For users, MCP collapses integration to configuration: adding a server to Claude Code, Cursor, ChatGPT, or any compatible client is a line of config, after which the server's tools appear in the conversation like native abilities.
For products, it inverts the usual architecture. Instead of building an app that embeds an AI, you build a server that plugs into the AI surface people already use. The user keeps their client, their model choice, and their subscription; the server supplies the domain: its data, its actions, its rules.
The protocol was introduced by Anthropic as an open standard in November 2024 and has since been adopted across many AI clients and developer tools. A connection has two roles: the server, which exposes tools, resources and prompts, and the client inside the AI application, which discovers them and passes the model's calls through. Servers run locally over standard input and output, or remotely over HTTP, usually with OAuth sign-in. Because the protocol is shared, a server written once reaches every client that implements it.