LangGraph4j represents AI agent operations—LLM calls, function invocations, data transforms—as nodes in a directed graph, with edges modeling data flow. You create a graph, add nodes for chat, embeddings, external APIs or custom logic, connect them, and execute. The framework manages execution order, handles caching, logs inputs and outputs, and lets you extend with new node types. It supports synchronous and asynchronous processing, making it ideal for chatbots, document QA, and complex reasoning pipelines.