A standard edge (add_edge) is like a train track; the train must go there. A conditional edge (add_conditional_edges) is like a junction. The graph pauses, looks at the State, and decides which track to take. To implement this, we need a special Routing Function. This function doesn’t update the state; it simply returns the name … Read more
To fix the overwrite issue in lesson 1, we need to tell LangGraph: “When you receive new data for ‘topics’, do not replace the old data. Add it to the old data.” We do this using a Reducer. In Python, the operator.add function adds two lists together ([‘a’] + [‘b’] = [‘a’, ‘b’]). We can … Read more
In a standard script, you call function A, get the result, and pass it to function B. In LangGraph, you don’t call functions directly. You place them on a “board” (the Graph) and draw lines between them. The Graph manages the execution. The 4-Step Recipe Every LangGraph application follows the exact same 4-step structure: The … Read more