Elements

State

• The State is a shared data Structure that holds current information or context of an application.
• In simpler terms, it is application memory, keeping track of variables and data that notes can access and modify as they execute.

Node

• Notes are individual functions or operations that perform specific task within the graph
• Each note receives input (often the current state) processes it and produces an output or an updated

Graph 📊

• A graph in line graph in an overarching structure that maps out how different task (nodes) are connected and executed.
• It visually represents the workflow, showing the sequence and conditional paths between various operations.

Edge

• Edges are the connections between nodes that determine the flow of execution.
• They tell us which node should be executed next after the current one completes its task.

Conditional Edges

• Conditional Edges are specialized connections that decide the next node to execute based on specific conditions or logic applied to the current state.

Start 🏁

• The State node is a virtual entry point in LangGraph, marking where the workflow begins.
• It doesn't perform any operations itself but serves as the designated starting position for the graph's execution.

End 🔚

• The End nodes signifies the conclusion of workflow in LangGraph.
• Upon reaching this nodes, the graph's execution stops, indicating that all intended processes have been completed.

Tools 🛠️

• Tools are specialized functions or utilities that nodes can utilize to perform specific tasks such as fetching data from an API.
• They enhance the capabilities of nodes by providing additional functionalities.
• Nodes are part of the graph structure, while tools are functionalities used within nodes.

ToolNode

• A toolnode is just a special kind of node whose main job is to run a tool.
• It connects the tool's output back into the state, so other nodes can use that information.

State Graph

• A stategraph is a class in LangGraph used to build and compile the graph structure.
• It manages the nodes, edges and the overall state, ensuring that the workflow operates in a unified way and that data flows correctly between components

Runnable ⚡️

• A runnable in LangGraph is a standardized, executable component that species a specific task within an AI workflow.
• It serves as a fundamental building block and allowing for us to create modular systems.

Messages 📬

👨🏻‍⚖️ Human Message

• Represents input from a user.

💻 System Message

• Used to provide instructions or context to the model

🧩 Functional Message

• Represents the result of a function call

🤖 AI Message

• Represents responses generated by AI models

🔨 Tool Message

• Similar to Function Message, but specific to tool usage.