Anthropic’s Fable is the most locked-down public model we’ve ever seen

How Anthropic decides which questions are too dangerous for Claude to answer.

This post originally appeared in Understanding AI.

“Anthropic said the degraded quality of responses ‘will not be visible to the user.’”

When Anthropic announced its latest model, Claude Fable 5, on Tuesday, a statement tucked away on page 13 of the system card attracted an immediate outcry. AI researcher Nathan Lambert called it “appalling.” Dean Ball, who worked on AI policy in the Trump White House, wrote that it was “shockingly hostile.” Many others joined in the pile-on.

The announcement that got everyone so mad? Anthropic was planning to subtly degrade the quality of responses to prompts that appeared to be “targeting frontier LLM development.” Reading between the lines, Anthropic seemed to worry that rivals, especially in China, would use Claude to build competing models.