Claude Fable 5.2 lands on Amazon Bedrock with new data-retention rules and a migration skill

AWS ML Blog · rss · 2026-11-10

AWS ML Blog announces that Anthropic's Claude Fable 5.2 and Claude Mythos 5.2 are now available on Amazon Bedrock and Claude Platform on AWS.

What the models do

Fable 5.2 is positioned as the most capable general model for technical work: coding, math, and science. It handles ambiguous multi-step tasks, verifies its own output, and can run unattended for hours to days. Target use cases include agentic coding across large multi-repo codebases, multi-day agent orchestration, research and formal proofs, quant finance, and 3D/hardware/motion design.
Mythos 5.2 is restricted to Anthropic's verification programs for two high-risk domains: cybersecurity (red teaming, pentesting) and life sciences (biomolecular design). Anthropic reports fewer hallucinations and more honest self-reporting than Opus 5.5, Sonnet 5.5, and Mythos 5.1.

Data retention and safeguards

Fable 5.2 is designated a Covered Model: by default, usage requires up to 30 days of data retention with human safety review, performed by Amazon personnel within the AWS boundary via the awsreview retention mode.
Enterprise Frontier Safeguards (EFS), built with AWS, combines zero data retention with misuse detection; a customer-managed-key version isn't live yet, and eligible customers can use ZDR through June 30, 2027.
Declined cybersecurity/biology queries can be retried on Opus 4.8/Opus 5; a cache-hit refusal includes a fallback credit token so retries bill as cache reads.

Getting started and migration

The post includes a Boto3 example, noting Fable 5.2 is a reasoning model, so you must select the text block rather than a fixed index.
Claude Code's open-source claude-api skill handles migrations (/claude-api migrate): updating model IDs, moving to adaptive thinking, cleaning deprecated parameters, recommending outputconfig.effort, plus cache hit-rate optimization and context compaction. It's also bundled into CodeRabbit, JetBrains IDEs, Resolve AI, and Warp.

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