langchain-middleware

What problem does it solve?

This Skill provides essential middleware patterns for production LangChain agents, enabling human oversight for critical actions, custom processing logic, and structured output generation.

Core Features & Use Cases

• Human-in-the-Loop (HITL): Pause agent execution before dangerous tool calls (like sending emails or deleting data) to allow for human approval, editing, or rejection.
• Custom Middleware: Implement custom logic to intercept tool calls for error handling, logging, or retry mechanisms.
• Structured Output: Ensure agent outputs conform to predefined schemas using Pydantic or Zod.
• Use Case: An agent needs to send a customer-facing email. HITL middleware can pause execution, allowing a human to review and approve the email content before it's sent, preventing accidental miscommunication.

Quick Start

Use the langchain-middleware skill to set up an agent with human-in-the-loop approval for sending emails.