One Shared Claude Model, Two Distinct Safeguard Sets: Fable 5.2 and Mythos 5.2 Are Officially Released
Anthropic has split the exact same base model into two variants with distinct safety tiers, named Fable 5.2 and Mythos 5.2. Fable 5.2 scores 49.1% on FrontierCode 2.0, is priced at $8 per million input tokens and $40 per million output tokens, and supports a 1M-token context window.
Anthropic has officially released Claude Fable 5.2 and Claude Mythos 5.2. As covered by MarkTechPost author Asif Razzaq, the two names point to the exact same underlying model, with the only difference being their safeguard level, that is, the tier of built-in safety guardrails.
The public parameters for Fable 5.2 are very specific: it earns a 49.1% score on the FrontierCode 2.0 benchmark, its API is priced at $8 per million input tokens and $40 per million output tokens, and it comes with a 1M-token context window. There are no separate benchmark results, pricing or context window specifications noted for Mythos 5.2 in published materials. The only confirmed detail is that it shares the exact same base model with Fable 5.2, and differs only in safety configuration.
The noteworthy part of this launch is not the new naming labels. Model releases are increasingly evolving toward product tiering: the core capability base remains identical, while separate safety rules are split into different SKUs. For enterprise procurement teams, compliance requirements can now map directly to a dedicated model name. For developers, you have to clarify which name corresponds to which guardrail tier, what use cases it allows, and what requests it will reject before making any calls. The published materials do not expand on the specific restrictions of Mythos 5.2, so do not rely on guesswork.
Fable 5.2's 1M context window and 49.1% FrontierCode 2.0 score clearly target use cases including large long-form codebases, lengthy documents, and multi-turn agent tasks. The $40 per million output token price is not low, so teams with high-frequency usage need to calculate costs in advance. With safety level becoming an independent selling point, choosing a model no longer only depends on benchmark scores and pricing — you also need to confirm whether it is willing to support your specific use case.
Original source: MarkTechPost, By Asif Razzaq, Anthropic Launches Claude Fable 5.2 and Mythos 5.2: Same Model, Different Safeguards.
发布时间: 2026-11-10 22:59