ThursdAI Special - OpenAI's Romain Huet on Codex's 5M users, GPT-5.6 & the Golden Age of AI Engineering

Hey everyone, Alex here 👋This week’s episode is a little different. As you’re reading this, I’m flying back from my 40th birthday trip with the family, and while the guys did end up having a great live stream (Huge thanks to Yam for hosting!), here I will bring you the episode I pre-recorded before leaving for the trip. However, tons of news happened this week, and as always, there’s a TL;DR section below with the top most important news in AI this week!⏰ CHAPTERS:0:00 — Cold open: this week is a special one2:50 — How I use Sol & Fable: papercut-fixing with Computer Use8:43 — Fable Max: trip site, kids' newspapers & the perfect packing list12:06 — Rebuilding ThursdAI's openers with HyperFrames15:53 — Romain Huet (OpenAI): the golden age of AI engineering17:49 — Codex's inflection point: 5M weekly users & company-wide adoption20:36 — /goal, AppShots & Codex managing its own threads23:59 — GPT-5.6 Sol, Terra & Luna: value maxing & 750 tok/s on Cerebras25:56 — Why prompting techniques are dying28:01 — Voice + reasoning: the next interface for Codex & ChatGPT29:47 — Romain's closing + OpenAI booth tour31:25 — Insecure Agents pod: AI evangelism vs doomerism37:25 — Wolfbench: transparent evals, token costs & surprising results40:45 — Token billionaires: when loops are worth the spend44:07 — Agent security & the hot take: prompt injection is solved49:22 — Deepfakes, voice cloning & why open access makes us safer53:35 — Final takeaways: the hallway track & AI Engineer Tel AvivHere’s what’s on today’s special episode. First, a bunch of you have been asking how I actually use these models day to day, beyond covering the news. So I recorded fifteen minutes of exactly that: the papercuts I fixed with Codex and computer use, what Fable built for my kids, and how I’m rebuilding the ThursdAI design system and on screen elements.Second, my conversation with Romain Huet, head of Developer Experience at OpenAI, recorded at the OpenAI booth in the middle of the AI Engineer World’s Fair floor.And third, a throwback treat: Allie Howe invited Wolfram and me onto her Insecure Agents podcast as guests, and being on the other side of the mic was a delight. Let’s get into it.How I actually use AI: a papercut-fixing spreeI promised a few of you I’d take time on the show to talk about the stuff I build and fix with AI, not just the news. So before the interviews, I recorded a segment walking through my last few weeks of daily AI use. Use the chapters if you want to skip ahead, but why would you?Codex with computer use fixed every Mac annoyance I hadOnce OpenAI launched GPT 5.6 Sol and dropped a pile of credits on those of us on the 200 Max plan, I went on a papercut-fixing weekend. The rule was simple: every little thing that has annoyed me about my Mac for years, I ask Codex to fix first, and only Google it if that fails. I never got to the Google step.Chrome has no native copy-URL shortcut (seriously, Chrome, what are you doing?), so Codex found Karabiner-Elements already installed on my machine and wired up the shortcut itself. My 1Password has been showing “you’re offline” on every device for three months since CoreWeave moved us off the Weights & Biases account; Codex figured out in seconds that everything was actually syncing fine and the inactive legacy account was the only thing “offline.” Removing it fixed the whole thing. That is not an answer you find in a help center.It kept going. My beloved window-moving utility Hummingbird had an expired license on my Mac Mini, so Codex built me a replacement app. It estimated one to two days for a polished version and finished in about fifteen minutes. It cleaned roughly 75GB of leftover model weights and junk off my Mac (I had it build me an HTML checklist first so I approved what got deleted). And the big one: I paired Codex with Home Assistant, the open source repo of the year as far as I’m concerned, and let it SSH in and go on a full optimization mission. Updates, error triage, cleanup, new connectors. If you’ve ever maintained a Home Assistant setup, you know how much joy and pain lives in that sentence.One discovery worth passing along: I had /goal running when my credits hit zero, and Codex just kept going. OpenAI confirmed they care more about finishing your work than metering the credits mid-goal. Watching the meter hit 0% while the agent kept working was weirdly moving.Thanks for reading ThursdAI - Highest signal weekly AI news show! This post is public so feel free to share it.Fable Max built my family’s vacationWe all Fable-maxed when we thought Anthropic was going to take it away, and I pointed mine at this trip. It planned the whole thing, then built a b