langchain-fundamentals

Build LangChain agents with create_agent, tools, and middleware.

Updated Apr 23, 2026
One-click install
npx skills add https://github.com/ladinglogichq/lading-logic-hackathon --skill langchain-fundamentals-ladinglogichq
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: langchain-fundamentals
Source: https://github.com/ladinglogichq/lading-logic-hackathon/tree/main/.claude/skills/langchain-fundamentals
Command: npx skills add https://github.com/ladinglogichq/lading-logic-hackathon --skill langchain-fundamentals-ladinglogichq

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Define and orchestrate production-ready LangChain agents by showcasing the canonical approach with create_agent, tool definitions, and middleware patterns.

Core Features & Use Cases

  • Creating agents with create_agent, integrating tools, and using middleware for HITL and robust flows.
  • Examples cover Python and TypeScript tool definitions, persistence with checkpointer, structured outputs, and middleware customization.
  • Use case: design end-to-end agent workflows that can search, reason, and act across domains with clear failure handling.

Quick Start

Create a simple LangChain agent using create_agent with a basic tool to observe the agent loop in action.

Frequently Asked Questions about langchain-fundamentals

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

FAQPage Schema
How do I build LangChain agents with create_agent in Python?

You build LangChain agents with create_agent by defining Python tool functions and passing them to the function to observe the agent loop. This canonical approach orchestrates production-ready agents that can search, reason, and act across domains.

What is middleware in LangChain agents used for?

Middleware in LangChain agents is used to implement human-in-the-loop (HITL) patterns and customize agent workflows. Adding middleware ensures robust flows with clear failure handling during end-to-end agent execution.

Can I define LangChain tools and structured outputs in TypeScript?

Yes, you can define LangChain tools and configure structured outputs in TypeScript. The Skill covers both Python and TypeScript examples for tool definitions, enabling cross-language agent workflows.

Do I need prior LangChain experience to use create_agent?

You need basic Python or TypeScript knowledge and exposure to LangChain patterns to use create_agent effectively. These prerequisites help you understand the tool definitions and middleware configurations demonstrated in the guide.

How do I add persistence to LangChain agents using a checkpointer?

You add persistence to LangChain agents by integrating a checkpointer within your create_agent configuration. This enables state management across interactions, supporting robust flows and clear failure handling for your agent workflows.

What's the best way to handle agent failures in LangChain workflows?

The best way to handle agent failures in LangChain workflows is by adding middleware for human-in-the-loop (HITL) interactions. This approach provides clear failure handling and ensures robust end-to-end agent flows across domains.