MCP server

An MCP server is the program on the other end of MCP. It exposes a set of tools (functions the agent can call) and sometimes resources (data it can read). The agent discovers those tools and uses them during a task.

Servers run in one of two ways. A local server runs as a process on your machine, launched with npx or uvx. A remote server is hosted, and you connect over HTTP with OAuth or a token; a hosted tracker such as Linear runs this kind of remote server. Your client lists the servers it should start in a config file; the config builder writes one per client. A filesystem server, for instance, exposes read and write tools scoped to the folders you allow.