MCP Server Development#

This reference covers building MCP servers from scratch – the server lifecycle, defining tools with proper JSON Schema, exposing resources, choosing transports, handling errors, and testing the result. If you want to understand when to use MCP versus alternatives, see the companion article on MCP Server Patterns. This article focuses on how to build one.

Server Lifecycle#

An MCP server goes through four phases: initialization, capability negotiation, operation, and shutdown.

MCP Server Patterns#

Model Context Protocol (MCP) is Anthropic’s open standard for connecting AI agents to external tools and data. Instead of every agent framework inventing its own tool integration format, MCP provides a single protocol that any agent can speak.

An agent that supports MCP can discover tools at runtime, understand their inputs and outputs, and invoke them – without hardcoded integration code for each tool.

Server Structure: Three Primitives#

An MCP server exposes three types of capabilities: