OpenSprinkler v3.4 (AC, US)

Quick verdict

Open-source controller with a fully local HTTP JSON API and a mature local HA integration, so the cloud is strictly optional. The open firmware exposes a local HTTP JSON API on your LAN and the HA integration uses it directly with no cloud server required. Just note: Wires into 24VAC valves - more involved than a hose timer.

Standout: Open-source controller with a fully local HTTP JSON API and a mature local HA integration, so the cloud is strictly optional.

Last checked: 2026-06-02

Compatibility snapshot

Why it stands out

• Open-source firmware with documented local JSON API; cloud is opt-in only
• Mature hass-opensprinkler integration; 8 zones expandable to 72
• Built-in weather-based watering on WiFi or wired Ethernet

Reasons to hesitate

• Wires into 24VAC valves - more involved than a hose timer
• No Matter/Thread; buy direct (no Amazon)
• Mid-tier price for the base controller

Best for

• DIY/HA users wanting a fully local, expandable, open irrigation controller

Avoid if

Privacy and local-control notes

The open firmware exposes a local HTTP JSON API on your LAN and the HA integration uses it directly with no cloud server required.

Home Assistant support: supported · integration path: hass-opensprinkler (HACS, local).

Buying reality check

Price notes: Around $160. Mid-range pricing.

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