langchain-middleware

You can add human-in-the-loop (HITL) approval for specific LangChain agent tool calls by applying HITL middleware with per-tool policies. This allows you to configure custom middleware hooks to intercept, approve, edit, or reject dangerous tool calls before execution.

To persist state and resume LangChain agents after intercepting a tool call, you need a checkpointer for state persistence and Command-based resume semantics. These components enable safe tool usage by supporting interrupt, edit, and reject workflows across production agents.

Yes, you can configure custom middleware hooks to intercept and reject dangerous tool calls in LangChain. The middleware supports per-tool configuration, enabling you to enforce safe tool usage policies through command resume, editing, and rejection flows.

Yes, LangChain human-in-the-loop middleware works with both Python and TypeScript implementations. It enables per-tool HITL policies, hooks, and resume workflows across production agents in both languages, provided a checkpointer is used for state persistence.

Command-based resume semantics work for rejected LangChain agent tool calls by allowing the workflow to resume safely after human review. This mechanism integrates with the checkpointer to maintain state persistence during edit or reject flows for production agents.