For about fifteen years the promise of on-demand manufacturing was the same: upload a file, get a price, get a part. That promise was kept. What nobody built was the layer above it, the part where something other than a human does the uploading. That layer arrived in 2026, quietly, in the form of protocol announcements rather than product launches. The trend worth naming is the collapse of three previously separate stacks into one addressable pipeline.

Table of Contents What is MCP? Core Concepts Architecture Getting Started Building an MCP Server Building an MCP Client Transport Mechanisms Tools, Resources & Prompts Security Considerations Debugging & Testing Real-World Examples What is MCP? Model Context Protocol (MCP) is an open standard developed by Anthropic that enables AI models to securely connect with external data sources, tools, and services. It defines a universal, open protocol for how AI applications communicate with the outside world.