LangChainAI & LLM

A library of composable abstractions for building LLM applications: model wrappers, prompt templates, output parsers, document loaders, text splitters, retrievers and agents that tie tools to a model. It also ships LangGraph for stateful, graph-based execution with cycles and human-in-the-loop steps, and LangSmith for tracing and evaluation. Most of it can be replaced by plain API calls — its value is in the connectors and the standardised shapes.