Human-in-the-Loop Agent Systems in Java

Fully autonomous agents make great demos. In production, someone on your team will eventually ask: "Can a human check this before it goes out?" The answer should be yes, and it shouldn't require bolting on a custom approval system. Human-in-the-loop isn't a limitation of agent systems -- it's a feature. The best agent architectures make it easy to insert human judgment at exactly the right points, without breaking the execution flow. This post covers how AgentEnsemble handles human review: the review handler API, review policies, pre-flight validation, and the patterns that make this work in practice. Why Human-in-the-Loop? Three reasons show up repeatedly in production agent deployments: Quality assurance. LLMs produce plausible-sounding output that's sometimes wrong. A human reviewer catches factual errors, hallucinations, and tone problems that automated checks miss. Compliance. Regulated industries (finance, healthcare, legal) often require human approval before AI-generated conten