Measures Core Web Vitals for one representative URL per page template (plus priority pages) by running Lighthouse through npx with Chrome, three runs per URL with the median run kept (a majority must succeed).
Measures Core Web Vitals for one representative URL per page template (plus priority pages) by running Lighthouse through npx with Chrome, three runs per URL with the median run kept (a majority must succeed), and optionally reads real-user field data from the Chrome UX Report API when the owner supplies a key in an environment variable - judging LCP, CLS and INP (TBT as the lab proxy) against Google's published bands, labelling lab versus field and local versus deployed honestly, ending in a PASS/FAIL/BLOCKED gate that is BLOCKED, never PASS, without Lighthouse or Chrome. Use when someone asks "check our Core Web Vitals", "which page templates are slow", "run Lighthouse across the site", "is our LCP good", "page speed audit by template", or as the fifth step of this pack. Do NOT use for one-off speed tests of a single URL (PageSpeed Insights is free), for load testing, or as proof of real-user experience when only lab data was collected.This is the skill's description: the text your AI reads to decide when the skill applies.
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core-web-vitals-lab/SKILL.md
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name: core-web-vitals-lab
description: Measures Core Web Vitals for one representative URL per page template (plus priority pages) by running Lighthouse through npx with Chrome, three runs per URL with the median run kept (a majority must succeed), and optionally reads real-user field data from the Chrome UX Report API when the owner supplies a key in an environment variable - judging LCP, CLS and INP (TBT as the lab proxy) against Google's published bands, labelling lab versus field and local versus deployed honestly, ending in a PASS/FAIL/BLOCKED gate that is BLOCKED, never PASS, without Lighthouse or Chrome. Use when someone asks "check our Core Web Vitals", "which page templates are slow", "run Lighthouse across the site", "is our LCP good", "page speed audit by template", or as the fifth step of this pack. Do NOT use for one-off speed tests of a single URL (PageSpeed Insights is free), for load testing, or as proof of real-user experience when only lab data was collected.
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