Criticality Tiers

Every device declares a criticality tier in its /capabilities response. This determines how ZenEdge handles failures.

Tier Definitions

Tier	Guarantee	Failure Behavior
CRITICAL	Must work for the booking to succeed	Retry with grace period. Alert admin immediately. May block booking access.
STANDARD	Important but non-blocking	Booking proceeds. User notified of degraded service. Background retry.
OPTIONAL	Nice-to-have	Silently degraded. No user impact. Logged for review.

Examples

Device	Typical Tier	Rationale
Door lock	CRITICAL	Guest can't enter the room without it
Wi-Fi hotspot	STANDARD	Meeting can proceed without Wi-Fi
Ambient lighting	OPTIONAL	Cosmetic feature
Smart fan	OPTIONAL	Comfort feature
Camera	OPTIONAL	Monitoring only

Impact on Booking Access

When a booking.start event triggers magic link issuance:

1. ZenEdge checks health of all devices in the physical space
2. CRITICAL devices must be healthy — if not, retry logic activates
3. STANDARD devices are included if healthy, skipped with notification if not
4. OPTIONAL devices are included if healthy, silently skipped if not

Declaring Criticality

In the /capabilities response:

{
  "devices": [
    {
      "device_id": "ada-lock-001",
      "type": "lock",
      "criticality": "CRITICAL"
    },
    {
      "device_id": "ada-wifi-001",
      "type": "wifi",
      "criticality": "STANDARD"
    }
  ]
}

Next Steps

• Capability Discovery — Full capabilities schema
• Health & Heartbeat — Monitoring details