fix(landing): fix Core Web Vitals regressions across public marketing pages by waleedlatif1 · Pull Request #5522 · simstudioai/sim

waleedlatif1 · 2026-07-08T23:27:39Z

Summary

Root layout unconditionally rendered next-runtime-env's PublicEnvScript, which calls unstable_noStore() and silently forced every route in the app into dynamic rendering - marketing pages never got static/ISR caching despite their own revalidate. Confirmed via bun run build's route table (ƒ → ○/●) and prod's Cache-Control: private, no-store header. Gated it to self-hosted only; hosted now uses a static, build-time equivalent (app/_shell/public-env-script.tsx) that populates the same window.__ENV global.
Removed real pointer-drag handlers from the hero's decorative workflow animation - it was draggable despite being aria-hidden.
Disabled dragging/panning on the (currently unmounted) landing-preview ReactFlow canvas so it's static-by-default if it's ever wired in.
Lazy-mount the Product Demo section's duplicate HeroVisual instance via next/dynamic + IntersectionObserver instead of loading it eagerly below the fold.
Disabled Next.js <Link> prefetch on always-in-viewport /signup and /login CTAs (navbar, hero, mobile nav) so their JS isn't fetched on every pageview regardless of whether the visitor clicks.
Removed unoptimized from local blog/integration images (including the priority LCP image on every blog post), letting next/image serve resized AVIF/WebP instead of full-size originals.
Added the learnings to (landing)/CLAUDE.md (decorative-canvas-must-be-static, lazy-mount pattern, prefetch={false} convention, root-layout dynamic-rendering gotcha).

Type of Change

Bug fix / performance fix

Testing

bun run build --filter=sim with NEXT_PUBLIC_APP_URL=https://sim.ai (isHosted=true): /, /enterprise, /workflows, /solutions/*, /demo, /blog/tags, /blog/[slug], /models/[provider], /models/[provider]/[model], /integrations/[slug] all flip from ƒ to ○/●.
Verified window['__ENV'] renders correctly in the static HTML output with real values.
next start locally: response header changes from Cache-Control: private, no-cache, no-store to Cache-Control: no-cache, must-revalidate (ISR-eligible) on /.
tsc --noEmit clean (no new errors), bun run lint clean.

Checklist

Code follows project style guidelines
Self-reviewed my changes
Tests added/updated and passing
No new warnings introduced
I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

vercel · 2026-07-08T23:27:44Z

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cursor · 2026-07-08T23:27:48Z

PR Summary

Medium Risk
The root-layout env script split affects every hosted page; behavior should match prior client env reads but self-hosted vs hosted paths must stay correct.

Overview
Fixes marketing static/ISR caching and initial-load weight that were hurting Core Web Vitals.

On hosted, the root layout no longer always renders next-runtime-env's PublicEnvScript (its unstable_noStore() was forcing the whole app dynamic). Hosted now injects a build-time PublicEnvScript with the same window.__ENV shape; self-hosted still uses the runtime script.

Bundle and interaction tweaks: always-visible /signup and /login links use prefetch={false}; below-fold Product Demo HeroVisual loads via useLazyMount + next/dynamic; LandingPreviewMount shares that hook. Decorative hero workflow blocks and the landing-preview ReactFlow canvas are non-interactive (no drag/pan). Blog/integration/content images drop unoptimized so next/image can optimize. (landing)/CLAUDE.md documents these patterns.

^{Reviewed by Cursor Bugbot for commit 87cd4e5. Configure here.}

greptile-apps · 2026-07-08T23:30:43Z

Greptile Summary

This PR improves Core Web Vitals across the public landing and content pages. The main changes are:

Replaced hosted public env injection with a static script path.
Kept the runtime env script for self-hosted deployments.
Removed decorative drag and pan behavior from marketing visuals.
Lazy-mounted below-the-fold heavy visual islands.
Disabled prefetch for always-visible auth CTAs.
Switched local content images back through Next image optimization.
Documented landing-page performance rules.

Confidence Score: 5/5

This looks safe to merge.

No blocking issues found in the changed code.

Important Files Changed

Filename	Overview
apps/sim/app/_shell/public-env-script.tsx	Adds the hosted static public env script with script-safe JSON serialization.
apps/sim/app/layout.tsx	Chooses the static hosted env script or runtime self-hosted env script based on deployment mode.
apps/sim/app/(landing)/hooks/use-lazy-mount.ts	Adds a shared viewport-proximity hook for lazy mounting heavy client islands.
apps/sim/app/(landing)/components/product-demo/components/product-demo-visual-mount/product-demo-visual-mount.tsx	Wraps the product demo visual in a client-only lazy mount.
apps/sim/app/(landing)/components/hero/components/hero-platform-loop/hero-workflow-stage.tsx	Removes pointer-drag handling from the decorative workflow stage.
apps/sim/app/(landing)/components/content-post-page/content-post-page.tsx	Lets local post cover and related-post images use Next image optimization.

_{Reviews (2): Last reviewed commit: "fix(landing): escape </script> breakout ..." | Re-trigger Greptile}

… pages - root layout unconditionally rendered next-runtime-env's PublicEnvScript, which calls unstable_noStore() and silently forced every route in the app dynamic - marketing pages never got static/ISR caching despite their own revalidate. Gated it to self-hosted only; hosted now uses a static, build-time equivalent (app/_shell/public-env-script.tsx) - removed real pointer-drag handlers from the hero's decorative workflow animation (was draggable despite being aria-hidden) - disabled dragging/panning on the (currently unmounted) landing-preview ReactFlow canvas so it's static-by-default if it's ever wired in - lazy-mount the Product Demo section's duplicate HeroVisual instance via next/dynamic + IntersectionObserver instead of loading it eagerly below the fold - disabled Next.js Link prefetch on always-in-viewport /signup and /login CTAs (navbar, hero, mobile nav) so their JS isn't fetched on every pageview regardless of whether the visitor clicks - removed `unoptimized` from local blog/integration images (including the priority LCP image on every blog post), letting next/image serve resized AVIF/WebP instead of full-size originals

- revert prefetch={false} on below-fold CTAs (cta.tsx, enterprise.tsx) - contradicts the prefetch-on-approach rule this PR itself documents - restore unoptimized on avatarUrl and the MDX body-image renderer, both of which can legitimately hold external URLs outside next.config.ts's image remotePatterns allow-list - simplify handleAnchors to a single block argument now that positions are static (the second "live position" argument was always identical to the first after the drag-handler removal) - extract the near-duplicate IntersectionObserver lazy-mount logic shared by landing-preview-mount.tsx and product-demo-visual-mount.tsx into a single apps/sim/app/(landing)/hooks/use-lazy-mount.ts hook - import next-runtime-env's own exported PUBLIC_ENV_KEY constant instead of a hardcoded string literal, and match its case-insensitive NEXT_PUBLIC_ filter exactly, removing any drift risk between the two implementations - drop plain inline comments with no TSDoc home in favor of relying on the existing TSDoc/CLAUDE.md documentation

…-*-page components The blog/library split (#5516) moved the blog post/index/author JSX into shared ContentPostPage/ContentIndexPage/ContentAuthorPage components while this branch was in flight, so the original unoptimized removal (verified local-only ogImage paths for both blog and library content) needs to land on those shared components instead of the old per-route JSX.

…d structure doc - add a one-line comment on ContentFrontmatterSchema.ogImage documenting that it's rendered without unoptimized and expects a local path, matching the existing avatarUrl comment convention (a reviewer noted ogImage's schema is technically unconstrained and seo.ts has an http-prefix branch, though all current content is local) - add the new hooks/ folder to the (landing) CLAUDE.md structure diagram and name use-lazy-mount.ts directly in the lazy-mount rule

Greptile P1: a NEXT_PUBLIC_* value containing "</script>" would close the inline script early and could inject markup/script into every hosted page. Escape "<" in the serialized JSON before interpolating it, matching the standard JSON-in-script-tag safeguard.

waleedlatif1 · 2026-07-09T00:41:05Z

@greptile-apps review

waleedlatif1 · 2026-07-09T00:41:06Z

@cursor review

cursor

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit 87cd4e5. Configure here.}

greptile-apps Bot reviewed Jul 8, 2026

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Comment thread apps/sim/app/_shell/public-env-script.tsx Outdated

Comment thread apps/sim/app/(landing)/blog/components/blog-image.tsx

waleedlatif1 added 3 commits July 8, 2026 16:58

waleedlatif1 force-pushed the worktree-landing-perf-cwv branch from a4f3aaa to adf6109 Compare July 9, 2026 00:06

vercel Bot temporarily deployed to Preview July 9, 2026 00:06 Inactive

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cursor Bot reviewed Jul 9, 2026

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waleedlatif1 merged commit 7bd734c into staging Jul 9, 2026
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waleedlatif1 deleted the worktree-landing-perf-cwv branch July 9, 2026 00:49

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fix(landing): fix Core Web Vitals regressions across public marketing pages#5522

fix(landing): fix Core Web Vitals regressions across public marketing pages#5522
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waleedlatif1 commented Jul 8, 2026

Summary

Type of Change

Testing

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Confidence Score: 5/5

Important Files Changed

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