Canonical event

Claude Sonnet 4.5 is released

Anthropic releases Sonnet 4.5 alongside agent development and context-management tools.

Artifacts

Claude Sonnet 4.5 is released
documented_by · official_announcement

Signals

Anthropic releases Sonnet 4.5 alongside agent development and context-management tools. Long-horizon vendor demonstrations do not establish unattended success rates across real production tasks.
supported inference

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