--- id: introduction title: RAG Agent Evaluation Tutorial sidebar_label: Introduction --- import { ASSETS } from "@site/src/assets"; This tutorial walks you through the entire process of building a reliable **RAG (_Retrieval-Augmented Generation_) QA Agent**, from initial development to iterative improvement through `deepeval`'s evaluations. We'll build this RAG QA Agent using **OpenAI**, **LangChain** and **DeepEval**. :::note This tutorial focuses on building a RAG-based QA agent for an infamous company called **Theranos**. However, the concepts and practices used throughout this tutorial are applicable to any **RAG-based application**. If you are working with RAG applications, this tutorial will be helpful to you. ::: ## Overview DeepEval is an open-source LLM evaluation framework that supports a wide-range of metrics to help evaluate and iterate on your LLM applications. You can click on the links below and jump to any stage of this tutorial as you like: ## What You Will Evaluate **RAG (Retrieval-Augmented Generation)** agents let companies build domain-specific assistants without fine-tuning large models. In this tutorial, you'll create a **RAG QA agent** that answers questions about **Theranos**, a blood diagnostics company. We will evaluate the agent's ability on: - Generating relevant and accurate answers - Providing correct citations to questions Below is an example of what **Theranos**'s internal RAG QA agent might look like:. In the following sections of this tutorial, you'll learn how to build a reliable RAG QA Agent that retrieves correct data and generates an accurate answer based on the retrieved context.