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Use when moving a Butterbase app between regions, checking migration progress, aborting a stuck move, reverse-rolling a completed move, or tearing down retained source replicas after a move is stable

Use when building features that join, record, or transcribe Zoom/Meet/Teams/Webex calls — meeting bots, call notetakers, sales-call summarizers, interview transcribers. Covers ctx.ai.meetings.start/get/stop/list, webhook setup, and credit metering.

Use when applies to any page embedding or hosting video content (YouTube, Vimeo, self-hosted). Use when adding video content to a site or auditing structured data coverage.

Use when reviewing CI coverage, automated checks, or test strategy related to Write unit tests. Focus on whether the rule is continuously verified, not just documented.

Use when reviewing CI coverage, automated checks, or test strategy related to Maintain test coverage thresholds. Focus on whether the rule is continuously verified, not just documented.

Use when reviewing image assets, markup, and CDN or build transforms related to Optimize SVG files. Check encoded size, rendered size, loading strategy, and above-the-fold impact together.

Use when performing accessibility audits of web pages, components, or full user flows. Applies to all web content accessed via assistive technology. Particularly important for custom JavaScript widgets, single-page applications, dynamically updated content, modal dialogs, and forms with validation.

Use when applies to product pages, local business pages, recipes, apps, books, and any page that aggregates user reviews. Use when auditing rich result eligibility for e-commerce or review sites.

Use when reviewing whether a website has a visible, accessible privacy policy link, particularly in the footer navigation.

Use when reviewing scripts, client components, bundles, or runtime behavior related to Use modern array and object methods. Inspect both source code and the browser execution path so fixes target the real bottleneck or bug.

Use when reviewing rendered HTML, interactive components, or design-system patterns related to Make modal dialogs keyboard accessible. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.

Use when reviewing CI coverage, automated checks, or test strategy related to Follow mocking best practices. Focus on whether the rule is continuously verified, not just documented.

Use when reviewing an HTTPS page for resources (scripts, images, stylesheets, iframes) that are loaded over plain HTTP.

Use when auditing server configuration or diagnosing broken resources. Applies to any web server serving HTML, CSS, JS, images, fonts, or other static assets.

Use when auditing page metadata or generating SEO-optimized titles. Applies to every HTML page that should appear in search results.

Use when reviewing rendered HTML, interactive components, or design-system patterns related to Avoid meta refresh redirects. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.

Use when auditing HTML document structure. Applies to any page where meta tags (noindex, canonical-url, description, viewport, OG tags) may have been injected into the body by CMS plugins, widgets, or JavaScript rendering.

Use when auditing page metadata or generating descriptions for new pages. Applies to every page that should receive organic search traffic.

Use when reviewing scripts, client components, bundles, or runtime behavior related to Prevent common memory leak patterns. Inspect both source code and the browser execution path so fixes target the real bottleneck or bug.

Use when auditing URL structure or configuring a new site's routing. Applies to any server or framework that allows case-insensitive file systems (Linux servers are case-sensitive by default).

Use when reviewing stylesheets, component styles, and responsive behavior related to Use CSS logical properties for i18n and RTL support. Check the rendered layout across breakpoints and interaction states before proposing a fix.

Use when reviewing image assets, icon libraries, or components that render illustrations to identify culture-specific content that may need locale overrides or replacement with neutral alternatives.

Use when auditing a local business website's structured data. Applies to any business that serves customers at a physical location or specific geographic area.

Use when auditing slow page loads, heavy assets, or rendering delays related to Show loading indicators. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

Use when auditing public documentation portals, API references, help centers, SDK docs, or large knowledge bases. Check the final file served at `/llms.txt` and verify that the linked pages are stable, high-value, and accessible without relying on a JavaScript-only interface.

Use when auditing content pages for AI discoverability. Applies to any informational page intended to appear in AI-generated answers, search snippets, or knowledge base extraction.

Use when reviewing dashboards, admin tables, search results, or feeds with many repeated items. Confirm the bottleneck is DOM or rendering cost before introducing virtualization because small lists usually do not need the added complexity.

Use when reviewing rendered HTML, interactive components, or design-system patterns related to Use correct list structure. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.

Use when reviewing rendered HTML, interactive components, or design-system patterns related to Use descriptive link text. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.

Use when reviewing templates, rendered HTML, or shared components related to Check for broken links. Validate the final browser-facing markup, not just the source framework abstraction.

Use when generating URL slugs from article titles, auditing URL structures for unnecessary depth or length, or reviewing URL patterns in a CMS or router configuration.

Use when auditing slow page loads, heavy assets, or rendering delays related to Avoid serving legacy JavaScript to modern browsers. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

Use when reviewing client-side JavaScript, HTML source, or git history for exposed credentials, API keys, or tokens.

Use when auditing slow page loads, heavy assets, or rendering delays related to Implement lazy loading for offscreen content. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes. Absence of `loading='lazy'` is not enough by itself when fold position is unknown.

Use when auditing slow page loads, heavy assets, or rendering delays related to Disable lazy loading for above-the-fold content. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

Use when auditing slow page loads, heavy assets, or rendering delays related to Optimize largest contentful paint. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

Use when reviewing rendered HTML, interactive components, or design-system patterns related to Use landmark regions correctly. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.

Use when reviewing rendered HTML, interactive components, or design-system patterns related to Use exactly one main landmark. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.

Use when reviewing rendered HTML, interactive components, or design-system patterns related to Align visible labels with accessible names. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.

Use when auditing content pages for over-optimisation, reviewing AI-generated content that may repeat target phrases excessively, or checking meta tags and alt text for unnatural keyword accumulation.

Use when reviewing rendered HTML, interactive components, or design-system patterns related to Enable keyboard navigation for all elements. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.

Use when reviewing scripts, client components, bundles, or runtime behavior related to Parse JSON safely with error handling. Inspect both source code and the browser execution path so fixes target the real bottleneck or bug.

Use when auditing slow page loads, heavy assets, or rendering delays related to Avoid JavaScript-based redirects. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

Use when auditing slow page loads, heavy assets, or rendering delays related to Use secure and up-to-date JS libraries. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

Use when auditing slow page loads, heavy assets, or rendering delays related to Optimize JavaScript bundle size. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

Use when reviewing scripts, client components, bundles, or runtime behavior related to Minify all JavaScript files. Inspect both source code and the browser execution path so fixes target the real bottleneck or bug.

Use when reviewing scripts, client components, bundles, or runtime behavior related to Lint JavaScript code. Inspect both source code and the browser execution path so fixes target the real bottleneck or bug.

Use when reviewing scripts, client components, bundles, or runtime behavior related to Avoid inline JavaScript. Inspect both source code and the browser execution path so fixes target the real bottleneck or bug.

Use when applies to CSS and JavaScript implementations of modals, overlays, pop-ups, cookie banners, newsletter sign-up dialogs, and promotional overlays. Check for `position: fixed`, `position: absolute` with large z-index, backdrop overlays, and JavaScript that shows modals on page load or shortly after. Consider both SEO impact (Google) and accessibility (WCAG focus management).

Use when auditing a site's internal link structure, identifying pages that need more incoming links, generating contextual linking opportunities between related content, or reviewing a CMS template's internal linking patterns.

Use when auditing slow page loads, heavy assets, or rendering delays related to Optimize interaction to next paint. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

Use when reviewing CI coverage, automated checks, or test strategy related to Write integration tests for key workflows. Focus on whether the rule is continuously verified, not just documented.

Use when reviewing templates, rendered HTML, or shared components related to Use semantic input type attributes. Validate the final browser-facing markup, not just the source framework abstraction.

Use when reviewing rendered HTML, interactive components, or design-system patterns related to Provide alt text for image buttons. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.

Use when auditing a site for indexability issues, investigating why pages appear in Google's index that should be excluded (or vice versa), or reviewing robots.txt and meta robots configurations for consistency.

Use when auditing a site for accidental noindex directives, investigating why important pages are not appearing in Google Search, or reviewing CMS settings that control indexing at the page or category level.

Use when reviewing rendered HTML, interactive components, or design-system patterns related to Use inclusive language. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.

Use when reviewing or improving a Front-End Checklist rule MDX file to raise its quality score, fix stub prompts, add missing fields, or enrich content with real code examples.

Use when reviewing long pages, dashboards, or content feeds with expensive offscreen modules. Balance early enough loading for smooth scrolling against keeping the initial route light.

Use when reviewing slow initial loads caused by optional features. Prioritize code that is expensive to download or execute and not required for the first viewport, first input, or core task completion.