tl;dr: Anthropic's Claude Cookbook is a growing collection of practical guides and notebooks covering agent development, RAG, tool use, evals, multimodal workflows, and integrations. Recent entries emphasize the Claude Agent SDK and Managed Agents API, with tutorials on multi-agent orchestration, memory/context compaction, vulnerability detection, SRE incident response, and self-verifying agents. Older entries cover foundational topics like prompt caching, extended thinking, structured JSON extraction, and vector DB integrations.