What is Human-in-the-Loop (HITL)?
An AI system design pattern where humans review or approve key agent decisions before they're executed.
Definition
Human-in-the-loop (HITL) is a design pattern for AI systems where certain actions or decisions pause for human review before execution. It's a middle ground between fully manual processes and fully autonomous AI. HITL is used when the stakes of a wrong action are high, when regulatory compliance requires human sign-off, or when output quality requires judgment that AI can't yet reliably provide.
Example
An email outreach agent drafts personalized emails for 50 prospects and pauses for a human to review and approve before sending. After approval, it handles all follow-up sequences autonomously. The human is in the loop for the first touch only.
Human-in-the-Loop (HITL) vs autonomous-agent: What's the difference?
An AI system design pattern where humans review or approve key agent decisions before they're executed.
An autonomous agent acts without human approval. A human-in-the-loop system pauses for human review at defined checkpoints — the right choice depends on the risk of the action.