These are my notes from working through it — what MCP actually is, how the wire protocol is shaped, what the primitives mean in practice, and where the protocol is heading.
## What MCP is
MCP is an open protocol that standardizes how LLM applications connect to tools and data sources. The pitch is one analogy: REST standardized how web apps talk to backends, LSP standardized how IDEs talk to language tooling, MCP standardizes how AI applications talk to external systems.