The GenAI Stack is a prebuilt development environment for building support agents that utilize Generative AI (GenAI). It uses Docker, LangChain, Ollama, and Neo4j to create an integrated system. The stack includes tools like GraphRAG, which combines knowledge graphs with retrieval-augmented generation (RAG) to improve accuracy, relevance, and provenance in support agents. RAG is a technique that combines retrieval mechanisms with generative AI models to produce more accurate and contextually relevant responses. The GenAI Stack supports using open-source LLMs like Llama and Mistral instead of relying on third-party providers. An example support agent app demonstrates how the stack can be used to build a chat interface that queries an internal knowledge base, retrieves relevant information, and generates new questions in the style of highly ranked existing ones. The GenAI Stack allows developers to customize the code and configuration to suit their needs, making it easier to build and deploy GenAI applications.