Glossary
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 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.