Claude Fable 5 Internal Chain-of-Thought Leaks, Looks Like Alien Language

mark_k · x · 2026-07-03

A Reddit user prompted Claude Fable 5 to leak its implicit internal chain-of-thought (CoT) reasoning process. They found it vastly different from the polished outputs users typically see, resembling an almost "alien language" mixed with logical symbols, far removed from standard natural language. It is speculated that this highly compressed format is used for token efficiency, while internal reasoning chains have remained a closely guarded secret among AI labs.

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