langgraph-fundamentals

Model agent workflows as directed graphs with StateGraph nodes and edges.

Updated May 29, 2026

Search Tags:#workflow #routing #nodes #runtime #langgraph #stategraph #edges

Ready to run

npx skills add https://github.com/patorn/langgraph-template --skill langgraph-fundamentals-patorn

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: langgraph-fundamentals
Source: https://github.com/patorn/langgraph-template/tree/main/.agents/skills/langgraph-fundamentals
Command: npx skills add https://github.com/patorn/langgraph-template --skill langgraph-fundamentals-patorn

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

LangGraph enables developers to model agent workflows as directed graphs, unifying state, behavior, and routing into a single executable blueprint that is easy to debug and extend.

Core Features & Use Cases

StateGraph for building stateful graphs with START/END markers and reducers to merge state
Node and Edge constructs to define execution order, conditional branching, and parallel sends
Command and Send patterns for combining state updates with routing and fan-out
Compile-before-invoke workflow: ensure graphs are validated before execution; supports error handling and retry strategies
Real-world use: orchestrate multi-step AI tasks, manage complex control flows, and debug graphs in LangGraph Studio

Quick Start

Run a minimal graph that reads input, processes it, and outputs a result.

Frequently Asked Questions about langgraph-fundamentals

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I orchestrate complex agent logic using a LangGraph StateGraph?▼

LangGraph StateGraph orchestrates complex agent logic by modeling deterministic, branchable execution flows as directed graphs using structured nodes, edges, and robust state reducers to unify behavior and routing into an executable blueprint.

What is the best way to handle dynamic routing and parallel execution in LangGraph?▼

Dynamic routing and parallel execution in LangGraph are handled using Command and Send constructs, which combine state updates with routing decisions and fan-out tasks across multiple nodes simultaneously.

How does the compile-before-invoke workflow validate LangGraph execution?▼

The compile-before-invoke workflow ensures graphs are fully validated before runtime execution, supporting integrated error handling and retry strategies for both development and production environments.

When do I need state reducers to merge state in a LangGraph workflow?▼

State reducers to merge state in a LangGraph workflow are needed when building stateful graphs with START and END markers, ensuring that data updates from multiple nodes are correctly merged across complex execution paths.

Can I debug multi-step AI task control flows in LangGraph Studio?▼

Yes, you can debug multi-step AI task control flows in LangGraph Studio, which is designed to help manage complex orchestration and inspect stateful graph execution during development.