claude-sonnet-4-20250514

Claude Sonnet 4 sits within the Anthropic claude-sonnet family as a proprietary API-only assistant built for nuanced reasoning across coding, analysis, and creative tasks. Its lineage emphasizes long-context understanding and multi-step problem solving, making it well suited to complex workflows where coherent recall across extended documents matters. The model's design supports advanced reasoning for multi-step tasks and integrates tool-calling capabilities that enable agentic workflows where the assistant can invoke external functions to retrieve information or perform actions.

In practical use, the model combines a 200,000-token context window with a 64,000-token maximum output, allowing it to ingest and reason over large documents or codebases while producing substantial responses. It accepts text and image inputs, including PDF documents via attachments, and outputs text, which makes it flexible for mixed-media workflows such as document analysis, visual question answering, and code generation. Temperature control and structured output via tool calling round out a capability set aimed at developers building assistants, retrieval-augmented systems, and automated pipelines that require precise instruction following alongside strong analytical performance.