Anthropic launches Claude Fable 5.1 and Mythos 5.1, claiming up to 45% cost reduction for agentic tasks and improved performance, along with new data privacy options.
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<p class="wp-block-paragraph">Anthropic says its newest AI models, <a href="https://www.anthropic.com/claude-fable-and-mythos-5-1">Fable 5.1 and Mythos 5.1</a>, address criticisms from customers about price, data retention, and overzealous safeguards. The company claims <a href="https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1">Claude Fable 5.1</a> offers stronger performance than Fable 5, but costs around 25 percent less typically and up to 45 percent less for complex agentic tasks, thanks to reduced pricing on cached data that was already processed and stored.</p>
<p class="wp-block-paragraph">Along with the announcement, a slew of early impressions popped up, including from Every CEO Dan Shipper, <a href="https://x.com/danshipper/status/2094848951568474186">who claims</a>, "It's the strongest coding model we've used, but now it's fast, token-efficient, and crucially actually speaks like a norm …</p>
<p><a href="https://www.theverge.com/ai-artificial-intelligence/987830/anthropic-claude-fable-mythos-5-1">Read the full story at The Verge.</a></p>
# Anthropic launches Claude Fable 5.1 and says it’s up to 45 percent cheaper for agentic work
Source: [https://www.theverge.com/ai-artificial-intelligence/987830/anthropic-claude-fable-mythos-5-1](https://www.theverge.com/ai-artificial-intelligence/987830/anthropic-claude-fable-mythos-5-1)
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Stevie Bonifield
is a news writer covering all things consumer tech\. Stevie started out at Laptop Mag writing news and reviews on hardware, gaming, and AI\.
Anthropic says its newest AI models,[Fable 5\.1 and Mythos 5\.1](https://www.anthropic.com/claude-fable-and-mythos-5-1), address criticisms from customers about price, data retention, and overzealous safeguards\. The company claims[Claude Fable 5\.1](https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1)offers stronger performance than Fable 5, but costs around 25 percent less typically and up to 45 percent less for complex agentic tasks, thanks to reduced pricing on cached data that was already processed and stored\.
Along with the announcement, a slew of early impressions popped up, including from Every CEO Dan Shipper,[who claims](https://x.com/danshipper/status/2094848951568474186), “It’s the strongest coding model we’ve used, but now it’s fast, token\-efficient, and crucially actually speaks like a normal person\.”
Box CEO Aaron Levie[is another early access believer](https://x.com/levie/status/2094851976769257770), saying that his company’s agent with Fable 5\.1 picked up on subtleties and ambiguities in data that Fable 5 missed in the same test\. Meanwhile, Lisan al Gaib[points out](https://x.com/scaling01/status/2094850290855936277)that on benchmarks, Mythos 5\.1 with low reasoning scores the same as its predecessor set to Max reasoning\.
Fable 5\.1 also has “more precise safeguards” that Anthropic says are less likely to[block basic biology questions](https://www.theverge.com/ai-artificial-intelligence/947973/fable-wont-answer-basic-biology-questions)than Fable 5, but Mythos 5\.1 has the same biology restrictions as the previous model\. Anthropic also explained its progress on data retention, saying that[Enterprise Frontier Safeguards](https://www.anthropic.com/news/enterprise-frontier-safeguards)offer “complete privacy” by storing data on the customer’s cloud servers instead of its own, and will start rolling out later this fall\.
Anthropic says it’s “now allowing Fable 5\.1 to be used for identifying software vulnerabilities,” but it will still redirect some cybersecurity tasks to Opus models, like “penetration testing, exploit generation, and binary\-based vulnerability scanning\.” Claude Fable 5\.1 is now available on all platforms, while Mythos 5\.1 is available to Project Glasswing participants only\.
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- Stevie Bonifield
Anthropic has released Fable 5.1 and Mythos 5.1, cheaper and less restrictive AI models that achieve top benchmark scores and introduce enhanced privacy features for enterprise users.
Anthropic launched Claude Sonnet 5, a more powerful and cost-effective agentic model that competes with OpenAI's GPT-5.6 Sol and Google's Gemini 3.5 Flash, offering enhanced autonomy and lower prices.
Anthropic released Claude Opus 5, which it says approaches the capabilities of its more powerful Fable 5 model while offering stronger cybersecurity safeguards and lower pricing.
Anthropic has released Claude Fable 5.1, an upgraded AI model designed to excel at complex, multi-step tasks like financial modeling and code optimization, with improved stability and accuracy throughout lengthy processes.
Anthropic announced Claude Fable 5, its most powerful widely available AI model, part of the Mythos class previously considered too dangerous for public release. The model features new safeguards that fall back to Opus 4.8 in high-risk areas.