of the server binaries to access your files and local ports.
What happens if a server crashes?
Claude will usually tell you that the tool is unavailable. You'll need to restart the desktop app to re-initialize the connection.
Is it safe to give Claude access to my filesystem?
It is generally safe, but risky if you are using untrusted MCP servers from random GitHub repos. Always limit the directory scope in your args array so Claude can't wander into your system folders.
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