What changed
AWS has announced the availability of Claude Fable 5.2 and Claude Mythos 5.2 on Amazon Bedrock and the Claude Platform. Fable 5.2 is described as Anthropic’s most capable generally available model for technical work, particularly in coding and the sciences. Mythos 5.2 is available through Anthropic’s verification programs for advanced work in cybersecurity and life sciences.
What this means in practice
Fable 5.2 is intended for complex tasks such as agentic coding across large codebases, long-running agents for multi-day work, scientific research, financial analysis, and design for 3D, hardware, and motion. It can verify its own output, run unattended for extended periods, and optimize as it goes. Mythos 5.2 is available for cybersecurity and life sciences through verification programs, with specific use cases including security engineering, red teaming, penetration testing, and biomolecular design.
Limitations and availability
Claude Fable 5.2 and Mythos 5.2 are available on Amazon Bedrock through US Geo CRIS and Global CRIS inference profiles. They are also available on the Claude Platform on AWS in all regions where the service is offered. For authorized work in cybersecurity and life sciences, access to Mythos 5.2 requires participation in Anthropic’s verification programs. Data retention and enterprise safeguards are in place, with Fable 5.2 designated as a Covered Model requiring up to 30 days of data retention and human safety review. Customers can use Fable 5.2 with zero data retention until Enterprise Frontier Safeguards (EFS) is available, at least through June 30, 2027.
To get started with Fable 5.2 on Amazon Bedrock, users can open the Amazon Bedrock console, select the Test or Playground option, and choose Fable 5.2 as the model.
Programmatically, the model can be called using the Anthropic Messages API through the AWS SDK or the AWS CLI. Developers can also use the claude-api skill in Claude Code to migrate existing codebases to Fable 5.2, which helps update model references, adjust settings, and clean up outdated parameters.
