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Claude Sonnet 4.5

Anthropic releases Claude Sonnet 4.5, emphasizing agent building, coding strength, and computer-use capabilities.

Model Release

What Happened

Anthropic released Claude Sonnet 4.5 and paired the model launch with product and platform upgrades (including improvements related to Claude Code and developer tooling).

Why It Matters

Sonnet 4.5 is a representative “frontier coding model” release: the announcement tightly couples model capability claims with the surrounding infrastructure needed for real agent workflows (IDE integrations, checkpoints, longer-running tasks).

Technical Details