Skip to content
Canon

Vol. VII · Protocols & Tools · VII.5

Humans as Tools

Factor 7: contact humans with tool calls. Approval, missing information, and exceptions are tools named ask_human, not a special control-plane myth.

5 min read

humanlayer/12-factor-agentslangchain-ai/langgraphcline/clineopenai/openai-agents-python

Doctrine

  • High-impact tools interrupt. The interrupt is a tool result the loop resumes on.
  • Ask questions as structured forms, not as chat waffle.
  • LangGraph's interrupt and Cline's approval gates are the same primitive.

The outer loop

Horthy's outer-loop agents meet people in Slack, email, tickets (Factor 11) and block on a human tool. Factor 6's pause/resume is how you do not lose the thread. If your 'human in the loop' is a console.prompt() in a batch job, you built a toy.

Anti-patterns

  • Auto-approving anything the model labels 'safe'.
  • HITL that cannot resume (email the human, lose the state).

Related