s
stdio
Local process communication
Best for: CLI tools, local dev
S
SSE
Server-Sent Events over HTTP
Best for: Remote servers, streaming
H
HTTP
Streamable HTTP (newest)
Best for: Production, stateless
MCP is transport-agnostic: the same protocol works whether the server runs on your local machine or across the internet. Understanding the transport layer is essential because it determines how you deploy, test, and scale your servers.