[zarzavat]

Fable changes the game yet again, because it's API-only.

You're not likely to want to run Fable in a loop any more than you want to take a bunch of dollar bills and light them on fire. Every invocation of Fable has to be intentional, its context carefully managed. I feel like a babysitter.

[weird-eye-issue]

Compared to Opus 4.8 I really haven't been impressed

[danielbln]

And I've been quite impressed. Opus talks the talk, Fable walks the walk.

[stingraycharles]

I don’t understand what these comments add to the discussion, you always see these and it’s just noise at this point.

[danielbln]

They add nothing, meaningless anecdotes. I was kind of riffing on that.

[skrebbel]

Posting meaningless comments isn’t suddenly useful because you’re aware of it and “riffing on that”.

[danielbln]

And now you've added to the pile, congratulations.

[weird-eye-issue]

So you added BS, on purpose? There is nothing meaningless about anecdotes. The plural is data

[zarzavat]

Every metric becomes a target (Goodhart's law). Also, the plural of anecdote is not data.

The subjective anecdotes from HN users matter because they are not data and are much harder to game. Not impossible to game, always be aware of users with low karma, but more difficult than gaming a benchmark.

[stingraycharles]

But they’re not at all meaningful after a certain point, because they’re not even attempting to explain why it works well for them. It’s just noise like this.

[weird-eye-issue]

If somebody gives a longer explanation of why they like or dislike it that would just be more noise it doesn't really matter that much beyond their general opinion about it

[MomsAVoxell]

Yeah come on, if these endless dialectic statements get made, at least post more detailed information about how your position was attained.

[wwind123]

I make Claude, Codex and Gemini review each other's design plan and implementation. Each always found a lot of things the others missed...until Fable 5 came out. Whatever plan or code Fable 5 comes up with, now it's very hard for Codex and Gemini to find any serious hole in it.

[HappySweeney]

In my experience, audit findings decrease in frequency as a codebase matures. Was Fable doing greenfield work?

[wwind123]

It's not a brand new project, but a project I've been working on and off for the last half year. I was trying to add a major feature which required some big refactoring of the current structure of the code. With the previous models I'd expect many rounds of reviews and debates between the AI agents. But with Fable 5, there's basically no debate, Codex and Gemini basically approved immediately. :)

[phplovesong]

Damn that was a cringe comment

[vidarh]

I just had Fable run overnight in a loop, and it fixed ~150 compiler crashing bugs that Opus had kept deferring.

I wouldn't start with Fable - when I use burndown loops I tend to include instructions to document progress and set aside anything that turns out to be harder than expected, and solve the easy stuff first. When a model runs out of easy stuff and start struggling to make progress on what is left, I can let it keep churning on that - they get there eventually - or I can bump it up to a smarter model if one is available.

Opus had churned a week driving down spec failures, and did a great job. The 150 Fable took overnight were the ones Opus had kept putting aside.

[steveklabnik]

I had fable running in a loop overnight last night, finding bugs. It found a heap overflow. That triggered its safety guards, which converted the thing to opus, leaving opus to run the rest of the night, wasting my precious time with Fable.

Oh well, it was pretty funny, all things considered.

[vidarh]

That sucks - I've thankfully only had that happen once. Similar thing - I was testing my new X11 server, and it turns out that broken X11 packets can make Firefox crash, and I got a refusal on a sub-agent request Fable prompted to have an agent narrow down why.

[ianbutler]

There's a setting that stops fallback to Opus 4.8 if you would like to avoid that behavior.

Config -> Switch models when a message is flagged -> false

That should stop it entirely when a message is flagged and then you can come back without Opus having potentially made a mess.

[jacobgold]

Fable is supposed to return to subscription plans, unless I'm missing something: https://jacob.gold/posts/fable-5-removal-is-temporary/

  Anthropic says the change is about capacity and is temporary. In its launch announcement on June 9, 2026, it says:

  "After this point—when sufficient capacity allows us to do so—we aim to restore Fable 5 as a standard part of subscription plans. We intend to do this as quickly as we can."

[techpression]

They can’t keep their current models working on subscriptions[1], so we’ll see if this is marketing or not in the future. It’s smart to tease it no matter what, ”insert classic first hit is free drug reference”.

[1] https://status.claude.com

[zarzavat]

Apple claims their price increases are temporary too. I'll believe it when I see it. The capacity limitations are not going away any time soon.

[NitpickLawyer]

I agree with you that you don't need fable for everything, and you have to be careful on what you run it on. CRUD stuff, sure even the small models can do it. But there certainly are tasks that are very much suited for the absolute SotA and you'd leave money on the table by not using it. And how much a task is worth is dependant on how much it improves your bottom line. So the cost/token becomes largely irrelevant.

Let's take this [1] benchmark. A bit more context here [2].

Here models are asked to create kernels for running inference on models. This is a benchmark perfectly suited and highly relevant right now. It's easily verifiable, an active are of research, and the results are immediately useful.

Say you have 1 unit of compute, it costs 300k $ and serves 1x users. In comes Fable and after one session it gives you 30% speed-up on your 1 unit of compute. It can now serve 1.3x users. How much is that one session worth for you? How much is it worth for a company using 10 units? 100 units? How much is it worth for a hyper-scaler running 10.000 units? How much is it worth for a lab that trains the next frontier model and then serves it from 100.000 units? 30% is relative. And the cost for one session is really meaningless. It can cost 1m$ / session and it would still be worth it for someone.

[1] - https://kernelbench.com/mega

[2] - https://x.com/elliotarledge/status/2072814573753975266

[eru]

For now, I can use Fable from the web just fine.

> You're not likely to want to run Fable in a loop any more than you want to take a bunch of dollar bills and light them on fire. Every invocation of Fable has to be intentional, its context carefully managed.

Eh, that's just because it's the current frontier model. Give it a few weeks, and prices will drop.

[zarzavat]

API prices are the new normal. I doubt that prices will drop to the level of the subsidized subscriptions any time soon. Usage is growing exponentially but capacity cannot. There is no reason for them to waste their capacity on subscription users if they can sell that same capacity to API users.

Like with Uber and Lyft, the low prices were a fight for market share, but now they have successfully captured that market share the focus changes to balancing their books.

[eru]

I suspect subscriptions will stay. But you will see more and more roadblocks that the 'barely goes to the gym' user barely notices, but that the power user will chafe under.

I make that prediction, because the people who pay for subscriptions but only use them moderately at best are truly profitable.

[baq]

The $200 sub is the new free tier, has been for a while now.