Create a human-in-the-loop tool using langchain's built-in humanInTheLoopMiddleware, which intercepts tool calls, sends approval requests, and resumes execution only after receiving user input (approve, edit, or reject).
langchain provides built-in humanInTheLoopMiddleware that intercepts tool calls before execution and waits for human approval[citation:4]. This middleware can be configured to require approval for specific tools only, while allowing others to run automatically. The human operator can approve (execute with original arguments), edit (modify arguments), or reject (provide a manual response) the tool call. This pattern is essential for sensitive operations like writing to a database, sending emails, or making payments where you want human oversight before execution.