Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Claude Fable 5.1 and Claude Mythos 5.1

anthropic.com

Post reply on HN
Print view View original

161–170 of 1001 posts

Re: Claude Fable 5.1 and Claude Mythos 5.1

#161

Post by codexon »

Avicebron wrote: post #29
scronkfinkle wrote: post #3

Has anyone been able to get anything substantial done with Fable in the first place? I more or less had totally given up on using it since the alignment checks were so sensitive that it pretty much always threw me back to Opus.

No, almost anything related to my job is flagged for "cyber" and my company currently has no plan to try and enroll into mythos. I'm not sure if anyone has been able to enroll solo. It did help with some worldbuilding for my book (it wasn't incredible which gives me some hope for writers). So far opus 4.8 is the most reasonable model.

I heard the only way you are going to get into the CVP program is if you have public CVEs. Doesn't seem to matter if you are in a company account or not according to people that are supposedly in the program.

Re: Claude Fable 5.1 and Claude Mythos 5.1

#162

Post by marcelo-earth »

Someone1234 wrote: post #92
tarr11 wrote: post #35

“ Claude Fable 5.1's writing is generally a step up from earlier Claude models, with fewer stock phrases and less unexplained jargon. In some cases, though, its prose is denser than Claude Fable 5's: sentences run longer and there are fewer paragraph breaks.” I cancelled my pro max Claude subscription last week; codex is much more succinct. I am curious if this is getting better. I don’t think Anthropic realizes that…

One thing I've noticed and HATE, is that when you increase thinking-effort, that seemingly increases response-length. Meaning that X.High is longer than High, which is longer than Medium, etc. Which is kind of the inverse of how people work; a really smart person can condense difficult ideas into simple[r] terms. Whereas people who struggle speak a lot but say very little. High/X.High do seem to deliver better qualit…

I hate this too, I had to switch to Codex, because the skill to force Claude Code not to think too much about very, very basic things no longer worked

Re: Claude Fable 5.1 and Claude Mythos 5.1

#164

Post by darepublic »

belval wrote: post #86
felixrieseberg wrote: post #69

(I work at Anthropic) Beyond all the benchmarks, I think Fable 5.1 is a big improvement in writing style. It sounds a lot less stereotypically like other Claude models, has (imho) a much more natural style, and responds to my style instructions more reliably. More work to be done (and we will!) but reading better prose makes me so much happier. Another point I expect not to get much attention until it all happens at…

As a fervent Claude Code user who made the switch to GPT 5.6 Sol over Opus 5 over hard-to-read prose this makes me happy. I love your product but the current models are very hard to work with if you need to do a lot of context switching. Brevity is key.

Also a codex user but for me brevity is not it's strong suit. I basically have to give it bigger tasks than I am used to to warrant the time it takes to complete. I feel whatever context the tooling adds can also be problematic

Re: Claude Fable 5.1 and Claude Mythos 5.1

#165

Post by zahlman »

velcrovan wrote: post #121
felixrieseberg wrote: post #69

(I work at Anthropic) Beyond all the benchmarks, I think Fable 5.1 is a big improvement in writing style. It sounds a lot less stereotypically like other Claude models, has (imho) a much more natural style, and responds to my style instructions more reliably. More work to be done (and we will!) but reading better prose makes me so much happier. Another point I expect not to get much attention until it all happens at…

I have a pet theory that the Opus prose style/smell we all have grown weary of is due at least in part to the models writing more for themselves and each other than for humans. They're packing lots of signal into fewer words and they don't care if it sounds cringe because it works better as glue in long-running tasks. I'm also thinking of the 2017 novel "Void Star" where AIs who operate everything have long since lef…

> They're packing lots of signal into fewer words

There's a huge difference between the kind of prose you see in final output vs CoT windows. The final output is very much not what I'd call "packing lots of signal into fewer words" (aside perhaps from "Claude-isms" being easy enough to scan for if for some reason you actually wanted to scan for them, which other agents might want to for all I know); and if agents are writing for each other then presumably they could stick to CoT-speak (unless it's a distillation risk?).

Re: Claude Fable 5.1 and Claude Mythos 5.1

#167

Post by vablings »

prettyblocks wrote: post #11
scronkfinkle wrote: post #3

Has anyone been able to get anything substantial done with Fable in the first place? I more or less had totally given up on using it since the alignment checks were so sensitive that it pretty much always threw me back to Opus.

It's probably a good model for folks doing basic software stuff, or humanities related tasks, but I work in cybersecurity on the defense/detections side and I haven't been able to use it for anything even with being in the CVP. It downgrades to Opus every time.

I have been running Fable with Binary Ninja MCP. It will reverse engineer a binary in a lot of detail if you give it mild direction and I haven't had it flag. I think it assumes since I have a valid binja license I must be responsible lol.

I do think probably ralph looping a binary locally first is going to be best to get 100% recovery of types and function behaviors then letting a smarter model churn the final steps.

Re: Claude Fable 5.1 and Claude Mythos 5.1

#168

Post by adamanonymous »

CamperBob2 wrote: post #123
precision1k wrote: post #87

Earlier quoted context omitted.

I've developed a habit of adding into my prompts "please keep your response concise and succinct" or "I'm trying to cram, please only provide the minimum level of technical detail necessary to understand this topic" I find it helps immensely but it'd be nice if I didn't have to do that.

I don't understand that complaint, although it seems to be a common one. The whole problem with the way models talk nowadays is that they are succinct to a fault, going to the extent of coining new buzzwords and misusing existing ones. What I want to see is a shift towards plain language.

I’ve had good results adding “also I’m a baby” to the end of all my requests for explanations

Re: Claude Fable 5.1 and Claude Mythos 5.1

#169

Post by hungryhobbit »

ayhanfuat wrote: post #100

I noticed they reset the usage and I was kind of happy because this week it was using my quota much faster; I assumed they fixed that. Apparently it is for the celebration of 5.1?

They dropped your usage limit by 17% this week .. They claimed to "raise" it, because they did ... while also removing the temporary increase they applied for a few weeks ... but the net effect is you can use 17% less than you could last week.

On top of that, recent versions of Claude had a ton of tools added, and all those tools use up significantly more context/usage than before, so the moment you open a Claude session you are already using a lot more (I forget how much more) usage ... just to do the same exact thing you did last week.

Re: Claude Fable 5.1 and Claude Mythos 5.1

#170

Post by unglaublich »

dabinat wrote: post #147

> This required us to add a watermark—a numerical way of determining the likelihood that Claude was involved in writing a piece of text—to the outputs of models released after August 2, 2026. As we recently explained, this watermark is invisible to anyone who does not have the detection API. It has no practical impact on the quality or content of Claude’s outputs and contains no information about the user, their orga…

It does change the output, they never said it did not. They said it would not _noticeably_ affect performance.
Post reply on HN