Fable 5.2 reaches Bedrock while Mythos 5.2 stays gated

AWS said on November 9, 2026 that Claude Fable 5.2 is now available on AWS. The What's New post calls it Anthropic's most capable generally available model for technical work and says it is open to all customers. A machine-learning blog post announces both Claude Fable 5.2 and Claude Mythos 5.2 on Amazon Bedrock and Claude Platform on AWS. Mythos 5.2 is the same underlying model, with its full cyber and bio capabilities retained, and AWS says it is available only through Anthropic's verification programs.

Anthropic recommends Fable 5.2 for software engineering, scientific research, and finance. The blog says Mythos 5.2 covers two high-risk domains, available only through those programs: security engineering, red teaming, and penetration testing, and life-sciences research, especially biomolecular design and research synthesis.

Where you can call them

Customers reach Fable 5.2 on Amazon Bedrock or Claude Platform on AWS. On Bedrock, both models are offered through US Geo CRIS and Global CRIS inference profiles. The blog points to Bedrock documentation for the full list of supported Regions. Claude Platform on AWS offers both models in every Region where that service is offered, with Mythos 5.2 still limited to Anthropic's verification programs. The playground steps—Test, Playground, then Fable 5.2—and the sample ID global.anthropic.claude-fable-5-2 on bedrock-runtime are for Fable 5.2 only.

If Fable declines

A declined cyber security query can be retried on Opus 4.8, and a declined biology query on Opus 5. On Bedrock the retry is your code's job, not an automatic switch. If the declined request hit the prompt cache, the refusal includes a fallback credit token. Send that token with the retry and it is billed as cache reads, so you do not pay to write the same cache twice.

Retention before the first call

Anthropic has designated both Fable 5.2 and Mythos 5.2 as covered models, which require data retention for safety monitoring. For Fable 5.2, default use requires retention for up to 30 days and human safety review. On Bedrock, Amazon personnel perform that review within the AWS boundary. Set the aws_review data retention mode on the account or project before you invoke the model.

Enterprise Frontier Safeguards, built in collaboration with AWS, combines zero data retention with safeguards for detecting misuse, storing data in cloud infrastructure the customer controls. Until it is available, eligible customers can use Fable 5.2 with zero data retention for internal use through at least June 30, 2027. The posts do not say that window applies to Mythos 5.2.

Try Fable 5.2 in the Bedrock playground or on Claude Platform on AWS, and read the November 9 What's New note with the machine-learning blog before you pin a model ID. If you need the retained cyber or bio capabilities, confirm Anthropic's verification programs before you plan on Mythos 5.2.

Sources

• Introducing Claude Fable 5.2 on AWS aws.amazon.com
• Claude Fable 5.2 is now available on AWS aws.amazon.com