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model

Claude Opus 4.5

Claude Opus 4.5 is Anthropic's flagship large language model, used for coding, reasoning, and agentic tasks and benchmarked against other frontier AI systems.

Known aliases

  • Opus 4.5

Relationships

No evidence-backed relationships are recorded.

Current stories

build1 publisher

Simon Willison credits two November model releases with making coding agents reliable for daily use

Simon Willison says Claude Opus 4.5 and GPT-5.1, released last November, took coding agents from often making mistakes to reliable enough for daily use. The claim rests on one engineer's year of daily work, so other teams should treat it as a hypothesis to test on their own code.

Reality

Evidence30
Adoption
Insufficient
Hype gap+20
Incentives
Insufficient
Confidence35