langchain-fundamentals

Guide developers in building LangChain agents with create_agent, tools, and middleware.

Updated Aug 27, 2026
One-click install
npx skills add https://github.com/HyunjunJeon/SDS-AX-Advanced-2026-1 --skill langchain-fundamentals-hyunjunjeon
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: langchain-fundamentals
Source: https://github.com/HyunjunJeon/SDS-AX-Advanced-2026-1/tree/main/Day-01/.agents/skills/langchain-fundamentals
Command: npx skills add https://github.com/HyunjunJeon/SDS-AX-Advanced-2026-1 --skill langchain-fundamentals-hyunjunjeon

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Streamlines building robust LangChain agents by guiding how to use create_agent(), integrate tools, and apply middleware for human-in-the-loop and error handling.

Core Features & Use Cases

  • Guides how to create agents with create_agent(), configure tools, and manage state.
  • Demonstrates middleware patterns for human-in-the-loop approval and error handling.
  • Shows how to define tools with @tool and tool() for Python and TypeScript.
  • Provides practical examples for production-grade agent workflows.

Quick Start

Create a LangChain agent using create_agent(), wire a simple tool, and apply human-in-the-loop middleware.

Frequently Asked Questions about langchain-fundamentals

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

FAQPage Schema
How do I create a LangChain agent with create_agent?

To create a LangChain agent, use the create_agent() function to configure agent state, wire tools using @tool or tool() decorators, and apply middleware for production-ready workflows. It guides setup across Python and TypeScript.

Does this guide show how to add human-in-the-loop approval for LangChain agents?

Yes, it demonstrates middleware patterns specifically for human-in-the-loop approval. You configure middleware within the create_agent() setup to intercept agent actions and handle HITL workflows safely across Python and TypeScript environments.

Can I use create_agent to manage state and define tools in both Python and TypeScript?

Yes, create_agent supports state management and tool definitions in both Python and TypeScript. You define tools using @tool or tool() syntax, allowing you to configure production-grade agent workflows consistently across both languages.

What is the best way to handle errors in LangChain agent workflows?

The best way to handle errors in LangChain agent workflows is by applying middleware patterns. These patterns enforce safe usage by providing clear structures for error handling alongside human-in-the-loop logic within your create_agent() configuration.

Why use middleware patterns when building LangChain agents?

You use middleware patterns to build robust LangChain agents because they enforce safe usage with clear structures for human-in-the-loop approval, error handling, and memory management. This streamlines production-grade agent configuration.