Claude Fable 5: The first Mythos model is powerful, expensive, and heavily filtered
Quick Answer
Anthropic's Claude Fable 5, the inaugural model in the Mythos class, excels in benchmarks with a 95% SWE-bench Verified score but comes at a steep cost of $10 to $50 per million tokens.
Quick Take
The model employs strict safety filters that block 9% of requests, alongside a new 30-day data retention policy affecting all contracts.
Key Points
- Claude Fable 5 leads benchmarks with a 95% Verified score.
- The model's cost is significantly higher, ranging from $10 to $50 per million tokens.
- Strict safety filters block approximately 9% of user requests.
- A new 30-day data retention policy applies to all contracts, including zero-data-retention ones.
Source Excerpt
Anthropic has released Claude Fable 5, the first model in its new Mythos class. It leads nearly every benchmark, including Verified at 95 percent, but costs twice as much as Opus 4. 8 at 10 or 50 dollars per million tokens. Strict safety filters block about nine percent of requests, and a new 30-day data retention policy applies even to zero-data-retention contracts.
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