langchain-middleware
INVOKE THIS SKILL when you need human-in-the-loop approval, custom middleware, or structured output. Covers HumanInTheLoopMiddleware for human approval of dangerous tool calls, creating custom middleware with hooks, Command resume patterns, and structured output with Pydantic/Zod.
npx skills add majiayu000/claude-skill-registry --skill langchain-middleware-harmeet10000-skills --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
<overview> Middleware patterns for production LangChain agents: - **HumanInTheLoopMiddleware** / **humanInTheLoopMiddleware**: Pause before dangerous tool calls for human approval - **Custom middleware**: Intercept tool calls for error handling, logging, retry logic - **Command resume**: Continue execution after human decisions (approve, edit, reject) **Requirements:** Checkpointer + thread_id config for all HITL workflows. </overview> --- ## Human-in-the-Loop <ex-basic-hitl-setup> <python> Set up an agent with HITL middleware that pauses before sending emails for approval. ```python from langchain.agents import create_agent from langchain.agents.middleware import HumanInTheLoopMiddleware from langgraph.checkpoint.memory import MemorySaver from langchain.tools import tool @tool def send_email(to: str, subject: str, body: str) -> str: """Send an email.""" return f"Email sent to {to}" agent = create_agent( model="gpt-4.1", tools=[send_email], checkpointer=MemorySaver(), # Required for HITL middleware=[ HumanInTheLoopMiddleware( interrupt_on={ "send_email": {"allowed_decisions": ["approve", "edit", "reject"]}, } ) ], ) ``` </python> <typescript> Set up an agent with HITL that pauses b
- Human-in-the-Loop
- What You CAN Configure
- What You CANNOT Configure
What does the langchain-middleware skill do?
INVOKE THIS SKILL when you need human-in-the-loop approval, custom middleware, or structured output. Covers HumanInTheLoopMiddleware for human approval of dangerous tool calls, creating custom middleware with hooks, Command resume patterns, and structured output with Pydantic/Zod.
How do I install it?
Run `npx skills add majiayu000/claude-skill-registry --skill langchain-middleware-harmeet10000-skills --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From majiayu000/claude-skill-registry, a repository with 534 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.