Lenny’s AI Builders

Meta just gave away Muse Spark Open, which it calls its most capable US open-weight model. the catch: to run it yourself you need two Mac Studios (or rent it on OpenRouter from $1.25 per million tokens in). so i put it on BuilderBench, my own benchmark, against Meta's paid Muse Wonder Full. the result: Meta's free model scored 27.68. its own paid Muse Wonder Full scored 42.52 and Google's Gemini 4 Argon 45.68 - same tasks only (the desk tasks weren't run), rated by me. also this week: Opus 5.5 fast mode with no waitlist ($8 in / $40 out per million tokens), Claude Code Review for Team and Enterprise, ChatGPT driving your Chrome (and GPT-Live 1.1), Dan Shipper's "the newsletter is dead" and Marc Lou's MailCheap, and Nick Cammarata on reading an AI's mind. the practical: Felix Rieseberg's "deeper version, not a bigger one" prompt, tested on my newsletter with a blind judge from a different AI. Felix's article: https://felixrieseberg.com/how-to-be-more-ambitious-a-tutorial-for-humans-with-models/ chapters 0:00 Meta's free model has a catch 0:22 Muse Spark Open: free weights, two Mac Studios 2:01 this is the LAB 2:17 everything got cheaper, faster or free 2:27 Opus 5.5 fast mode, no waitlist 3:58 Claude Code Review goes live 5:21 sponsor: Threadify 6:43 ChatGPT now drives your Chrome 7:50 the newsletter is dead + MailCheap 10:47 reading an AI's mind 12:14 ask for a deeper version, not a bigger one 13:55 Meta's free model on my bench: the score 14:33 outro thanks to today's sponsor, my software Threadify - your lead generation agent: https://www.threadify.app/home?utm_source=youtube&utm_medium=video&utm_campaign=lab-0023&utm_content=sponsor want to sponsor a future episode? sponsors@lennysaibuilders.com watch the full episode: https://youtu.be/UapnTPlIO04

What is Lenny’s AI Builders?

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

this feed also keeps the earlier L E S S O N S episodes from my journey building with AI.