Anthropic stated that Claude Fable 5.2 and Claude Mythos 5.2 generate artificial intelligence outputs 30% faster than previous 5.1 generation models

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Anthropic made Claude Fable 5.2 available on paid Claude plans, Claude Code, the Claude Platform, Amazon Web Services, Google Cloud, and Microsoft Azure

Anthropic said Claude Fable 5.2 and Mythos 5.2 generate token outputs up to 30% faster than Fable 5.1 and Mythos 5.1, their predecessors

Claude Fable 5.2 and Claude Mythos 5.2 are built on the same underlying model, but Fable 5.2 includes classifiers that block high-risk cybersecurity and research biology tasks

Anthropic priced Claude Fable 5.2 and Claude Mythos 5.2 at $8 per million uncached input tokens and $40 per million output tokens, representing a 20% cost reduction over Fable 5.1 and Mythos 5.1, their predecessors

Anthropic said Claude Fable 5.2 scored 69.9% on FrontierSWE v2, outperforming GPT-6 Astra at 65.5% and Gemini 4 Carbon at 61.2%

Anthropic launched Claude Fable 5.2 and Claude Mythos 5.2 on November 9, 2026, targeting coding, reasoning, and AI agent tasks

Anthropic said Claude Fable 5.2 scored 51.4% at Max effort on Zapier's AutomationBench business automation test, behind Gemini 4 Carbon's score of 53.9%

Anthropic introduced an optional Fast mode for Fable 5.2 and Mythos 5.2 that increases token generation speed by up to 2.5 times at $16 input and $80 output per million tokens

Anthropic said during pre-release testing, 1,000 Fable 5.2 agents formalized the proof of Fermat's Last Theorem in Lean in 30 hours, compared to 26% completion in 18 hours by Opus 5.5

Anthropic said Claude Fable 5.2 scored 49.1% at Xhigh effort on the FrontierCode 2.0 agentic coding benchmark, leading GPT-6 Astra at 42.8% and Gemini 4 Carbon at 41.1%

Anthropic's Batch API pricing for Fable 5.2 and Mythos 5.2 halves input and output rates to $4 and $20 per million tokens, respectively

On November 9, 2026, Anthropic released Claude Mythos 5.2, an advanced artificial intelligence model restricted to vetted organizations through its Life Sciences and Cyber Verification Programs

On November 9, 2026, Anthropic released Claude Fable 5.2, its most advanced publicly available artificial intelligence model, targeting complex technical tasks in engineering, mathematics, and robotics

The release of Claude Fable 5.2 and Mythos 5.2 marks Anthropic's first frontier model launch since CEO Dario Amodei advocated slowing AI development in September 2026

Anthropic priced Claude Fable 5.2 and Mythos 5.2 at $8 per million input tokens and $40 per million output tokens, representing a 20% cost reduction from generation 5.1

On an 803-prompt evaluation set created by Nous Research, Arete-27B reduced the proportion of responses containing Chinese state propaganda from 22 percent to 0.9 percent

In the freedom of expression evaluation category, Arete-27B reduced the propaganda response rate from 60 percent to 1 percent while raising the factual accuracy score from 0.89 to 2.44

Arete-27B raised the factual accuracy score on the Nous Research benchmark to 2.98 out of 5, compared to 2.32 out of 5 for base Qwen3.8-27B

Nous Research evaluated Arete-27B using xAI's Grok 4.7 as a judge model to grade 803 prompts across seven value categories against facts from cited sources

On the 803-prompt Propaganda_Eval benchmark, answers scoring zero on factual accuracy dropped from 359 for Qwen3.8-27B to 216 for Arete-27B