Extension for MELCloud Homey App

A Homey app extending the MELCloud app with automatic cooling adjustment based on the outdoor temperature.

Introduction

This app auto-adjusts the target temperature of your air-to-air devices — paired through either a MELCloud (classic) or a MELCloud Home account — to keep cooling within 8 °C of the outdoor temperature. Outdoor sources are picked per MELCloud building: the weather at your Homey's location, any temperature capability you like (useful when your units are not all in the same place), or nothing at all — new buildings start disabled, so the app never adjusts a device you did not opt in, and devices added to a building inherit its setting.

Why?

• Because it's better for your heat pumps.
• Because it's better for your health.
• Because it's better for the environment.

Usage

1. You must have a Homey Pro.
2. Install the MELCloud Homey app from the Homey App Store.
3. Pair your devices.
4. Install the MELCloud Homey app extension from the Homey App Store.
5. Configure the outdoor temperature source of each MELCloud building in the settings of the MELCloud Homey app extension.

Supported languages

Arabic, Danish, Dutch, English, French, German, Italian, Korean, Norwegian, Polish, Russian, Spanish, Swedish.

Development

Requirements: Node.js 22 (see .nvmrc) and the Homey CLI (npx homey).

npm ci               # install dependencies
npm test             # run the test suite (vitest)
npm run typecheck    # type-check with the native TypeScript compiler
npm run lint         # eslint (TS, HTML, CSS, JSON, YAML, Markdown)
npm run build        # bundle the settings page (esbuild) + native tsc compile
npm run homey:start  # run the app on your Homey (remote)

Architecture notes:

• The MELCloud dependency is wire-level, not npm: devices are reached through Homey's local API (homey-api), buildings through the MELCloud app's own API (app id com.mecloud), and every consumed shape is sanitized at entry so version skew degrades instead of failing.
• The settings page (settings/) is bundled by scripts/bundle.mts into a compat pair — a classic IIFE index.js (what the shipped HTML loads) plus an ESM twin index.mjs for phone-cached copies of the page (shipped bundle filenames are a compatibility contract) — emitted into .homeybuild, the packaged app, never into the source tree; npm run build produces them, and the Homey CLI runs it automatically on validate/publish.
• Both the build and npm run typecheck use the native TypeScript 7 compiler (typescript@7 aliased as @typescript/native) for speed; typescript@6 remains alongside it for tools that need the JS API (typescript-eslint).
• Test coverage is enforced at 100% for backend code; browser glue (settings/) is excluded from coverage.

Disclaimer

This app is not endorsed, verified or approved by Mitsubishi Electric Corporation. Mitsubishi cannot be held liable for any claims or damages that may occur when using this app to control MELCloud devices.

License

GPL-3.0-only