LangGraph Control Flow and Iterative Agent Logic

Description

The source text explains the architectural foundation and control flow mechanisms of LangGraph, a framework designed for building sophisticated agent architectures. It details the use of the StateGraph paradigm, where computation is managed by Nodes updating a shared state, and Edges define the sequence of execution. The core primitives for managing workflow boundaries are discussed, including set_entry_point() and set_finish_point(), which define the start and end of the process, and add_edge() for fixed, sequential paths. Crucially, dynamic logic, iteration, and parallelism are implemented using add_conditional_edges(), which routes flow based on the output of a purely observational routing function. Finally, the text illustrates how these primitives combine to implement complex iterative patterns, such as the ReAct agent loop, and enable advanced features like error handling and multi-agent orchestration.