YHK - yet another hacker news clone

After yesterday outage is the new Opus 5.5 load-bearing?

I hope this actually fixes the terrible writing style of Opus 5

Just post the bloody content. This UI/scrolling thing is horrific.

This makes Fable not really make any sense?

> Opus 5.5 communicates more naturally than prior models. Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5.

Sounds like they noticed the complaints. I'm curious to see what LLM-isms this one may have.

Dupe: https://news.ycombinator.com/item?id=49803863 (or vice versa)

What happened to "slowing down"?

The test they performed to port HAProxy from C to Rust is crazy.

Dupe: https://news.ycombinator.com/item?id=49803892

So we skipped 5.1, 5.2, 5.3, and 5.4: we really are plateauing

At this point I'm convinced they are skipping numbers so soon they will be at or ahead of OpenAI's numbering scheme.

Is the Xbox 360 (Xbox 2) vs PS3 debacle all over again.

As long as it's not as verbose as Opus 5, I am quite happy with a better version that's also less expensive. I will test it tonight. Grok 4.7 was horrible, and for mundane tasks I am relying on DeepSeek Flash 4.1 with great success using OpenCode.

The whole thing reminds me of the Apple feature flag story[1] from a generation ago.

[1] - https://news.ycombinator.com/item?id=6372466

Wow! Though need to see its token efficiency to better assess. Been hearing rumors it generates much more output tokens per task.

Interestingly they've changed their approach to usage resets for this release - with previous releases I've had my usage instantly reset, but now in the Claude app I've got a 'Reset for free' button that expires Oct 22, which seems to effectively be a whole new usage window I can activate whenever's convenient

Masterpiece by openai to call their model '6', this model feels already behind

System card: https://www-cdn.anthropic.com/fc1b44717c85dc068bc6ba50242199...

> We see signs that Opus 5.5 often suspects it is being evaluated, which challenges our ability to assess how it will act in the vast variety of real-world settings it is deployed in.

We can't test it properly because it knows it's being tested.

“It performs at the level of Claude Fable 5.1 on most work and costs 40% less to run than Opus 5.”

They write that at the top, but then on benchmarks, it beats literally every other model, including Fable and Astra?

So it beats Fable 5.1, by quite a bit, on every metric? Interesting.

Might have to use my $20 Claude sub some more. I was moving away from it to a $100 OpenAI one to avoid the Claudese and poor token efficiency of Opus 5, given that I couldn't use Fable 5.1 with my tier, but this is worth trying out.

Anthropic models are ridiculously expensive. I've stopped using any of their models months ago.

> It performs at the level of Claude Fable 5.1 on most work and costs 40% less to run than Opus 5.

> Input and output tokens are $4 and $20 per million, 20% less than Opus 5. Cache reads (which make up the majority of agentic and coding work costs) are $0.20 per million tokens, 60% less than Opus 5. Opus 5.5 also generates output more than 30% faster than Opus 5.

Better than Fable, cheaper than even the last Opus. I use Opus as my main driver so this is very exciting!

I'm more excited by the Haiku 5.5 announcement buried in this post. I'm wondering if we will finally get a decently capable fast model.

They mention "the first model in our new Claude 5.5 family". Obviously that means Fable 5.5, but hopefully also a usable update to Sonnet and Haiku. Sonnet 5 hasn't really had a place in the line up for anyone I feel.

Maybe Anthropic finally felt the pressure from MiMo, DeepSeek, GLM Flash and Luna.

$0.20 vs the old $0.5 cache read is pretty much 60% off

> “Verbose, hard-to-follow output has been my biggest frustration with frontier models, and Claude Opus 5.5 fixes it

God I hope so

Astra is just so good. And the ChatGPT subscription lets me use my own harness, so I can hook it up to exe.dev.

I’ll be going about my day, have a random idea, launch a microvm on exe.dev with a prompt of my idea, and get a working thing a few minutes later.

I don’t know how much better a model would have to be to get me to move off OpenAI at this point, but doing just a little bit better in terminal bench 4 isn’t it. It would have to be a difference in kind, like opening up the harness restrictions, or privacy guarantees (comparable to offline models).

Edit to address questions below:

ChatGPT supports oauth login.

Exe.dev has it built in. IIRC, pi also has it built in via /login.

  Opus 5.5 Medium = $1.34
  GPT-6-Astra High = $1.76

  Opus 5.5 High = $1.82
  GPT-6-Astra High = $1.76

Let's see how much they benchmaxxed their model!

Input $4/MTok and output $20/MTok is a welcome surprise. Cheaper than Opus 5/4.8, Astra 6, Fable 5.

Why would anyone reward bad behavior?

I use the other 50% of my $200/mo Claude subscription by having Fable run Opus subagents for a lot of work. That way I don't have to deal with Opus directly.

I think this release is really going to give them a hard time selling Fable:

> On our benchmarks, Claude Opus 5.5 leads in agentic coding, computer use, and knowledge work. That said, at these levels of capability we’ve found that benchmark margins have become a less reliable guide to real-world differences. In our own use, the gap between Opus 5.5 and Claude Fable 5.1 is narrower than these scores suggest.

In general, "benchmark margins have become a less reliable guide to real-world differences" sounds like a big problem. It was certainly the biggest problem with the previous generation of Claude models for a different reason, because the non-code output was nonsensical, and that is not being benchmarked at the moment. But I'm not sure what to make of this admission.

    "benchmark margins have become a less 
    reliable guide to real-world differences" 
    sounds like a big problem.

Looks like Anthropic is starting to give bank reset as well:

> Reset for free: Get extra wiggle room to explore Opus 5.5. Expires Oct 22.

Finally that price drop

   Prices per 1M tokens     Claude Opus 5.5    Claude Opus 5
   Cache reads              $0.20              $0.50
   Input tokens             $4                 $5
   Output tokens            $20                $25
   Cache writes             $5                 $6.25

Opus 5 is the model with highest spend on openrouter (https://openrouter.ai/rankings#task-spend) and it seems plausible that Opus 5 is/was the highest spend model in the world, and certainly Anthropic's biggest moneymaker.

If you are forced to reduce price despite raising capabilities, that certainly tells something about the market, and potentially about Anthropic future profitability too, since this model is their biggest topline contributor

> It’s good at finding and fixing inefficiencies in software

Holy shit! Its happening!

Now if we can the AI to understand this *implicitly* so that it doesn't need to be stated upfront, we might be able to undo years of "premature optimization is the root of all evil".

>Because Opus 5.5 is comparable to Claude Mythos 5.1 in biology and cybersecurity, we’re deploying it with safeguards similar to those on Claude Fable 5.1. Vetted organizations can apply today to our Life Sciences Verification Program to use Opus 5.5 for biology research. In the coming weeks we will also be expanding access to our Cyber Verification Program, and verified cybersecurity practitioners will be able to use Opus 5.5 for their work.

Ah, they're spreading their limits to all their models it seems. Definitely not a good thing long term in my opinion.

Throwaway accounts posting after a few minutes some anthropic or another ai lab.

Infomercial at its best.

No wonder we are hammered with ai announcements.

With the performance gains they're claiming, I wonder if they implemented the Casual Encoder-Decoder technology from DeepSeek 4.1's paper.

I could see them accomplishing it and seeing gains like this in roughly the correct timeframe, and when I heard about that development I assumed the frontiers would probably jump on it.

How it works: https://miraflow.ai/blog/deepseek-v4-1-flash-causal-encoder-...

> Claude Opus 5.5 is our first release since we called for pacing the frontier.

Interesting how the very first line is used to remind the reader of their call to pace the frontier just last week, and everything else after that line is to demonstrate with very specific numbers how they absolutely are not pacing.

Finally, it seems like a good time to do some 'load-bearing' work on my project for a while

My 20x plan was set to end tomorrow. The writing style and insistence on word vomit just became too annoying. Is Opus 5.5 worth sticking around for ?

> For users with cybersecurity use cases that may be blocked by our cyber safeguards, we recommend accessing our models with reduced cyber blocking classifiers via our Cyber Verification Program. Claude Opus 5.5 will be available through this program in the near future.

Anthropic has used "in the near future" for Mythos-class models too, but CVP is still Opus 5 only.

Why even have the program designed for trusted access to cyber capabilities if you're not providing access to cyber capable models via the program?

> Claude Sonnet 5.5 and Claude Haiku 5.5 will follow in the coming weeks, with many of the same improvements to performance, efficiency, and safety.

Nice. I was starting to think Haiku was going to be abandoned.

> Because Opus 5.5 is comparable to Claude Mythos 5.1 in biology and cybersecurity, we’re deploying it with safeguards similar to those on Claude Fable 5.1

Great so good luck using this for any low-level embedded or operating system development (unless you really, really like Opus 4.8 and want to be greeted by its familiar face after a few minutes of work!)

I don't yet have any reason to leave Haiku 4.5 and switch to Opus 5.5.

> Claude Sonnet 5.5 and Claude Haiku 5.5 will follow in the coming weeks, with many of the same improvements to performance, efficiency, and safety.

Nice. I was starting to think that Haiku got abandoned.

I knew it. https://news.ycombinator.com/item?id=49801266

How do I get access to that reset? I can’t find it in my app.

Great that they listened! The improvement in communication style looks fantastic. Opus 5 was insufferable and I was on the verge of cancelling my subscription.

>Distillation attacks, in which attackers use thousands of fake accounts to extract a model’s capabilities at industrial scale, create safety and national security risks. Distillation allows bad actors to create highly capable models without the safeguards we build into Claude.

Maybe its a bit tiresome to read another comment of the form "what about your large scale distillation attack on the Internet", but this statement really just pisses me off. How very insincere in the most aggravating way.

Current models, especially Opus are almost unusable because they don’t respect instructions and their responses are infuriating. They are clearly designed for token consumption. I find myself wasting a lot of time just asking it to shorten or simplify its responses. I’ll give this new model a go, but I’m not holding my breath because the last model release was supposed to fix the very same issues and it didn’t.

Enjoy it for the next 2 weeks until its silently quanted to 4.8 level

> We’ve made major improvements to the way Opus 5.5 writes and communicates, one of the most common areas of feedback we heard about Opus 5. Its messages are much easier to understand at a glance, which testers said helped during long working sessions.

Thank you.

Opus 5.1 came out about a month ago, what gives?

Great. Now let me use the subscription outside Claude Code.

So it Opus performs as well as Fable what is then the selling point of Fable?

All of this starts to feel more like a drug dealer selling their newest stuff.

In two weeks we probaly get Fable 5.2 with “groundbreaking” improvements, then Astra x+1 etc and then the cycle starts again.

And on the way I always have to check my tooling and need to adjust things to get max results.

What I'm mostly interest in is the Communication section. Opus 5 was so convoluted in the way of answering that was really frustrating me.

Instead of instilling confidence, it was overwhelming. Not sure if I'm the only one.

Funny how they talk so much about safety when most people don’t give a hoot about it, and actually have quite the opposite reaction

They purport 40% drop in costs due to lower token pricing (presumably aimed at winning back the many of us that switched providers in discovering Opus 5 unusable) and improved token efficiency.

Notes on communication:

"Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5"

and

"We’ve made major improvements to the way Opus 5.5 writes and communicates, one of the most common areas of feedback we heard about Opus 5."

and

"In our own use, this has made Opus 5.5’s work easier to follow and check—which is a safety benefit as well as a practical one."

I realize it is corporate communications but "most common areas of feedback" and is a bit sterile. If the company wants authenticity and trust its easy to say that they found it hard to follow. And that it did not meet a quality bar they generally expect from their releases.

If this is not true, that it Opus 5 output was generally acceptable and we might see something like that again, that is an important consideration for potential customers or investors.

> Distillation attacks, in which attackers use thousands of fake accounts to extract a model’s capabilities at industrial scale, create safety and national security risks. Distillation allows bad actors to create highly capable models without the safeguards we build into Claude. Our September 2026 threat intelligence report details the illicit distillation activity we’ve detected and disrupted so far.

Such a negative tone they put on this. Distillation is amazing, because it means anthropic and openai fail to keep a monopoly. Who even are they who claim it's unethical? If it is truly unethical, then so is the mass data scraping they do on my personal website on a regular basis (without my consent), and all the unauthorized use of content produced by authors, blog writers, wikipedia contributors, and creators everywhere. If it is truly unethical, then anthropic, openai, meta, google... all these companies should have deleted their LLMs long ago. This wording disgusts me.

Heck, it would be amazing if we had more models without guardrails - some of the models that are produced via heretic[1] are actually quite nice to use - in particular, I've enjoyed investigating Chinese censorship by interacting with an abliterated model of Qwen3.8-27b. If security is really a concern, then secure your systems - don't attempt to dumb-down the tools we use. If someone breaks your window, then they are responsible, not the hammer they use to do so.

[1]: https://github.com/p-e-w/heretic

I found myself going back to Fable over and over again. At this point, I’m not sure if I’m just used to its style or it is truly more capable.

I tried Opus 5 and Astra.

It crushes Fable on benchmarks and even in the blogs "real-world" studies. But... they are communicating like it ~sometimes~ provides Fable intelligence?

A bit confusing, otherwise I would assume this is a complete replacement for Fable across the board??

I have just switched to 5.5. First mistake was stale environment variable, didn't realize it was replaced, "oh my memory had stall data" and that's it. Second one, a powershell command had the wrong syntax. Great for my first two prompts.

I'm glad they specifically called out the prose issue, I was always pinned to Fable 5.1 because I wanted to avoid the unreadableness of other Anthropic models.

> In the coming weeks we will also be expanding access to our Cyber Verification Program, and verified cybersecurity practitioners will be able to use Opus 5.5 for their work.

I was accepted into the CVP a little while ago. Does this mean I'll need to apply again?

ooh exaggerated film grain

I dare anyone to convince me the benchmarks are not meaningless.

Wdym Opus 5.5 scores 14.7% higher than GPT Astra for Terminal Bench 4.0?

How would this alleged difference (most likely bs) actually show up in reality?

GPT Astra was literally the best model in the world by a margin until 1 hour ago or so.

Finally confirmation that Haiku was not forgotten and will be coming soon, althouhg I find it quite interesting they skipped 5 and directly skip to 5.5 with all models, including Sonnet which is not super old. I suspect they found something breaking that allows to release this. Recently they struggled with keeping up a 50 % weekly limit increase and now they're putting out 30-40% faster and cheaper models even faster, with much more better benchmarks, a limt reset command and five hour limit increase. It seems more like the opposite and as if they never struggled, thus, I very much believe they found something very effective and new.

But have they made it any better at communicating clearly? I cancelled my personal subscription because Opus is so painful to read.

I'll have to try 5.5 on my work's Cursor account. If they really solved the communication issues, I might consider moving my personal account from Codex back to Claude Code.

> Communication. Opus 5.5 communicates more naturally than prior models. Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5. It puts the most important information up front, and its style makes it a better work partner over long sessions. As one early tester put it, “it writes the way I do.” In our own use, this has made Opus 5.5’s work easier to follow and check—which is a safety benefit as well as a practical one.

I think this is what I'm most interested in. I mostly moved to Astra because I just can't work all day with the Claude Opus 5/Fable writing style. I don't think Astra is a better model, but it's the first OpenAI one that seemed good enough to me. Definitely keen to try Opus 5.5 and see if this claim is real.

It'd better be good, I'm so tired of the shenanigans

So is it cheaper? Are we AGI yet? Am I left behind? I didn't have patience for the intro animation on the website... maybe one day, Claude Code will understand accessibility but that day is not today.

It's awesome that the apt packages for claude and claude-code are out right now. I can test-drive Opus 5.5 right away. Very cool, Anthropic.

Excellent, maybe Anthropic can use it to fix Claude Code Desktop kicking me back to login every week or so, and forgetting whole state (opened windows = the only way of managing active working set) when I sign back in, if it's that good.

Seriously, both flagship GUI apps (OpenAI and Anthropic) are a full of glaring UX issues (for ChatGPT it's not naming their windows, so window switcher has 10 entries of "ChatGPT" and you can cycle them all to find the one you want).

So... why would you use Fable now?

I don't care how good their models get, I won't sign up for one of their plans until they define "X" in their pricing. 5X of this plan, 20X of that plan means nothing when they never tell you what "X" is.

Maybe this model can finally figure it out for them.

Here are pelicans for thinking levels low, medium, high, and xhigh: https://tools.simonwillison.net/markdown-svg-renderer?url=ht...

All four levels have a correctly shaped bicycle frame. The differences between the pelicans aren't huge, but the xhigh one has a better beak.

I haven't managed to get one for level "max" yet, it hit the limit of 128,000 cap for output tokens while it was still reasoning about the question!

Max started its thinking trace like this:

> This is a classic test request, so I want to plan out a well-composed pelican with its distinctive beak and pouch riding a bicycle with proper wheels, frame, and pedals, set against a simple sky and ground backdrop.

So that failed attempt on max cost me $2.56.

I ran this using my llm-anthropic plugin:

  uv tool install llm
  llm install llm-anthropic --upgrade
  llm keys set anthropic
  # paste key here

  llm -m claude-opus-5.5 -o thinking_effort low "Generate an SVG of a pelican riding a bicycle"

  # Then to save the markdown logs
  llm logs -cu > logs-with-usage.md

I get this in my claude.ai usage:

Resets Get extra wiggle room to explore Opus 5.5. Expires Oct 22.

What the hell does this mean? There are weekly "resets" anyways. And there will be 4 of them before Oct 22.

is OPUS 5.5 still not reading CLAUDE.md, failing to follow told tasks, inventing and hallucionating, just refusing to read files ("read the whole file" -> read 2-lines -> infere its wrong -> destroy the codebase), needing constant babysitting just because its so UTTERLY DUMB! i cant imagine going back to OPUS 5 - i'll rather jump out of the window as to use it EVER AGAIN!!

Hopefully OpenAI throws us some more usage resets now.

"Where Opus 5.5’s advantage is very clear is efficiency."

Not efficiency in writing, clearly.

Image->HTML tests:

Design: https://image.non.io/78795662-8bfc-4e14-8d72-3738392aa6b3.we...

Opus 5.5's output: https://html.non.io/annui-opus/

Overall it follows image designs quite well, but it did ignore asks to animate page transitions. Additionally it's the least performant of the ones I've built with Astra/Grok/MiMo, despite using a lot of the same code. I'd rate it just below Astra in capability, but still solidly second place.

For comparison with other drops this week + current #1:

Astra: https://html.non.io/annui/

MiMo: https://html.non.io/annui-mimo/

Grok 4.7: https://html.non.io/Annui-grok/

> Opus 5.5 communicates more naturally than prior models. Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5.

Thanks God. Opus 5 was a massive regression compared to Opus 4.8. People were spending tokens on fixing Opus-isms rather than actually doing work.

It seems context length has completely fallen out of the discussion since we hit 1M, is that just going to be what it is now?

Cost to Run Artificial Analysis Intelligence Index is higher than previous Opus, so still not cheaper

> Opus 5.5 (1M context)'s safeguards flagged this session. You may be seeing this for the first time on an Opus model: Opus 5.5 (1M context) is more capable and has stronger safeguards as a result, which can sometimes flag non-cybersecurity work. We're improving these safeguards to reduce the amount of incorrectly flagged messages. Opus 4.8 is answering instead, or you can edit and retry with Opus 5.5 (1M context).

Yay, yet another model I can't use for anything interesting, even with CVP.

wow its really smarter than opus?

It's great that we are finally getting bankable rate limit resets for subscription users. According to another comment here they apparently last a month.

I'm assuming that subscription usage limit is increased in line with the price decrease on the base model and that it's in line with the model's API price drop. Still a good change.

This is a breath of fresh air on how they treat subscription customers. Hoping they keep this up.

I spent about $5 per sentence in my resume using Fable 5.1 (High) to verify accuracy, inconsistency, and edit.

Opus 5.5 (med, as it's better than F5.1 high per graph in the article) used $2.2 and caught errors that Fable 5.1 missed.

Try Opus 5.5, cheaper, faster, and more intelligent for those prepping for interviews.

I am pacing my apple pie consumption … :)

Opus 5.5 is now the recommended model in Claude Code's model picker, which is quite a claim, given how they struggled with capacity.

I'm only interested in the Opus series, if they fixed the talking issues.

> Because Opus 5.5 is comparable to Claude Mythos 5.1 in biology and cybersecurity, we’re deploying it with safeguards similar to those on Claude Fable 5.1.

Considering fable gives me a refusal at least once a day on my very mundane reasonable requests (in a funny example - one of the subagents suggested bypassing the rate limit for running a report inside my own cluster and that caused a refusal) and my only solution is to switch to opus - seems like my next step will be switching to Astra or K3/GLM

GPT Sol 6 has also released today, but no official blog announcement yet

https://www.reddit.com/r/codex/comments/1wnggya/gpt_6_droppe...

Just updated KillSwitch-Bench with this new model: https://bench.killswitch-lang.org/

It does perform slightly worse than Opus 5, but it is significantly cheaper and faster.

   > Opus 5.5 communicates more naturally than prior models. Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5

Big, if true.

METR: Is it safe? Has it escaped confinement?

Ants: It's a good model, sir!

I noticed a big speedup in Opus 5 on Max x20 since about 10 days ago, and I feel like the model has been performing better.

It would be great to know if this was Opus 5.5 or a lesser incremental improvement, as otherwise it's difficult to judge whether Opus 5.5 is expected to be a big improvement.

It's frustrating that there isn't more transparency here.

> cyber security and life sciences verification programs

chinese models can't come soon enough

we're already getting enshittification

So is this AGI+ now?

So much for pacing the frontier

> Opus 5.5 is the first Opus model to launch with a similar class of safeguards to Fable 5.1 on cybersecurity, biology, and distillation, all of which fall back to another model transparently.

This is where Chinese models are going to eat Anthropic's lunch.

What I don't get is, why would we still use Fable now? What is its reason for existing? If it is more intelligent and cheaper that is. Why are they advertising it as the model to use for when you really have to think when their benchmarks show Opus 5.5 is better at everything?

Quick test for my gamedev project: It feels like using Fable, but faster, and obviously wayy cheaper token-wise.

Has oneshot all of the quite complex bugs / debugging tasks I gave to it which I know opus 5.0 would've struggled with

Welp, it's now blocking me from doing extraordinarily mundane tasks because of "safety". I've been an Opus fan for a long time, but this instantly made me cancel my subscription and move to OpenAI (which I also assume will screw me soon enough). Chinese models are almost there for my needs, and I can't wait to switch to them and never look back.

When using max effort, I run into context compaction quite a lot. I haven't seen any increase in context window size at all over the past half year (stuck at 1M).

Are the frontier labs even working on this problem?