Retrieval-augmented generation (RAG) is an innovative approach to enhance the accuracy and personalization of large language models (LLMs) by integrating external knowledge bases, allowing these models to query and generate more precise outputs. This method is gaining popularity across various industries due to its cost-effectiveness and ability to improve AI system performance without requiring full model fine-tuning. The text explores different RAG tools, including experimental libraries like LangChain, LlamaIndex, and Haystack, as well as API-driven platforms like Merge and FinchAI, and enterprise-ready vector databases like Chroma and Pinecone. Fully-managed platforms such as Azure AI Search and Vertex AI Search provide comprehensive RAG systems with built-in security and scalability, while composable solutions allow for tailored AI workflows. The choice of RAG tools depends on factors like project goals, integration needs, available resources, and the desired balance between flexibility and simplicity, customization and speed, long-term scalability and short-term convenience, and internal control versus vendor dependency. Merge's Unified API is highlighted for its ability to connect AI models with external systems, facilitating faster integration, reducing maintenance burdens, and improving customer experiences by providing secure, real-time access to third-party data.