{"library":"perf_hooks","type":"library","category":null,"description":"The `perf_hooks` module is a fundamental, built-in Node.js core module that provides performance measurement APIs based on the W3C User Timing and Performance Timeline specifications. It enables developers to instrument and observe Node.js application behavior with high-resolution timers, performance marks, measures, and observers. Key APIs include `performance.now()`, `performance.mark()`, `performance.measure()`, `PerformanceObserver`, and `eventLoopUtilization()` for monitoring event loop delays. This functionality is part of Node.js itself and does not require a separate npm installation; it is stable across all supported Node.js versions (currently 18.x LTS, 20.x LTS, 22.x LTS, with new versions released regularly). Critically, the npm package `perf_hooks` (version 0.0.1) mentioned in the metadata is a long-abandoned placeholder, last published nine years ago. Despite having high weekly downloads, it offers no actual functionality and should *never* be installed or used. Users seeking performance tooling should rely exclusively on the `node:perf_hooks` core module.","language":"javascript","status":"abandoned","version":"0.0.1","tags":["javascript"],"install":[{"cmd":"npm install perf_hooks","imports":["import { performance } from 'node:perf_hooks';","const { PerformanceObserver } = require('node:perf_hooks');","import { timerify } from 'node:perf_hooks';"]},{"cmd":"yarn add perf_hooks","imports":[]},{"cmd":"pnpm add perf_hooks","imports":[]}],"homepage":null,"github":"https://github.com/mcollina/perf_hooks","docs":null,"changelog":null,"pypi":null,"npm":"https://www.npmjs.com/package/perf_hooks","openapi_spec":null,"status_page":null,"smithery":null,"compatibility":{"summary":{"python_range":"18–22","success_rate":0,"avg_install_s":null,"avg_import_s":null,"wheel_type":null},"url":"https://checklist.day/v1/registry/perf_hooks/compatibility"},"provenance":{"verified_status":null,"verified_at":null,"last_verified":"Wed Jun 17","next_check":"Sat Jul 18","install_tag":null}}