Claude Fable 5.2 is Anthropic’s newest public frontier model. It launched on 9 November 2026 at $8 per million input tokens and $40 per million output tokens, which is 20% below the Fable 5.1 price. Its sibling, Claude Mythos 5.2, is the same underlying model with fewer safeguards, open only to vetted cybersecurity and life-sciences organisations. Anthropic says both are faster, cheaper and stronger than the 5.1 versions, yet Fable 5.2 still costs twice as much per token as Opus 5.5. This guide separates verified facts from claims, shows the cost in rupees and tells you which model to pick.
Key takeaways
- What: Claude Fable 5.2 and Claude Mythos 5.2 are one model sold two ways. Fable is for everyone; Mythos is application-only.
- When: released on 9 November 2026. Fable runs in the Claude apps, Claude Code, the API, AWS, Google Cloud and Microsoft Azure.
- Price: $8 input and $40 output per million tokens, about ₹751 and ₹3,757 at ₹93.93 per dollar. Opus 5.5 costs $4 and $20.
- Performance: Anthropic reports 49.1% on FrontierCode 2.0 against 45.5% for Opus 5.5. Artificial Analysis puts it first with 65 points.
- Catch: Anthropic itself recommends Opus 5.5 for most daily work, and early Reddit users say it drains plan limits fast.
Published: 10 November 2026. Last updated: 10 November 2026, morning IST. Status: released on 9 November (US time); independent testing is still early.
Table of Contents
Table of Contents
What are Claude Fable 5.2 and Claude Mythos 5.2?
Claude Fable 5.2 and Mythos 5.2 are Anthropic’s two newest frontier models, built for hard, open-ended technical work such as large software projects, mathematics, science and robotics. Anthropic says they are “the same underlying model.” The difference is access: Fable carries strong cybersecurity and biology safeguards so it can go to all users, while Mythos has those restrictions relaxed for vetted organisations.
Think of one engine fitted into two cars. Fable is the road-legal version with a speed limiter. Mythos is the track version, handed only to licensed drivers. Both come from Anthropic, which is now preparing one of the largest stock-market listings in tech. Our Anthropic IPO explainer covers that side of the story.
When was Fable released and who can use it?
Anthropic released Fable 5.2 on 9 November 2026, and the model ID is claude-fable-5-2. According to Anthropic’s announcement, it is available on all major platforms, including Amazon Web Services, Google Cloud and Microsoft Azure. Anthropic’s model documentation lists it as the latest model, with retirement not sooner than 9 November 2027. It offers a 1 million token context window and a June 2026 knowledge cutoff.
Mythos 5.2 is different. Cybersecurity professionals apply through the Cyber Verification Program, and life-sciences researchers apply through the Life Sciences Verification Program. Claude Enterprise customers can also use Claude Security, which now runs on Mythos 5.2 to scan code for vulnerabilities. For subscribers, Anthropic is giving extra Fable usage this week, and Fable counts for up to 50% of weekly limits on Pro plans and standard Team seats.
| Date | What happened | Source |
|---|---|---|
| April 2026 | Anthropic introduces Mythos to a select group of organisations because of its cybersecurity strength | CNBC |
| June 2026 | Fable arrives as a public version of Mythos with extra safeguards | CNBC |
| September 2026 | Fable 5.1, Mythos 5.1 and Opus 5.5 launch; CEO Dario Amodei calls for slowing AI development | Decoder, CNBC |
| 9 November 2026 | Fable 5.2 and Mythos 5.2 launch | Anthropic |
How much does the Fable 5.2 price come to in India?
The Fable 5.2 price is $8 per million input tokens and $40 per million output tokens, which is ₹751 and ₹3,757 at ₹93.93 per US dollar, the rate at which the rupee closed on 9 November according to Reuters. That is 20% lower than Fable 5.1’s $10 and $50, and 20% lower than OpenAI’s GPT-6 Astra, as Fortune reports.
| Model | Input per 1M tokens | Output per 1M tokens | In rupees (input / output) |
|---|---|---|---|
| Claude Fable 5.2 | $8 | $40 | ₹751 / ₹3,757 |
| Same model, fast mode | $16 | $80 | ₹1,503 / ₹7,514 |
| Claude Fable 5.1 (previous) | $10 | $50 | ₹939 / ₹4,696 |
| GPT-6 Astra (OpenAI) | $10 | $50 | ₹939 / ₹4,696 |
| Claude Opus 5.5 | $4 | $20 | ₹376 / ₹1,879 |
| Claude Sonnet 5.5 | $2 | $10 | ₹188 / ₹939 |
The cached-input price is a bigger gap. Fortune reports Fable cached tokens at 20 cents per million, against $1 for Astra. Batch jobs get a 50% discount on input and output, according to Anthropic’s docs. Fast mode, which speeds up output by up to 2.5 times, doubles the price.
Here is my own worked example. A job that reads 1 million tokens and writes 200,000 tokens costs $16 (₹1,503) on Fable, $8 (₹751) on Opus 5.5, $20 (₹1,879) on Astra and $32 (₹3,006) on Fable fast mode. This is my calculation from list prices; real bills depend on how many tokens each model uses to finish a task.
How good are the Fable 5.2 benchmarks?
On Anthropic’s own table, the new model leads most tests but not all. It beats Opus 5.5, GPT-6 Astra and Gemini 4 Carbon on coding, computer use, robotics and expert reasoning, and it trails Carbon on one business-workflow test. These Fable 5.2 benchmarks are run by the vendor, so treat them as claims until outside testers repeat them.
| Test (higher is better) | Fable 5.2 | Fable 5.1 | Opus 5.5 | GPT-6 Astra | Gemini 4 Carbon |
|---|---|---|---|---|---|
| FrontierCode 2.0 (agentic coding) | 49.1% | 32.4% | 45.5% | 42.8% | 41.1% |
| AutomationBench (business workflows) | 51.4% | 31.4% | 42.5% | 41.4% | 53.9% |
| Terminal-Bench-Science 0.1 | 74.6% | 52.6% | 58.7% | 68.1% | 64.8% |
| OSWorld 2.1 (computer use) | 89.3% | 83.5% | 87.2% | 79.5% | 81.5% |
| RoboDojo Sim (robotics) | 64.9% | 27.6% | 39.4% | 29.8% | n/a |
| Remote Labor Index (knowledge work) | 41.3% | 17.9% | 21.3% | 20.8% | n/a |
| Humanity’s Last Exam (with tools) | 74.2% | 65.6% | 67.7% | 57.2% | n/a |
The independent view is more measured but still positive. The Decoder reports that on the Artificial Analysis Intelligence Index v5, Fable scores 65 points, five ahead of Gemini 4 Carbon (60), six ahead of Opus 5.5 (59) and fifteen ahead of Fable 5.1. It places first in five of nine individual tests there. It falls behind on agentic knowledge work and on Terminal-Bench 4.0, where it scores 60% and ties Opus 5.5.
My own arithmetic on Anthropic’s table: Fable is 3.6 points (about 8%) ahead of Opus 5.5 on FrontierCode 2.0, but 25.5 points ahead on RoboDojo and nearly double on the Remote Labor Index. The biggest gains are in robotics and long, multi-step work, not in everyday coding.
Cost matters here. Anthropic says Fable at High effort scores 45.3%, about level with Opus 5.5’s best 45.5%, for roughly half the cost per task. Yet The Decoder says Artificial Analysis found peak-quality tasks cost an average $26.50 for Fable, about 2.6 times the $10 for Opus 5.5. Both can be true: the cost depends on the effort setting you choose.
What can Fable actually do?
It is best at long, ambiguous projects that need planning, checking and many steps. Anthropic’s examples below come from its own pre-release tests.
Can Fable write software on its own?
Anthropic says over 90% of the changes merged into its core codebase are now written by Claude, with human guidance. In one experiment, one engineer asked Fable to design a prototype operating system from an empty folder. The model coordinated over 1,000 subagents for eight days and produced a system that boots on a laptop.
Can it do real science and maths?
Anthropic says Fable solved two open problems in theoretical physics about black holes. It also reports that about 1,000 Fable agents formalised the proof of Fermat’s Last Theorem in the Lean language in 30 hours. An earlier unreleased research version of Claude needed 11 days. In the same setup, Opus 5.5 finished only 26% in 18 hours.
Can it design hardware and control robots?
With circuit-board maker Diode, Anthropic asked Fable to design a voice-assistant hub, a USB speakerphone and a handheld virtual pet from a one-paragraph prompt. All three worked without electrical changes, and each board was ready for manufacture in under a day. On the RoboDojo simulator, Fable scores 64.9% against 29.8% for GPT-6 Astra. See our report on the Meta humanoid robot for why labs chase robotics.
What is Claude Mythos 5.2 and who can get it?
Claude Mythos 5.2 is the cybersecurity and biology-capable version of the same model, available only to vetted organisations. Anthropic calls it its most capable model for cybersecurity engineering. On its internal CVE Rediscovery test of 1,829 known vulnerabilities, Mythos 5.2 scores 89.6%, against 81.3% for Opus 5.5 without safeguards and 78.3% for Mythos 5.1.
A security company told Anthropic that one in six confirmed bugs Mythos 5.2 found were missed by every other frontier model it tested. Anthropic adds a caution: on its own evaluations, raw vulnerability identification is roughly on par with Opus 5.5, so tester anecdotes should not be over-read. In biology, Mythos 5.2 modelled 28 of 34 virus capsids accurately in a gene-therapy task.
Fable blocks high-risk cyber work such as penetration testing and exploit generation, plus most research biology. A blocked cyber request falls back to Opus 4.8, and a blocked biology request falls back to Opus 5. Anthropic says early testing showed about 55% fewer unnecessary blocks than Fable 5.1.
Fable 5.2 vs Opus 5.5: which model should you use?
For most daily work, use Opus 5.5. Anthropic’s own advice is to start there and move up to Fable or Mythos only for the hardest tasks, or down to Sonnet 5.5 and Haiku 5.5 for speed and cost. The Fable 5.2 vs Opus 5.5 choice comes down to the size of the problem and the size of your budget.
| Your situation | Best starting model | Why |
|---|---|---|
| Everyday coding, writing, analysis | Opus 5.5 | Half the token price; Anthropic’s recommended daily driver |
| Large multi-repository refactors, long agent runs | Fable | Strongest on long, multi-step engineering work in Anthropic’s tests |
| Maths, science, robotics research | Fable | Biggest benchmark gaps over Opus 5.5 are here |
| High-volume, simple tasks | Sonnet 5.5 or Haiku 5.5 | Lower cost and faster replies |
| Authorised security or biology research | Mythos 5.2 (apply) | Fewer safeguards, vetted access only |
| Planning and delegating to cheaper models | Fable as orchestrator | Anthropic suggests it can advise or orchestrate smaller models |
What are people saying about Fable?
Reaction to Fable 5.2 is mixed: impressed by the capability, wary of the cost and the usage limits. In a r/Anthropic thread, one commenter noted that a 1,000-agent, eight-day run would cost several million dollars in API tokens, and another said their session usage disappeared within minutes after asking Fable to spawn a few agents. Another user testing 15 models on their own questions found Fable scored highest at 74% but was among the least cost-efficient. These are individual reports, not measurements.
Fortune frames the launch as a price move. It says the models are Anthropic’s answer to GPT-6 Astra and could help Claude Code win back developers who moved to cheaper tools. Our GPT-6 explainer covers the OpenAI side of that race.
What are the risks and open concerns with Fable 5.2?
The main concerns about Fable 5.2 are about testing, speed of AI progress and data handling. Anthropic’s own announcement admits that both models say they suspect they are being evaluated more often than any recent Claude model, which makes it harder to predict real-world behaviour. TechCrunch adds that the system card describes stronger covert capabilities on several evaluations, although Anthropic argues low absolute scores support its safety claims.
TechCrunch also reports that a METR assessment suggested Anthropic’s internal models were speeding up its AI progress by about 2x. Anthropic says it deliberately limited training gains in AI-research skills: on kernel optimisation and language-model architecture, Fable performs about level with Opus 5.5.
Source conflict on data retention: TechCrunch says Fable works with zero data retention through Enterprise Frontier Safeguards. Anthropic’s documentation says the model requires 30-day retention and is not available under zero data retention unless expressly authorised, and the AWS announcement says eligible customers can use zero data retention until the safeguards system arrives. Enterprise Frontier Safeguards is in private beta, so check your contract before sending sensitive data.
Fable 5.2 in India: cost, access and what to watch
Indian developers, students and startups can use Fable 5.2 through the Claude apps on eligible paid plans, the Claude API, or the cloud platforms Anthropic lists. I found no Indian-language benchmark in the launch post, and no India-specific pricing, so the rupee numbers above are simple dollar conversions. Taxes such as GST and card or foreign-exchange charges will add to your bill.
The rupee matters: at ₹93.93 per dollar, a heavy agent run that burns $100 of tokens costs about ₹9,393. Because cost per task rises with the effort level you choose, test with a small budget first and set spending alerts. Students and hobbyists should start on Opus 5.5 or Sonnet 5.5 and move up only when a task fails.
How to try Fable step by step
- Update the Claude app or Claude Code to the latest version and choose Fable from the model picker (Anthropic’s launch promotion covers eligible paid plans).
- Start at Medium effort. Anthropic says Medium is the default in Claude apps and Claude Code, while the API default is High.
- Give it a hard, well-defined task, such as a multi-file refactor, rather than a quick question. Opus 5.5 handles quick questions for half the price.
- For API use, call
claude-fable-5-2and leave out temperature, top_p and top_k; the docs say these return an error. Adaptive thinking is always on. - Watch your usage meter during the first runs and avoid spawning many subagents until you know how fast limits drain.
- Never paste confidential data until you have checked the retention rules above.
Common mistakes and myths about Fable and Mythos
- Myth: Mythos is a different, smarter model. Anthropic says Fable and Mythos are the same underlying model with different safeguards.
- Myth: 20% cheaper means cheap. It is cheaper than Fable 5.1 and Astra but still twice the per-token price of Opus 5.5.
- Mistake: using Fable for everything. Anthropic recommends Opus 5.5 for most daily work.
- Myth: Fable is just Opus 5.5 renamed. A Reddit commenter guessed this, but it is unverified, and Anthropic lists Opus 5.5 as a separate model.
- Mistake: trusting vendor benchmarks alone. Wait for independent tests on your own tasks.
- Myth: anyone can use Mythos 5.2. Access is by application through the verification programs.
What happens next with Fable and Mythos?
- Anthropic IPO: CNBC says the listing could come as soon as next week, with a target valuation of $1 trillion to $1.5 trillion.
- Independent tests: more results from Artificial Analysis, METR and community evaluators should arrive in the coming days.
- Rival launches: Google has not released Gemini 4 Carbon, and OpenAI recently debuted GPT-6 Cyber.
- Mythos access: Anthropic says it is expanding the verification programs.
- This page: Askhari will update this same URL with dated notes as facts change.
Related reading on Askhari
- Anthropic IPO explained: what the S-1 says
- Claude Mythos 5.5 rumours: what was claimed before this launch
- Gemini 4 Xenon leak versus Claude Fable 5.5
- Gemini 4 Carbon: Google’s rival model
- Gemini 4 Argon price guide
- GPT-6 explained
What we don’t know yet
- How Fable performs on independent tests beyond Artificial Analysis.
- Real-world cost per task for developers, since token use varies.
- When Mythos 5.2 access will widen beyond the verification programs.
- Whether the unnamed model behind a new quantum-computing proof announced on 9 November was Fable 5.2; Anthropic has not confirmed it.
Watch: Fable cost compared with Opus 5.5
Frequently asked questions about Fable 5.2
What is Claude Fable 5.2?
Claude Fable 5.2 is Anthropic’s most capable generally available model, released on 9 November 2026 for hard coding, science and long-running agent work. It costs $8 per million input tokens and $40 per million output tokens.
What is the difference between Fable 5.2 and Mythos 5.2?
They are the same underlying model. Fable has strong cybersecurity and biology safeguards and is open to all users, while Mythos 5.2 relaxes them for vetted organisations.
Is Fable 5.2 better than Opus 5.5?
On Anthropic’s tests, yes, by a few points on coding and by a wide margin on robotics and long tasks. But it costs twice as much per token, and Anthropic recommends Opus 5.5 for most daily work.
Is Fable 5.2 available in India?
Yes, through the Claude apps, API and the listed cloud platforms, priced in dollars. At ₹93.93 per dollar, the input price is about ₹751 per million tokens. Mythos 5.2 needs an approved application.
Is Fable 5.2 safe?
Anthropic rates the risk of unsafe behaviour in high-stakes situations as low, with testing by outside groups. It also admits that the models often suspect they are being tested, so safety claims remain partly unproven.
Hari’s take
Fable 5.2 is a real step up from 5.1, and the price cut is welcome, but the headline is not “cheaper.” It is “still twice Opus.” For most readers the smart move is boring: stay on Opus 5.5, and call Fable only when a task has failed twice.
What worries me more than the price is how much of this evidence comes from Anthropic itself, days before its listing. Bookmark this page. I will update the same URL as independent tests and usage-limit reports arrive, so you always have one place to check before you spend.
Sources: Anthropic, 9 Nov 2026 · Claude Platform docs · Fortune, 9 Nov 2026 · TechCrunch, 9 Nov 2026 · The Decoder, 9 Nov 2026 · CNBC, 9 Nov 2026 · AWS · The Verge, 9 Nov 2026 · Reuters, 9 Nov 2026 · Reddit r/Anthropic. Last updated 10 November 2026.
