24-Hour Pre-Deployment Alignment Review

Description

Institutional pause instituted for the first time in Anthropic's history before widespread internal use of an early Mythos Preview version. Explicit rationale in system card: 'to gain assurance against the model causing damage when interacting with internal infrastructure.' Establishes a new release gate above even internal deployment — review of whether a model is safe on Anthropic's own systems, not just customer ones.

Key claims

Relations

Sources

src-20260409-a5ff5a259c43