An open standard for plugging AI apps into tools and data in one shared way.
MCP (Model Context Protocol) is a shared set of rules for connecting AI apps to outside tools and data. Anthropic released it as an open standard in November 2024. A protocol is simply an agreed way for programs to talk to each other.
Before, every AI app needed its own custom link to every service. With MCP, a service builds one MCP server, and any app that supports MCP can use it.
OpenAI adopted MCP in March 2025, and in December 2025 it was donated to a new foundation under the Linux Foundation. Easier connections bring a risk, though: plug in an untrustworthy server and the AI may follow bad instructions.
Think of it like this
Phones used to have different charger shapes, so borrowing a friend's charger often didn't work. Now one USB-C cable fits most devices. MCP is like USB-C for connecting AI apps to tools.
For example
In an app that supports MCP, you could connect your calendar and ask, "Sort out my plans for tomorrow."
Records about this
Source-checked moments from AI history.
The founding projects were MCP, goose and AGENTS.md, at a point when public MCP servers exceeded 10,000
A competitor accepting its rival's standard made it the de facto industry standard
Replaced the combinatorial explosion of N models times M data sources with a single open standard