What Is the Model Context Protocol (MCP)? Anthropic's Open AI Standard

Solving the Integration Problem

The Model Context Protocol, commonly abbreviated MCP, is an open standard that Anthropic introduced in November 2024 to solve a specific, persistent problem in AI development: even the most capable language models are of limited use if they cannot access the data and tools relevant to a person's actual work. Before MCP, connecting an AI assistant to a company's internal database, a cloud storage service, or a project management tool typically required a custom-built integration for every single combination of AI application and data source — a fragmented approach that became unmanageable as both the number of AI tools and the number of data sources multiplied.

A Universal Connector

MCP has frequently been described, including by Anthropic itself, as something like a USB-C port for AI: a single, standardized interface that lets any compliant AI application connect to any compliant data source or tool without needing bespoke code for each pairing. Under MCP's architecture, developers can expose their data and tools through what's called an MCP server, while AI applications — referred to as MCP clients or hosts — connect to those servers to read information and trigger actions on the AI's behalf, all subject to permissions the user controls.

Core Building Blocks

MCP defines a small set of core primitives that structure how servers and AI applications interact. Tools are executable functions the AI can call to take an action, such as querying a database or sending a message. Resources are structured, file-like data the server can make available to the AI for added context, such as a document or a set of API results. Prompts are predefined instruction templates that help guide how the AI interacts with a particular system. Together, these primitives let a developer expose exactly the right level of access and functionality for a given use case.

Rapid, Industry-Wide Adoption

Since its November 2024 launch, MCP has spread well beyond Anthropic's own products. OpenAI formally adopted the protocol in March 2025 and later integrated it across the ChatGPT desktop app, and Google DeepMind has likewise adopted it. Thousands of community-built MCP servers now exist for popular tools and services, and major coding and development platforms have built MCP support directly into their products. In December 2025, Anthropic donated MCP to a newly formed Agentic AI Foundation, a directed fund under the Linux Foundation co-founded by Anthropic, Block, and OpenAI, formalizing MCP's status as vendor-neutral, shared infrastructure for the AI industry rather than a tool controlled by any single company.

Security and Permissions

Because MCP grants AI systems the ability to read potentially sensitive data and take real actions, the protocol places significant emphasis on access control. Implementations typically rely on encrypted connections for remote servers, authentication standards such as OAuth, and explicit user permission prompts before an AI assistant is allowed to access a particular data source or carry out a particular action, such as sending an email or modifying a file.

Why It Matters

For everyday users, MCP's significance is mostly invisible but practically important: it is part of the underlying plumbing that lets an AI assistant like Claude actually look something up in your calendar, search your company's internal documents, or book a service on your behalf, rather than being limited to general knowledge baked in during training. As MCP adoption has spread across the AI industry, it has become one of the more consequential pieces of shared technical infrastructure to emerge from the recent wave of AI assistant development.