fastlane

Executes performance and network analysis on websites using the Speculation Rules API for background prerendering, prefetching, mixed eagerness rule sets, and instant page transitions. Use when identifying high-intent candidate pages for speculative loading, injecting and testing dynamic speculation rules (list or document rules with exclusions and server-side tags), automating hover triggers via Chrome DevTools for Agents, capturing and isolating background Prerender WebContents network requests across CDP targets (including Sec-Speculation-Tags headers), or implementing activation hold-back deferral logic for ad monetization and analytics scripts. Don't use for Single Page Applications (SPAs), legacy <link rel="prerender"> tags, or general web performance audits unrelated to the Speculation Rules API.

Implements slot-level 'pos' key-value targeting (pos='1', pos='2') in existing publisher GPT ad unit code and provides step-by-step guidelines for updating Google Ad Manager (GAM) settings (Key-Values, Reportable dimensions, Reporting, Line Items). Use when modifying existing ad code to track position-based viewability decay or configuring GAM inventory settings.

Migrates mobile applications from deprecated AdMob banner formats (Smart Banners, Standard Banners, and Legacy Anchored Adaptive Banners) to the Large Adaptive Anchor API and Next-Gen GMA SDK. Use when upgrading to the Large Adaptive Anchor API (getLargeAnchoredAdaptiveBannerAdSize), migrating to Android GMA SDK v25.0.0+ or iOS GMA SDK v13.0.0+, implementing Google Mobile Ads in Flutter (google_mobile_ads v9.0.0+), or troubleshooting AdMob banner layout constraints, height, and overlapping issues. Don't use for interstitial, rewarded, or native ad formats.