What are MCP servers and why should I use them?

The Model Context Protocol (MCP) is an open standard (open-sourced by Anthropic) for connecting AI assistants to external tools and data sources. An MCP server exposes a specific resource — GitHub, Linear, Sentry, your Postgres database, your Magento DB, your design system — through a standardised interface that Claude Code can call.

You wire MCP servers in .claude/mcp.json. Once wired, Claude Code can read your GitHub issues, query your Magento DB, fetch Sentry stack traces, file Linear tickets — all without you copy-pasting context into chat. Crucially, your API keys live in MCP server config, not in your prompts — so they don’t leak into your conversation logs. Anthropic + the community ship 100+ official MCP servers; building your own is a 50-line Node script.