Simple Calculator - Human in the Loop

Why it matters

A review control is only real when the answer changes what the workflow does next. This example puts a person’s yes or no in front of a decision to spend more of the agent’s execution budget.

What to practise

Run nat run with configs/config-hitl.yml. The custom retry_react_agent workflow hits a LangGraph recursion limit, and the reusable hitl_approval_function then asks, through the Toolkit’s user interaction manager, whether to proceed. Answer yes once and no once. Compare a retry with a higher max_iterations against a run that ends with a fallback result. Notice that the approval function comes from the POR to Jira example and is wired in through configuration, not coded into the agent.

How it fits

The two answers are the explicit transitions that 10.1.1 asks for: one resumes with a changed limit, the other stops. The run waits in the session for the reply, which is 10.1.2’s synchronous review; decide whether your own deadline could absorb that wait.