Anthropic has unveiled Claude Fable 5, marking the first time its Mythos-class model is accessible to the public. This new AI model is designed with strict safety protocols to mitigate risks associated with sensitive areas such as cybersecurity and biology.
Fable 5 is touted for its capabilities in software engineering, knowledge work, and visual tasks. However, in high-risk domains, it defaults to the previous version, Claude Opus 4.8, to ensure safety.
Expanded Access
Initially launched in April as a preview, the Mythos model was limited to select partners due to security concerns. Recently, Anthropic broadened access to hundreds of organizations across 15 countries, particularly those managing critical infrastructure.
Fable 5 is now available through Anthropic’s Claude API and various subscription plans. From June 22, it will be included in Pro, Max, Team, and seat-based Enterprise plans at no additional cost, after which it will require usage credits.
New Developments
Alongside Fable 5, Anthropic is rolling out Mythos 5 to approved organizations, enhancing the capabilities of its advanced models.
Safety Measures
In preparation for the public launch, Anthropic conducted extensive testing to identify and mitigate potential vulnerabilities. The company engaged in over 1,000 hours of internal testing and collaborated with external teams, successfully preventing universal jailbreaks.
Despite these precautions, Anthropic acknowledges the possibility of new attack vectors. Therefore, all traffic will be retained for 30 days to help defend against complex threats, although the data will not be used for training purposes.
Performance Insights
Early data indicates that Fable 5 operates independently in 95% of sessions. Third-party evaluations highlight its strong performance in complex analytical tasks, with analytics firm Hex reporting a 90% score on their benchmark.
Other organizations, such as Base44 and Genspark, noted Fable's superior ability to create full applications and excel in UI design and game coding.
Pricing Structure
The pricing for Fable 5 and Mythos 5 is set at $10 per million input tokens and $50 per million output tokens, which is double the rate of Opus 4.8. This pricing may deter some enterprises, especially those already facing high AI costs.
Future Outlook
Anthropic anticipates high demand for Fable 5, with organizations like Rakuten expressing optimism about its potential to enhance operational efficiency.
