MCP Servers

Claude Code is trapped on your machine until you fix it

Out of the box, Claude Code sees files on your disk. That's it. It can't check Slack, it can't read your PRs, it can't query your database.

MCP (Model Context Protocol) changes that. MCP servers are plugins that connect Claude Code to external services. Each one gives Claude Code the ability to read from or write to a tool you already use.

One conversation. Slack context, GitHub PRs, database queries, Figma specs. That's the pitch, and it actually delivers.

How it works

An MCP server is a small program that translates between Claude Code and an external API. Think of it like a USB hub: Claude Code is your laptop, and the MCP servers are the adapters for every service you already use.

Claude Code  →  MCP Server  →  External Service
   "read PR #42"  →  GitHub MCP  →  GitHub API
                   ←  PR diff, comments, status

Each server exposes tools that Claude Code can call: things like get_file_contents, list_pull_requests, create_pull_request. Claude Code discovers them automatically and uses them when your prompt calls for it. You don't have to do anything special.

Popular MCP servers

You don't need all of these. Most people start with one or two and add more as they feel the pull.

Setting one up

MCP servers live in a .mcp.json file at your project root. GitHub is the easiest one to start with:

{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "<your-token-here>"
      }
    }
  }
}

When Claude Code starts, it reads .mcp.json, launches the servers, discovers their tools. Now "show me my open PRs" just works.

For OAuth-based servers (Slack, Figma), there's an authorization flow instead of a static token. Each server's docs walk you through it.

A real setup: GitHub + Linear

Here's what a two-service config actually looks like:

{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "<your-github-token>"
      }
    },
    "linear": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-linear"],
      "env": {
        "LINEAR_API_KEY": "<your-linear-key>"
      }
    }
  }
}

With both connected, you can say "Find the Linear ticket for the auth bug, then check if there's a related PR on GitHub." Claude Code coordinates across both in a single response. This is where it gets genuinely fun.

Security: take this seriously

MCP servers have real access to your tools. They run as processes on your machine with the credentials you provide. Treat them like any API integration you'd wire into production.

Only connect servers you trust. Stick to official or well-maintained community servers.

Use scoped tokens. Don't hand over your admin token. Create a personal access token with minimum permissions. For GitHub, read-only repo and PR access covers most workflows.

Keep tokens out of version control. Never commit .mcp.json with real tokens. Use environment variables instead:

{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "$GITHUB_TOKEN"
      }
    }
  }
}

Using $GITHUB_TOKEN reads from your shell environment. The actual secret stays out of the file. Add .mcp.json to .gitignore and share a .mcp.json.example template with your team.

Getting started

Start with GitHub. It's the easiest to set up and the most immediately useful. Get it working before adding more.

Test with a simple query first. "List my open PRs" or "Show me recent Slack messages." If that works, the connection is solid.

Read the server docs. Five minutes reading specific token scopes and supported tools saves an hour of debugging. Every time.

Watch for rate limits. MCP servers make real API calls. "Search all 500 repos for security issues" will hit GitHub's rate limit fast. Be specific in your requests.