MCP Explained: Build AI Integrations with Tools, Resources & OAuth (2026 Guide)

Anthropic introduced the Model Context Protocol (MCP) in November 2024 to enable large language models (LLMs) to interact seamlessly with external tools and data sources, addressing their inability to perform tasks like checking calendars or sending messages. MCP employs a client-server architecture using JSON-RPC 2.0, inspired by the Language Server Protocol, allowing AI applications to connect with various services such as databases and communication platforms through standardized integrations. It defines three primitives—Tools, Resources, and Prompts—to handle different interaction types, with Tools executing functions, Resources providing read-only data, and Prompts standardizing task interactions. The protocol gained rapid adoption, with major tech companies like OpenAI and Google DeepMind integrating it, and by December 2025, it was donated to the Linux Foundation. MCP servers can be built in languages like Python and TypeScript, with FastMCP being the standard framework for Python, and security is a central concern, with practices outlined to mitigate risks like token mismanagement and prompt injection. The protocol is suitable for scenarios requiring AI to interact with multiple services, offering broad compatibility and security but may add complexity for simpler use cases.