MCP Sampling
An MCP feature that lets a server request a completion from the client's LLM, so the server can use model reasoning without holding its own API key.
Analogy
Like a contractor borrowing the homeowner's tools instead of buying their own: the server asks the client to do the thinking.
Why it matters
It lets an MCP server add AI reasoning steps while keeping model access and cost controlled on the client side.
In practice
A summarization server asking the client's model to condense a fetched document before returning it.