What Is an MCP Server? A Plain-English Guide (2026)
An MCP server is a small program that gives an AI assistant a set of tools — read a database, send a message, call an API — over one open protocol. Here is the whole idea in five minutes.
An MCP server is a small program that exposes a set of tools to an AI client — Claude, Cursor, and others — over the Model Context Protocol, an open standard from Anthropic. When you connect one, the assistant can do real things: query a database, open a GitHub PR, search the web, send a Slack message.
Why it exists
Before MCP, every AI app wired up integrations its own way. MCP is the "USB-C for AI tools": build a server once, and any MCP-aware client can use it. That is why a catalog like Unyly can list 51,000+ of them — they all speak the same protocol.
The two kinds
- Local (stdio) servers run on your machine, usually launched via
npxoruvx. Great for filesystem, local databases, dev tools. - Remote (HTTP) servers run in the cloud and connect over a URL, often with OAuth. Better for hosted APIs and shared team access.
How you use one
- Find a server for the job (e.g. a GitHub MCP).
- Install it into your client — a command, a config entry, or one click.
- Restart the client; its tools appear.
- Ask the assistant naturally — it decides when to call the tool.
The catch, and the shortcut
The friction is step 2 — hand-editing JSON per client. Unyly's Install button writes the config for the client you pick and keeps servers updatable. Browse the catalog to see what is possible.