Anthropic is an AI safety and research company working to build reliable, interpretable, and steerable AI systems.

Anthropic

Claude Opus 4 is Anthropic's most powerful AI model released on May 22, 2025, positioned as the flagship model in the Claude 4 family and designed for the most demanding reasoning, coding, and long-horizon tasks. It represents the pinnacle of Anthropic's AI capabilities with the following key features:<ul><li>World-Leading Coding Performance: Claude Opus 4 is positioned as "the best coding model in the world». </li><li>Advanced Hybrid Reasoning: Claude Opus 4 is a hybrid reasoning model capable of both near-instant responses and extended thinking for deeper reasoning, with the ability to alternate between reasoning and tool use while maintaining "focused effort" across thousands of steps in complex workflows. When given access to local files, the model can extract and save "key facts to maintain continuity and build tacit knowledge over time».</li><li>Enhanced Memory and Context Processing: Claude Opus 4 dramatically outperforms all previous models on memory capabilities, becoming skilled at creating and maintaining 'memory files' to store key information when provided with local file access, unlocking better long-term task awareness and coherence. The model supports up to 64K output tokens and a 200K context window.</li><li>Enterprise-Grade Reliability: Anthropic has classified Opus 4 as a "Level 3" model on their four-point safety scale, indicating they consider it so powerful that it poses "significantly higher risk," requiring enhanced safety measures and evaluation protocols.</li></ul>Like all models of Anthropic, Claude Opus 4 was not specifically trained on specialized legal datasets, case law databases, or jurisdiction-specific legal materials. Despite its advanced reasoning capabilities and Constitutional AI foundation, research on AI constitutional interpretation reveals that AI systems make numerous implicit interpretive choices when analyzing legal texts, often making value-laden decisions "behind the scenes based on patterns in training data and the specific way questions are posed". Studies show that when AI systems interpret constitutional text, they make different implicit choices about interpretation methods—some taking literal approaches while others adopt purposive interpretations—precisely the kinds of choices human judges routinely make after careful deliberation. While Claude Opus 4's enhanced memory capabilities and extended reasoning may provide advantages in processing complex legal documents, the model may still lack deep understanding of legal precedent, statutory construction principles, and jurisdiction-specific procedural requirements.