US-based AI company Anthropic has opened its most powerful model, Mythus, which had been kept in a test environment for months, to general use. This move came after a long-delayed launch due to security concerns.
Anthropic stated that the model was previously available only to selected companies and security or financial institutions with limited access. Now, different access levels are being defined for both corporate users and paid individual subscribers.
Access Through Two Separate Versions
The new package includes Mythus 5 for corporate use and a lighter version called Fable 5 for general users. The company announced that Fable 5 is available to all paid Claude subscribers with varying usage limits.
Anthropic explained that it deliberately limits the model's capacity in certain sensitive areas for security reasons. This includes commands related to chemical engineering, cybersecurity, biosecurity, and distillation methods.
In such cases, the system automatically redirects users to the previously introduced Opus 4.8 model. This approach allows the company to expand the powerful model's availability while keeping risky use cases on a separate layer.
Performance and Criticism
Anthropic claims that Fable 5 outperforms all its previous models and excels in complex tasks. The company also noted that the model delivers strong results in operations that maintain broad context and in multi-step tasks.
However, the model's introduction sparked debate in some circles in recent months. In technical reviews, some experts argued that Anthropic exaggerated the model's capabilities, while some companies testing the model supported the company's claims.
Technology assessments reported that Fable 5 stood out particularly in coding and information-intensive tasks, performing well in single-command application generation tests. Another review highlighted the model's more pronounced advantage in tasks requiring long context.
Evaluations from AI tool platforms like GenSpark also emphasized the model's strength in coding. In coding tests such as Base 44, the model's rapid production capability was notable.
Anthropic has currently made the new model available for free trial but announced that this offer will end at the end of June. Afterwards, usage will switch to consumption-based billing, with the possibility of changes to the payment system as infrastructure is strengthened.
The model's announcement coincides with a period when the company is preparing to go public. During the same period, companies like OpenAI and SpaceX are also known to be taking steps that increase investor interest.
