TL;DR: RAG metrics fall into three categories. Retrieval metrics (hit rate, recall@k, MRR, nDCG) tell you whether the system retrieves the right chunks. Generation metrics (faithfulness, answer relevancy, correctness) tell you whether the LLM used them well. Operational metrics (cost, latency, storage) tell you if you can afford to run it. This guide explains each metric with an example and tells you which ones to focus on for your setup. There’s no shortage of RAG metrics. Libraries expose ...