Claude Opus 4.5 is Anthropic's new flagship model in the Claude 4.5 family, and it's very clearly optimized around a single thesis: large language models are no longer just chatbots, they're operating systems for agents. It's positioned as Anthropic's best model for coding, agents, and computer use, and the design choices all point in that direction'long context, deep reasoning, powerful tool use, and strong safety scaffolding tuned for real work in spreadsheets, codebases, browsers, and enterprise workflows. At the core, Opus 4.5 is a large decoder-only transformer trained with next-token prediction on a broad mixture of internet text, code, documents, and synthetic data, continuing the Claude lineage. Anthropic doesn't publish layer counts or parameter numbers, but from its behavior and public documentation it's clear that the model combines high capacity with careful optimization for long contexts and tool-driven interaction. Within the 4.5 family, Opus sits above Sonnet and...
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