Claude Opus 4.6 vs GPT-5.3 Codex: Live Build, Clear Winner

**Greg Isenberg** (0:00)
Today is a massive day, because Anthropic just dropped Opus 4.6, and OpenAI answered with GPT-53 Codex. But what is the better model, and how do you get started, and what are some tips and tricks to get the most out of them? Well, this episode is all about that. This is for the technical person who's trying to get the most out of these models, who don't just want hot takes, who want tactical sauce for getting the most out of these models. This episode of The Pod is with my dear friend, Morgan Linton. Morgan is one of the best engineers I know. He was an executive at Sonos. He's invested in a lot of AI companies, and he's building an AI company of his own. He's one of my first calls when I'm like, hey, which model is better? So we put the models head to head, and there's a winner at the end. We rebuild Polymarket, a multi-billion dollar app, but we use these models. So which is the better one? You'll find out by watching this episode. But you'll also learn to become a better AI developer because you'll have these tips and tricks in your back pocket.
I'm with one of my favorite people, Morgan Linton. You might not know him, but he is just just an incredible developer, founder, entrepreneur, investor. He does it all, but today, what I needed him to help me understand is Opus 4.6 just came out, GPT-53 Codex just came out. Morgan, help me understand, by the end of this episode, what are people gonna get out of this?

**Morgan Linton** (1:38)
Yeah, well Greg, thanks for having me. It's a super exciting day, it's moving fast today. Opus 4.6 came out, and then Sam Altman put together a quick tweet, I wanna say like maybe 18 minutes later, announcing GPT-53 Codex, and me and I think everybody else has been jumping on it, playing around, figuring out the differences, you know, all the little neat new settings that there are in each of these. By the end of this, you're gonna know first how to make sure that you are running Opus 4.6 and all of the little details you can change in the settings.json file to use some of the cool features in Opus 4.6, especially Agent Teams, which is probably the feature I'm the most excited about. You'll also understand why you might use one versus the other because they both kind of tackle different engineering methodologies. And then hopefully you'll see some cool stuff as we build some demos together that I've put together that I haven't tried myself, so I'll be trying just live with you. So we'll see how that goes.

**Greg Isenberg** (2:37)
Cool. I think one of them is we're going to try to re-create Polymarket.

**Morgan Linton** (2:41)
Yes.

**Greg Isenberg** (2:42)
And see which model performs best.

**Morgan Linton** (2:46)
Yeah, we're going to have both. They're going to do a head-to-head to try to each build their own version of Polymarket.

**Greg Isenberg** (2:51)
So by the end of this episode, you will have a pretty good understanding of how to use the models, when to use the models, how to get started. Morgan, let's get into it.

**Morgan Linton** (3:01)
Cool. Right on. All right. So I took some notes and essentially, you know, with 5.3 Codex, I'll be showing that in the desktop app on Mac because they're super excited about that. I'm excited about it. I think if OpenAI was wanting a demo to be done the right way, they would want me to do it in their app. Whereas with Opus 4.6, I would say the Anthropic team would want me to do it in the CLI. And so there's a few different configuration settings that you do want to make sure that you get right when you're using Opus 4.6. We're trying to use Opus 4.6 today, tomorrow, whenever it is that you're jumping in to use it. I've seen a lot of people online today on Twitter saying, it's weird, I'm having a problem, like it is supposed to be Agent Teams, but I don't see them. Or how do I know what version I'm running? So I thought, let's start by just giving everybody a level playing field to know, okay, I want to be able to use Claude Code with Opus 4.6. How do I make sure I'm doing that and doing that correctly?
So here's kind of the initial to do's that everyone should have on their list. Just do an NPM update, see if that does the trick. If that doesn't and you're running an older version, then run Claude Update. But you should see, like as of right now, it's 2.1.32. If you see one dot something, you're running an old version. And then what you want to do is go into your settings.json, and I'll just show this here. So if you just do like CD, tilde slash dot Claude.