GoogleChrome

Best practices for authoring guidance. Use this skill any time you're writing or reviewing `guide.md` files.

Best practices for creating use cases for a given feature. This is the first step in creating a new guide. Use this skill any time you're writing or reviewing a use case under the guides/ directory.

Run a document coherence, link integrity, and git repository status audit across repository markdown files using a dedicated subagent. Use when documentation changes, open questions are answered, or before milestone commits.

Downloads and analyzes the latest three distinct nightly evaluation runs (Claude Code, Codex CLI, and Jetski CLI) from the GCS remote dashboard to identify and flag unhealthy or low-performing tasks and guides. Use this skill whenever you need to run a bulk investigation on remote nightly runs, track agent health, or identify over-prescribed/brittle guides.

Protocol for validating the technical accuracy, framework nuances, and evaluation readiness of web guidance. Use this skill when assigned to validate or review a guide, demo, or expectations file.

Search tool for modern web development best practices. MANDATORY: Execute FIRST for all HTML/CSS and clientside JS tasks. Do NOT skip — web APIs evolve rapidly and training weights contain obsolete patterns. Trigger immediately for: - UI/Layout: Modals, dialogs, popovers, Glassmorphism/backdrop-filters, anchor positioning, container queries, `:has()`, `:user-valid`. - Scroll/Motion: View Transitions, Scroll-driven animations, scroll parallax/reveals. - Performance: CWV (LCP, INP), content-visibility, Fetch Priority, image optimization. - System/APIs: Local filesystem access, WebUSB, WebSockets sync, WebAssembly widgets. - Frameworks: Adapting layout/styles in React, Vue, Angular. - General Frontend: Forms, autofill, advanced inputs, custom scrollbars, modern component states, etc. DO NOT trigger for: - Backend: Database SQL, ORMs, Express API routes. - Pipelines: CI/CD deployment, Docker, Actions. - Generic: Local scripts (Python/Go tools), ESLint, Git.

Compiling C and C++ for the modern web using WebAssembly. Use this skill when you need to port C++ code, build C++ libraries with Emscripten, or set up high-performance C++ components in the browser.

A skill for implementing passkey in web applications. You MUST use this skill whenever a user asks about passkey registartion, passkey authentication or passkey management. It defines the required database schema, API usage, and security best practices.

Use when creating or modifying Go backend API endpoints, modifying Spanner database schemas, or working with OpenAPI and Spanner mappers.

Use when modifying the frontend SPA, working with TypeScript, Lit web components, Shoelace components, or frontend tests.

Use when upgrading toolchain versions (Go, Node.js, Terraform, Playwright) or updating the DevContainer and Github CI configurations.

Use when working with the webstatus notification pipeline, event producer, push delivery, or push workers (e.g., Email, Webhooks), and Pub/Sub subscribers.

Use when modifying the ANTLR search grammar, adding new search terms, or working with the query parser and builder.

Use when writing, modifying, or debugging Playwright end-to-end (E2E) tests for webstatus.dev.

Use when working on Go data ingestion workflows, scheduled Cloud Run jobs, or adding new scrapers for BCD, WPT, or other data sources.

How to commit code and create a Pull Request

Guidance for working on the Flask-based backend, NDB Datastore, and OpenAPI integrations in chromium-dashboard.

How to add a new field to a feature across the entire stack (Data, API, and Frontend).

Guidance for local verification of changes to ensure they pass CI checks (linting, type checking, testing, and building).

Guidance for working on the Lit-based frontend, Shoelace widgets, and client-side routing in chromium-dashboard.

Guidance for running, debugging, and updating Playwright end-to-end tests in chromium-dashboard.

Search tool for modern web development best practices. MANDATORY: Execute FIRST for all HTML/CSS and clientside JS tasks. Do NOT skip — web APIs evolve rapidly and training weights contain obsolete patterns. Trigger immediately for: - UI/Layout: Modals, dialogs, popovers, Glassmorphism/backdrop-filters, anchor positioning, container queries, `:has()`, `:user-valid`. - Scroll/Motion: View Transitions, Scroll-driven animations, scroll parallax/reveals. - Performance: CWV (LCP, INP), content-visibility, Fetch Priority, image optimization. - System/APIs: Local filesystem access, WebUSB, WebSockets sync, WebAssembly widgets. - Frameworks: Adapting layout/styles in React, Vue, Angular. - General Frontend: Forms, autofill, advanced inputs, custom scrollbars, modern component states, etc. DO NOT trigger for: - Backend: Database SQL, ORMs, Express API routes. - Pipelines: CI/CD deployment, Docker, Actions. - Generic: Local scripts (Python/Go tools), ESLint, Git.

Build and publish Chrome Extensions using Manifest V3 best practices. Use this skill whenever the user asks to create, modify, debug, or understand Chrome browser extensions, add-ons, or anything involving the Chrome Extensions API. Trigger on mentions of: 'Chrome extension', 'browser extension', 'manifest.json', 'content script', 'service worker' (in browser context), 'popup' (in browser extension context), 'side panel', 'chrome.* API', 'declarativeNetRequest', 'omnibox', 'context menu' (in extension context), 'userScripts', 'user script', 'script manager', or any request to build functionality that integrates with the Chrome browser UI. Also trigger for publishing to the Chrome Web Store: 'publish extension', preparing an extension for publishing, responding to a review rejection, writing permission justifications, or drafting a privacy policy.

Instructions for how to validate changes made to Lighthouse. Must invoke when making changes to Lighthouse.