What problem does it solve? Writing Claude API code from memory often produces stale model IDs, deprecated parameters, and incorrect SDK usage across languages. This Skill provides authoritative, version-current reference for building applications with the Anthropic SDK, covering model selection, pricing, streaming, tool use, and agent patterns. ## Core Features & Use Cases - Multi-language SDK guidance: Language-specific documentation for Python, TypeScript, Java, Go, Ruby, C#, PHP, and cURL, with automatic language detection from project files. - Migration and upgrade workflows: Subcommands for model migration (migrate), prompt auditing (prompt-audit), SDK upgrades (upgrade), and cost optimization (cost-optimize). - Agent architecture patterns: Decision frameworks for choosing between single API calls, tool use workflows, Tool Runner, and Managed Agents. - Use Case: A developer asks to add streaming to their Python app. The Skill detects the language, reads the Python-specific reference, and generates code using claude-opus-5-5 with adaptive thinking and eager input streaming. ## Quick Start Use the claude-api skill to add streaming to my Python script that calls the Anthropic SDK.