Guardian — anti-loop system

Automatic protection against runaway agents and duplicate traffic.

Guardian is HiWay's always-on safety net. It watches every request in near real time and blocks the three kinds of failures that bankrupt agent-heavy workloads: runaway loops, duplicate requests, and cost spikes.

The three rules

Rule	Trigger	Default action
Duplicate detector	Same prompt hash, same key, 3+ times in 60s	Block 4th request, alert
Cost spike	10× your 24h rolling average in under 5 minutes	Throttle to 1 req/s, alert
Zombie agent	Same key looping for 30+ minutes with no variation	Suspend the key, alert

Guardian is opt-out

Guardian is enabled by default for every account. You can tune thresholds per key in Dashboard → Guardian, or disable rules individually if a rule doesn't fit your workload. We strongly recommend keeping duplicate detection on — it has caught the vast majority of runaway agents we've seen.

What happens when Guardian blocks a request

Blocked requests return a 429 Too Many Requests with a specific error body indicating which rule fired. The cost of the blocked request is not debited — Guardian runs before the router decision and before the provider call.

json

{
  "error": {
    "message": "Blocked by Guardian: duplicate_detector (3 identical prompts in 47s)",
    "type": "guardian_block",
    "rule": "duplicate_detector",
    "retry_after_seconds": 60
  }
}