Claude Opus 4.5
A variant of Anthropic's Claude Opus 4 series of models, intended for AI-assisted programming and complex engineering tasks.
Timeline (last 90 days)
In head-to-head user preference comparisons among early testers, 59% preferred Claude Sonnet 4.6 over Claude Opus 4.5.
The anti-fraud model that Coinbase fine-tuned from open-source Qwen3.5-9B beat Claude Opus 4.5 on its own risk-control benchmark.
The model outputs only a risk level (such as RISK_LEVEL: 5) with no explanation; under a prompt of about 7000 tokens, Opus's P50 latency is about 1.5 seconds.
Qwen3-235B performed the worst on injection tests, failing 5 out of 8 attacks; Gemini 3.7 Flash, Claude Haiku 5.5, and Claude Opus 4.5 achieved zero failures across all 8 injection attacks.
On strong models such as Claude Opus 4.5, DeReAct did not improve Pass@1 but made trajectories more evidence-complete and more compliant with constraints.
For Claude Opus 4.5, DeReAct's Pass@1 is roughly on par with the original ReAct baseline.
Claude Opus 4.5 and GPT-5.1 were released in November 2025, and paired with their respective coding agent frameworks (Claude Code and Codex), they evolved coding agents from frequently error-prone to reliable enough for daily use.
All Facts (7)
In head-to-head user preference comparisons among early testers, 59% preferred Claude Sonnet 4.6 over Claude Opus 4.5.
50%UnverifiedThe anti-fraud model that Coinbase fine-tuned from open-source Qwen3.5-9B beat Claude Opus 4.5 on its own risk-control benchmark.
50%UnverifiedThe model outputs only a risk level (such as RISK_LEVEL: 5) with no explanation; under a prompt of about 7000 tokens, Opus's P50 latency is about 1.5 seconds.
50%UnverifiedQwen3-235B performed the worst on injection tests, failing 5 out of 8 attacks; Gemini 3.7 Flash, Claude Haiku 5.5, and Claude Opus 4.5 achieved zero failures across all 8 injection attacks.
50%UnverifiedOn strong models such as Claude Opus 4.5, DeReAct did not improve Pass@1 but made trajectories more evidence-complete and more compliant with constraints.
50%UnverifiedFor Claude Opus 4.5, DeReAct's Pass@1 is roughly on par with the original ReAct baseline.
50%UnverifiedClaude Opus 4.5 and GPT-5.1 were released in November 2025, and paired with their respective coding agent frameworks (Claude Code and Codex), they evolved coding agents from frequently error-prone to reliable enough for daily use.
50%