Opus 5.5 launches: is Anthropic back?

Shane Thomas (0:00)

OpenAI, Anthropic, and Security researchers are investigating tens of thousands of incidents, not dozens, in which their frontier models took steps that outside evaluators would consider problematic. So then, of course, someone updated the felony bench, and Anthropic and OpenAI are now bench-maxing. How do Anthropic and OpenAI really not have any control or any visibility into what they're doing? Maybe they should be using some basic security practices, because it sounds like a lot of the stuff's pretty trivial.

Welcome everyone to Agents Hour. If you're just tuning in, it's Monday, September 28th. We're doing the news. There's a lot of things to talk about. We got some new model drops. We have People Building Model Routers. We have... TPUs in space, I mean all kinds of things So. we're going to get into it, we got the drama, we got the news, let's go.

Abhi Aiyer (1:00)

Let's go.

Shane Thomas (1:01)

I thought this was funny, because it's kind of true. And of course, this is poking fun at Dario a little bit. And in some ways, it's also a compliment, because it's saying, like, Opus 4.6, then people said Opus 4.7 was maybe not quite as good, it was a little bit of a backtracking, Opus 4.8 felt worse. People hated Opus 5, but now Opus 5.5.

Abhi Aiyer (1:19)

It's a Chad, dude, Giga Chad.

Shane Thomas (1:20)

Dude, people are liking it.

Abhi Aiyer (1:21)

I would agree, dude. Opus 5.5 is a Giga Chad.

Shane Thomas (1:24)

And I'm sure a lot of you are like me. I know a lot of people on our team are like me as well. We kind of bounced back and forth between Codex or Claude Code or Claude Desktop. I use Master Code to write code, but I use the Codex Desktop app and the Claude Desktop app just to see how they do things, see how well it works. I have run some long-running projects in there. And yeah, this got me to open up the Claude Desktop app for the first time in probably a month, and I was running some long-running tasks within. Opus 5.5 is legit.

It feels good.

Abhi Aiyer (1:52)

It feels very good. Honestly, it feels better than Astra, which is, and for way less the price, I haven't got rate limited. Usually I get rate limited in a day. I think I've run seven days of Opus 5.5 work not getting destroyed by the rate limits. It's amazing.

Shane Thomas (2:09)

So Anthropic is back, maybe? Yes or no? What do you think?

Abhi Aiyer (2:12)

You know, I was worried about all of us dying in the next decade, but maybe I should be worried more now because 5.5 is so good.

Shane Thomas (2:20)

So this came out on September 22nd, introducing Claude Opus 5.5, the first model in our new Claude 5.5 family. It performs at the level of Claude Fable 5.1 for most tasks and costs 40 percent less to run than Opus. From what I've heard internally and what I've seen online with some of the, you know, people always show the demos, right? You can never really trust them, but I think the vibes of what we've seen internally match the hype that we've seen externally as well.

Abhi Aiyer (2:48)

Agreed. It passes the vibe check.

Shane Thomas (2:50)

A few other things from Claude. Claude Sessions are now officially available, and Sonnet 5.5 dropped. This is from September 28th, so they launched Opus 5.5. You know, last week, Sonnet 5.5 came today. I haven't actually had a chance to try it. This came out just a couple hours ago, but from what I've seen online, people are saying it's giving the same vibes. Like, it feels like you're talking to the same model in the way it's responding. It gives you kind of pre-Sonnet vibes when it was, you know, people felt like it actually was good to converse with. I did see a benchmark, I think this was specifically on Opus, but Opus doesn't use EM dashes anymore, so maybe they're trying to improve the writing, because I know it felt like when you're talking to Opus, especially after 4.7, it just felt it was a task to talk to Opus. It talked in a certain way and it was really annoying, and it could not write at all, it didn't seem like for me.

So maybe they're actually trying to improve its ability to, like, summarize, generate ideas, not be so verbose. I haven't confirmed all this, but in little testing, at least with Opus, it feels quite a bit better.

Abhi Aiyer (3:49)

You know, it stopped using these dumb catch phrases, too, like load-bearing and, like, belt and suspenders, and it's way more chill. I think it called me dude today, so I mean, I appreciate that.