Context Engineering for RAG : The Four Typed Inputs Behind Every RAG Answer

The article introduces the concept of 'Context Engineering' for RAG, coined by Tobi Lütke and Andrej Karpathy in 2025. It describes how each document emits typed pieces that converge into a single LLM call, with corpus, conversation, and tool extensions as follow-up work. The piece focuses on the four typed inputs that shape every RAG answer.