lg-add

Extend LangGraph agents with HITL, persistence, streaming, and sub-agents.

4|Updated Apr 15, 2026
One-click install
npx skills add https://github.com/markhazlett/agent-harness --skill lg-add
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: lg-add
Source: https://github.com/markhazlett/agent-harness/tree/main/.claude/skills/lg-add
Command: npx skills add https://github.com/markhazlett/agent-harness --skill lg-add

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Enables teams to extend LangGraph agents with HITL, persistence, streaming, sub-agents, custom tools, middleware, and cross-thread memory, turning agent capabilities into production-ready workflows.

Core Features & Use Cases

  • Structured, phase-driven playbooks for adding capabilities to existing LangGraph agents
  • Supports hitting human-in-the-loop, durable state via checkpointers, streaming outputs, sub-agents, custom tools, middleware hooks, and shared stores
  • Generates tests, follow-ups, and concrete file paths to land changes in a real repo

Quick Start

Invoke lg-add with a capability (e.g., hitl) to augment an agent, then follow the prompts to specify the target graph and any required scaffolding.

Frequently Asked Questions about lg-add

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

FAQPage Schema
How do I add human-in-the-loop approval steps to a LangGraph agent?▼

You can add human-in-the-loop to a LangGraph agent by invoking a capability extension tool to select the target graph, switch on the HITL capability, and wire a checkpointer for durable state. This enforces a phase-driven approach for safe, auditable workflow interruptions.

What is the best way to set up cross-thread memory and persistence in LangGraph?▼

The best way to set up cross-thread memory and persistence in LangGraph is by wiring a shared store and checkpointer into your target graph. This enables durable state management and turns agent capabilities into production-ready workflows.

Can I integrate sub-agents and streaming outputs into existing LangGraph workflows?▼

Yes, you can integrate sub-agents and streaming outputs into existing LangGraph workflows. The extension process guides capability switching and generates test scaffolding, ensuring the new streaming and sub-agent features are safely wired into the target graph.

Does adding middleware hooks to LangGraph require rewiring the entire agent graph?▼

Adding middleware hooks to LangGraph does not require rewiring the entire graph. The process targets production-grade workflows by guiding target graph selection and capability switching, allowing you to layer middleware and custom tools without breaking existing logic.

How do I test LangGraph agent extensions like custom tools and middleware?▼

To test LangGraph agent extensions like custom tools and middleware, the augmentation process generates test scaffolding and concrete file paths. This ensures you can safely land changes in a real repo and validate middleware behavior through clear follow-ups.