MCP server
A program that implements the Model Context Protocol and exposes tools, resources, or prompts to an LLM client. Typical examples: a filesystem server, a GitHub server, a Postgres server. Servers run locally or remotely and communicate over stdio or HTTP.
Background
An MCP server is the provider side of the Model Context Protocol. It registers a set of capabilities — tools (callable functions), resources (read-only data), and prompts (parameterised templates) — and a connected client invokes them when the underlying LLM requests them. Servers are usually small, single-purpose, and stateless. The official MCP SDKs ship in TypeScript, Python, Kotlin, Swift, and Rust. Anthropic publishes a registry of reference servers (filesystem, git, postgres, brave-search, etc.) and a growing third-party ecosystem.
Tools that use it
- 01→Cursor
VS Code-based, agent-first coding environment — since Cursor 3.0 the default surface is an Agents Window, not an editor.
- 02→Continue
Open-source AI code assistant for VS Code and JetBrains, with full BYOK and local-model support.
- 03→Claude Code
Anthropic's official CLI agent for Claude — runs in the terminal, edits files, executes commands, and ships PRs.