Anthropic's Claude Fable 5.2 and Mythos 5.0 Are Impressive, But Be Prepared to Sell a Kidney to Afford Them

Anthropic released Claude Fable 5.2 and Mythos 5.2 on Monday, promising AI models that can turn a handful of instructions into working software, design physical objects, and tackle research problems that previously required teams of specialists.

You can now ask a chatbot to build the app you've always wanted. You may also need to sell a kidney to pay for it.

That's not because every prompt costs thousands of dollars. It's because Fable can keep working for days, writing code, testing it, and fixing its own mistakes while the meter keeps running.

Some users have already tested its capabilities, and they’ve been impressed—by the power, and the price.

AI YouTuber Matthew Berman put the model through a series of ambitious tests and described Fable 5.2 as the “best AI model” he's ever used. His projects included playable video games and a browser-based version of Microsoft Excel, complete with formulas and pivot tables.

One single level of Gears of War: E-Day-inspired level took 43 hours and 48 minutes of build time and processed 8.63 billion tokens—small chunks of information an AI reads and produces. The running API cost estimate, based on pay-as-you-go pricing for developers, had reached $14,710.

The Excel clone ran up an estimated $11,700 after discounts for cached inputs, or information the system can reuse instead of processing from scratch. Berman also showed a Fall Guys-style game that consumed more than 9 billion tokens over 71 hours, equivalent to roughly $13,000.

Those are estimated API costs, and the projects weren't flawless: Berman reported awkward animations, bugs, and features that still needed testing.

A $37 tower and a $15,000 video game

If you’re poor, well… Fable also knows how to work for cheap. For less than $40 (two months of Claude Pro) it built a cute orange cylinder.

Another experiment simulated water-balloon physics for $91. It’s worth noting this isn’t a model intended for routine tasks. This is for serious work and people with deep pockets.

In its launch announcement, Anthropic said the new models generate output up to 30% faster than their predecessors. The company also says Fable helped solve two open theoretical-physics problems involving black holes and design three functioning electronic devices, claims that will need independent scrutiny.

Anthropic's internal FrontierCode 2.0 evaluation, which measures the percentage of proposed coding changes that would be accepted into real open-source projects, put Fable 5.2 at 49.1%, compared with 32.4% for Fable 5.1. That helps explain why users are pushing it beyond simple chat responses.

Fable and Mythos share the same underlying model, but Fable has stricter safeguards around dangerous biological and cybersecurity requests. Mythos is reserved for verified organizations working in those fields.

The standard API price is $8 per million input tokens and $40 per million output tokens, down from the previous generation's $10 and $50. Optional fast mode can generate output up to 2.5 times faster, but doubles the rates to $16 and $80.

For contrast, Kimi 3.1 Pro, a model considered by many as the best Chinese AI model costs $2 per million input tokens and $10 per million output tokens. The latest Deepseek model costs $0.6 and $1.98 outside of peak hours.

Per Anthropic’s standards, Fable’s price is still twice the per-token price of Claude Opus 5.5, which Anthropic recommends for everyday work. Its flagship is meant for problems the cheaper models struggle to finish, not for asking whether your email sounds too aggressive.

The cost debate has history. When Fable 5 was released, it burned through some subscribers' quotas in minutes. When Fable 5.1 arrived in September, Anthropic kept premium pricing while improving discounts for reused inputs.

Just last week, speculation swirled around a supposed Fable 5.5. The actual release is 5.2, with cheaper token rates but enough appetite to turn a hobby project into a serious expense.

For ordinary subscribers, Anthropic's launch offer gives Pro users and standard Team seats Fable access for one week, capped at half their weekly allowance, plus a reset. Max, Ultra and eligible premium seats get one to three resets depending on subscription history.

Pro users' promotional access ends November 16, after which Fable returns to paid credits on their plans. Resets for eligible Max and Ultra subscribers last until March 8, 2027. Berman's $14,710 game offers a fairly convincing reason to check the meter.

Anthropic, last we checked, doesn’t accept kidneys as a method of payment.