Two-Way Device Sync

Blueprints Exchange
, , ,
1

Two-Way Device Sync

Open your Home Assistant instance and show the blueprint import dialog with a specific blueprint pre-filled.

This automation blueprint allows you to synchronize the state of any two binary entities (such as lights, switches, fans, and input booleans) mutually in both directions. Effortlessly mirror states between paired devices without writing complex YAML or worrying about cascading infinite loops.

Features

  • Bi-directional Syncing: Toggling either device on or off instantly mirrors the exact state to the other device.
  • Infinite Loop Protection: Utilizes Home Assistant context tracing (parent_id != this.context.id) to block self-triggering automation loops cold.
  • Smart Filtering: Automatically ignores attribute-only state updates and skips unnecessary action execution if devices already match.
  • Domain Agnostic: Dynamically handles multiple entity domains (light, switch, input_boolean, fan) on the fly using runtime variables.

Prerequisites

  1. Home Assistant Core: Ensure your instance supports modern blueprint syntax and action variables.
  2. Paired Entities: Two or more binary entities (light, switch, input_boolean, or fan) that you want to keep permanently synced.

Input Reference

Input Type Description
First Entity Entity Selector Select the first device, switch, light, or helper to synchronize.
Second Entity Entity Selector Select the second device, switch, light, or helper to synchronize.

Pro Tips

  • Decoupled Timers: If you want a countdown timer associated with your synced devices, keep the timer logic in a separate dedicated automation (or companion blueprint) so your sync layer stays lightweight and modular.
  • Multi-Way Control: Perfect for pairing smart plugs, virtual switches, or redundant wall switches that need to act as a single logical unit.

Acknowledgments & Credits

Special thanks to the Home Assistant community for documentation, context-tracing patterns, and architectural best practices regarding loop prevention in two-way device mirroring.

Installation

Method 1: Click to Import (Easiest)

Click the badge below to import this blueprint directly into your Home Assistant instance:

Open your Home Assistant instance and show the blueprint import dialog with a specific blueprint pre-filled.

Method 2: Manual Installation

  1. Download or clone the raw device_sync.yaml file from this repository. device_sync.yaml
  2. In your Home Assistant configuration directory, navigate to your blueprints folder (e.g., config/blueprints/automation/ufans123/home-assistant-blueprints/).
  3. Paste the code into a file named device_sync.yaml.
  4. Reload your automations or restart Home Assistant.

Method 3: Manual Installation using the Blueprints Dashboard (Easiest)

  1. Copy the following URL
https://github.com/ufans123/home-assistant-blueprints/blob/main/device_sync.yaml
  1. Navigate to your Home Assistant Blueprints Dashboard UI (Settings > Automations & Scenes > Blueprints).
  2. In the bottom right corner, click on the ‘Import blueprint’ button.
  3. Paste in the URL and follow the prompts.