Simplest Graphs using LangGraph Framework

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Basic Graph In LangGraph

To define a graph we need to create nodes and edges. In LangGraph we have 2 pre defined nodes Start and End that can be used in any graph and we need to create intermediate nodes.

These intermediate nodes are functions that are assigned a node name. After defining nodes we can define edges in following ways :

from langgraph.graph import Graph, START, END

g = Graph()

Add Node

In this case I am adding a node which is just a lambda that returns the same values as it accepted as an argument. So its a sort off a pass through function which can also be defined as

def f(x):

return x

g.add_node("do_somthing",lambda x: x)

Add Edges

We are adding two edges one from START node to do_something node and another from this node to end node.

g.add_edge(START , "do_somthing")
g.add_edge("do_somthing" , END)

Compile Graph

Next step is to compile graph which a sort of constructs graph based on nodes and edges above.

graph = g.compile()