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Overview

Interrupts are the core primitive for human-in-the-loop workflows. An interrupt:
  • Pauses execution by raising an Interrupt exception
  • Surfaces a payload to the caller (what you want a human/system to review)
  • Allows the workflow to be resumed later with a response value

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Raising an interrupt

Use interrupt(value) inside a step when you need input to continue. 
from coevolved.base.interrupt import interrupt

def require_approval(state: dict) -> dict:
    if state["amount"] > 1000:
        decision = interrupt({"question": "Approve?", "amount": state["amount"]})
        return {**state, "approved": bool(decision.get("approved"))}
    return {**state, "approved": True}
Keep interrupt payloads small and serializable. Treat them as UI/API-friendly messages, not full internal objects.

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Resuming execution

When an interrupt is raised, you typically:
  1. capture the interrupt payload (including its interrupt_id)
  2. ask a human (or another system) for a response
  3. resume by providing a value for that interrupt_id
Coevolved provides helper functions for setting resume values in context.

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Human-in-the-loop patterns

Common patterns built on interrupts:
  • Approvals / policy gates
  • “Review this draft” workflows
  • Manual tool execution steps
  • Escalation to an on-call / operator

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Next steps

Checkpointing

Persist state so you can resume long-running interrupted workflows.

base.interrupt reference

Interrupt types and resume helper APIs.