---
title: "MCP server · MacMelon"
description: "An MCP server is a helper program an AI app starts to reach tools and data. Local MCP servers run on your Mac and can outlive the app that started them."
url: "https://macmelon.com/glossary/mcp-server"
---

# MCP server

A helper program that gives an AI app access to a tool or data source, often running as a separate process on your Mac.

The Model Context Protocol, MCP, is a way for AI apps to talk to tools: a file system, a browser, a database, an issue tracker. Many MCP servers run locally as separate processes that the AI app starts. Coding tools may start their own copy of every configured server for each session, so several open sessions mean several copies.

When the AI app or its terminal closes, those processes are supposed to exit. Some do not. [Sentinely](https://macmelon.com/apps/sentinely) looks for MCP servers whose app has closed and for duplicate copies started by the same app, and stops them after you review. See [Stop AI-tool helpers left running after you close your editor](https://macmelon.com/use-cases/stop-leftover-ai-helpers-and-mcp-servers).

## Apps

[No more Force Quit in the middle of a build. ### Sentinely](https://macmelon.com/apps/sentinely)

## Related guides

[### How to find what's slowing down your Mac](https://macmelon.com/guides/how-to-find-what-is-slowing-down-your-mac)

## Related use cases

[### Stop AI-tool helpers left running after you close your editor](https://macmelon.com/use-cases/stop-leftover-ai-helpers-and-mcp-servers)

## Related terms

[The background process that gives a code editor autocomplete, go-to-definition, and error checking for a language. ### Language server](https://macmelon.com/glossary/language-server)[The memory macOS charges to a process, including memory it has compressed. Sentinely's unit for estimates and receipts. ### Memory footprint](https://macmelon.com/glossary/memory-footprint)[Watched-folder cleanup in Disk Housekeeper, still behind a preview. In Sentinely, the memory fixes you have approved. ### Autopilot](https://macmelon.com/glossary/autopilot)