The technology behind Warden

For the engineers, the self-hosters, and anyone who reads spec sheets before buying.

System overview

Warden is a three-component system: the Hub (central processor and Thread border router), Anchors (UWB + BLE sensors mounted in each room), and the Fob (a small key fob carrying your cryptographic identity).

The Hub runs a local policy engine that evaluates zone-entry events from Anchors and triggers automations via Home Assistant. Every decision is made on-premises in under 5 milliseconds. No data leaves your network.

Architecture diagram coming with production hardware photography.

Hardware specifications

Warden Hub

Processor ARM Cortex-A53
Radios 802.15.4z UWB, BLE 5.3, Thread (802.15.4)
Role Thread border router, policy engine
Cloud dependency None
More specs Coming with production hardware

Anchor Lite / Pro

UWB IEEE 802.15.4z, ±10cm ranging accuracy
BLE Bluetooth 5.3
Variants Lite (room detection), Pro (precision zones)
More specs Coming with production hardware

Warden Fob

Auth NFC-A (tap-to-identify)
Ranging UWB (passive zone detection)
Security Hardware secure element, on-chip key storage
Power NFC-powered (no battery)

Protocols

UWB (IEEE 802.15.4z)

Centimeter-accurate ranging for zone detection. Chosen over BLE-only because room-level presence isn't enough — we need to know where in the room you are to trigger zone-specific automations.

BLE 5.3

Room-level presence detection fallback. Lower power than UWB, wider compatibility. Used when centimeter precision isn't needed.

Thread (IEEE 802.15.4)

Self-healing mesh network for sensor data. Chosen over WiFi (too power-hungry) and Zigbee (Thread is IP-native and Matter-compatible). The Hub serves as the Thread border router.

NFC-A

Tap-to-identify for manual authentication. Also powers the Fob — no battery needed. The NFC field from your phone or an Anchor reader provides the energy.

Security model

Warden uses a zero-trust architecture. Every identity is cryptographically verified. Every policy evaluation happens locally. No implicit trust is granted to any device, network, or cloud service.

  • Each Fob has a hardware secure element with a non-extractable private key.
  • Keys are generated on-chip. They never leave the secure element — not to the Hub, not to any server.
  • The Hub evaluates policies locally. Zone-entry events are authenticated against the Fob's public key.
  • No over-the-air key extraction is possible. The secure element is designed to resist side-channel attacks.
  • Planned: open-source firmware for community audit of all security claims.

Home Assistant integration

Warden integrates natively with Home Assistant via a local API. No cloud bridge, no MQTT broker required (though MQTT is supported if you prefer it).

  • Presence sensors: per-person, per-zone presence entities
  • Zone triggers: automation events when a Fob enters or exits a zone
  • Identity events: who is where, for identity-aware automations
  • Local automation engine: <5ms latency from sensor event to action

How Warden compares

Comparison based on publicly available specifications. Verify independently before purchase decisions.

Feature Warden Ring SmartThings Philips Hue
Cloud dependency None Required Required Optional
Location precision ±10cm (UWB) Room (WiFi) Room (Zigbee) Room (BLE)
Crypto identity Yes (HW) No No No
Open firmware Planned No No No
Works offline Yes Limited Limited Yes
Subscription None Yes Optional Optional

Ready to take back control of your home?

Join the Waitlist