Watchman
lastmod 2026-11-10created 2022-07-203 edits
Watchman is a file change watching service made by Facebook (Meta). It watches specified directory trees and, when files change, runs registered commands or notifies clients. It abstracts OS-specific notification APIs (inotify, FSEvents, etc.) and is designed to return query results quickly even in large repositories. Tools such as Buck, Jest, and Mercurial use it as their change detection backend.
A file watching service