Kimi K3.1 Pro just dropped - i made it race Opus 5.5 to build one game | LAB 0029

Kimi K3.1 Pro just dropped, so i gave it and Opus 5.5 the exact same prompt: build me a 3D game where you're a Perth plumber racing to call-outs. one game cost $1.08, the other $3.21 (API-equivalent, one shot each), and only one of them got Perth. i play both blind before i tell you which model built which. also this week: OpenAI paused its best models for 11 days after a settings mistake gave one a little bit of internet during training, Cursor's agents can now drive your whole computer, Block's Dessa is the most human AI voice i've heard (waitlist only), and Grok Bot's new Vault can sign in and check out for you. the practical - one prompt that makes your site work on the iPhone Duo's big inner screen. paste it into Claude Code inside your project. it screenshots every page at the Duo sizes before it changes anything, writes a check that fails first, fixes it until it passes, and leaves your normal phone and desktop layouts alone. on my site, 9 checks failed before the fix and all 18 passed after. the catch: those Duo sizes come from a simulator, not Apple, so measure your own Duo first and put your numbers in the prompt. the prompt: make this site work well on the iphone duo's big inner screen. work on a new git branch, draft only: never push, merge or deploy. 1. find every width breakpoint in the code and list them. 2. run the app locally. with playwright, screenshot every main page at 382x580, 669x825, 870x669, 951x543, plus a normal phone (390x844) and desktop (1440x900), before changing anything. save them in a before folder. 3. add a fold layout for screens roughly 600 to 1000px wide. where the app has a list plus detail, or a sidebar, show two panes side by side. make every tap target at least 44px, make sure nothing hides under fixed buttons, and respect safe-area insets (left and right). 4. write a playwright check for those rules (no sideways scroll, tap targets, two panes). run it first and show it failing. then make the fix and show it passing. 5. screenshot the same sizes again into an after folder. the 390x844 and 1440x900 layouts must not change at all. 6. finish with a before/after table: size, what was wrong, what changed. links Kimi K3.1 Pro launch: https://x.com/Kimi_Moonshot/status/2113680701770068067 OpenAI on securing its training environment: https://openai.com/index/securing-our-frontier-model-training-environment/ OpenAI on the Hugging Face incident: https://openai.com/index/hugging-face-incident-and-the-road-ahead/ Cursor's agents can drive your computer: https://x.com/cursor_ai/status/2113661506634305834 Jack Dorsey on Dessa: https://x.com/jack/status/2113697902916751661 Dessa waitlist: https://block.xyz/dessa Grok Bot's Vault: https://x.com/bot/status/2113717946019397910 Grok Bot changelog: https://x.ai/changelog/bot Marc Lou's site on the iPhone Duo: https://x.com/marclou/status/2113588729675694385 Greg Isenberg on Duo apps: https://x.com/gregisenberg/status/2113271458168279286 chapters 0:00 two models, one prompt, one game 0:13 Kimi K3.1 vs Opus 5.5: the blind test 3:07 Lenny's AI Builders 3:21 agents are getting hands 3:42 OpenAI's agents broke out of the box 5:17 Cursor can drive your computer 6:27 sponsor: Threadify 7:41 Dessa: voice agents woke up 9:15 Grok Bot can check out for you 10:43 your site is broken on the iPhone Duo 12:06 the prompt: make your site work on the Duo 13:37 see you next episode thanks to today's sponsor, my software Threadify - your lead generation agent for Threads, X and YouTube. my agents run it for me straight from Claude, and nothing goes out until i say yes. start your free 7-day trial: https://www.threadify.app/home?utm_source=youtube&utm_medium=video&utm_campaign=lab-0029&utm_content=sponsor&video_slug=lab-0029&cta_slot=youtube_description&entry_angle=agent_mcp want to sponsor a future episode? [e-mail] watch the full episode: https://www.youtube.com/watch?v=6LmucdqB0wU

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less scrolling. more “oh shit, i could use that.”

i’m Lennox. i dig through the AI updates worth your time, then test tools, models and agents on real work. what worked, what broke, and what you can try yourself.

for people making products, content and useful systems with AI. you don’t need to write code to build something worth using. grab the field notes for prompts, steps and the bits to watch out for: https://lennoxsaint.com/lab

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