I built an autumn foliage simulator with Grok 4.7, and I never touched a laptop. The prompt: one self-contained HTML file, layered paper-cutout style. A big tree, rolling hills behind it, grass in front. At least 1,500 leaves that detach, flutter, and pile up on the ground. Drag a finger to blow a gust. Add a wind slider and a Regrow button. It has to run at 60 fps on an iPhone. The new workflow: 1. I texted the prompt to my Grok Bot assistant. 2. Grok Bot launched a Cursor cloud agent running Grok 4.7. 3. The agent wrote the file, ran it in a headless browser, checked the console, and sent back the code and a screenshot. 4. I opened the HTML file on my iPhone and screen-recorded it. No copy and paste. No editor. About 22 minutes from prompt to a running sim. What Grok 4.7 built, which it named "Paper Autumn": - 34.6 KB, one file - 2,000 leaves - A cream sky with three puffy cloud cutouts - Rolling hills in layers of tan, dusty rose, sienna and light brown - A dark brown angular tree, thick with golden yellow, burnt orange, deep red and brown leaves - Sharp blades of grass in forest green, olive and lime across the bottom - Soft drop shadows between every layer, so it looks like stacked craft paper - Leaves flutter down and pile up on a ridge at the base of the hills - A drag gust that shakes the branches - A dark red wind slider and Regrow button, plus a live count of leaves still on the tree - Zero console errors My take on the phone: it worked very well on my iPhone, and recording it was very smooth. The part I like most is that I describe the build in a text message and judge the finished result. The assistant handles the rest. The exact prompt are in the first comment.

Build a single self-contained HTML file (all CSS and JavaScript inline; any library only from a CDN) that opens directly in a browser and works on an iPhone in Safari with touch. Make an autumn foliage simulator in a layered paper-cutout style: a large tree in the middle ground, rolling hills behind it, and grass in front. Every shape should look like cut colored paper with slightly rough edges, a subtle paper-grain texture, and soft drop shadows between layers. The tree holds at least 1,500 individual leaves in mixed reds, oranges, yellows and browns. Leaves slowly detach and fall with a realistic flutter (tumbling and drifting side to side, not straight down) and pile up on the ground where they land. Dragging a finger or the mouse across the screen creates a gust in that direction that blows both falling and settled leaves around and shakes the branches. Add a wind-strength slider and a "Regrow" button that refills the tree. Keep it at a smooth 60 fps on a phone.

I gave Sonnet 5.5 a hard one: build an autumn foliage simulator in a single HTML file. Layered paper-cutout look. Big tree, rolling hills, grass. Rough-edged paper, grain, soft shadows. 1,500+ leaves that flutter down (not straight down) and pile up. Drag a finger to make a gust that blows falling and settled leaves and shakes the branches. Wind slider. Regrow button. 60 fps on iPhone. The result: a 23 KB file that ran on the first try. The leaves did everything I asked. It looks stellar. Totally nailed it. Setup: I ran it through the Nous Research portal, with my Hermes agent as the orchestrator. Full prompt and in the first comment.

Local model test on my DGX Spark: Qwen 3.8 Flash vs. a V8 engine. One HTML file. Code-only geometry. 8 pistons in firing order, exploded view, X-ray mode, touch orbit on iPhone. No cloud. Full prompt in the first comment.