The Model Context Protocol (MCP) is an open standard that gives AI agents one consistent way to connect to outside tools, files, and services. Introduced by Anthropic in late 2024 and adopted broadly since, it replaces dozens of custom integrations with a single shared interface.
Before MCP, connecting an AI assistant to each new system — a database here, a ticketing tool there — meant a bespoke integration every time, and none were reusable across apps. MCP fixes that the way a universal port did for laptops: build one server for your system, and any MCP-compatible assistant can use it. Write once, connect anywhere.
Three roles make it work. The host is the app a person uses. Inside it, an MCP client keeps a dedicated connection to each MCP server, and each server exposes tools, data, and prompt templates. Ask an agent to do something, and the model asks its client what is available, the client calls the relevant server, and results flow back — all in one shared format. Picture a marketing team running a server over their CMS: an assistant can then read live articles, check publish dates, and draft an update without anyone hand-coding that link for each tool they try.