LangChain Fundamentals

Create LangChain agents with create_agent, @tool, and middleware.

11|2|Updated Feb 3, 2026
One-click install
npx skills add https://github.com/jackjin1997/ClawForge --skill langchain-fundamentals-jackjin1997
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: LangChain Fundamentals
Source: https://github.com/jackjin1997/ClawForge/tree/main/skills/langchain-fundamentals
Command: npx skills add https://github.com/jackjin1997/ClawForge --skill langchain-fundamentals-jackjin1997

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill provides the foundational knowledge and practical examples for creating robust LangChain agents, enabling developers to build sophisticated AI applications.

Core Features & Use Cases

  • Agent Creation: Learn to use create_agent() for building agent loops, handling state, and integrating tools.
  • Tool Definition: Master the @tool decorator and tool() function for defining agent capabilities.
  • Middleware Integration: Understand how to use middleware for human-in-the-loop workflows, error handling, and custom logic.
  • Structured Output: Implement typed and validated responses from agents.
  • Use Case: Develop an agent that can search the web, perform calculations, and ask for user confirmation before executing a critical action.

Quick Start

Use the LangChain Fundamentals skill to create a basic agent that can answer questions using a provided tool.

Frequently Asked Questions about LangChain Fundamentals

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

FAQPage Schema
How do I build production LangChain agents using create_agent?

Build production LangChain agents using create_agent to manage agent loops, handle state, integrate tools, and configure persistence with checkpointers for robust AI applications.

What is the best way to define tools for LangChain agents?

Define tools for LangChain agents using the @tool decorator or tool() function to explicitly establish agent capabilities and structure their available actions.

How does middleware work for human-in-the-loop workflows in LangChain?

Middleware in LangChain works by intercepting agent flows to implement human-in-the-loop workflows, manage error handling, and execute custom logic for advanced control.

Can I implement structured typed responses with LangChain agents?

Implement structured typed responses with LangChain agents to generate validated and formatted outputs, ensuring predictable and structured output generation from agent interactions.

Do I need checkpointers to persist state in LangChain 1.0?

Checkpointers are needed to persist state in LangChain 1.0, enabling agents to maintain context across interactions and resume complex agent loops reliably.