Summary #

The GHL API is a local, open protocol that lets home and building automation systems read data from ProfiLux and Mitras devices, write setpoints, and trigger functions such as feed pause or water change. This article gives a short overview — the full technical reference, terms of use, and the option to enable API access are available on the GHL API page.

Applies to #

• ProfiLux 4 Series (incl. Industrial Line / IL) (min. firmware 7.31)
• Mitras LX8 Series
• Mitras LX7 Series (incl. Industrial Line / IL) (min. firmware 1.13)

Overview #

The GHL API gives external software direct, local access to your ProfiLux and Mitras devices. In broad terms, it lets you:

• Read device data: Sensor values (temperature, pH, redox, conductivity), KH Director and ION Director readings, switch channel states and load current, dosing pump fill levels, and flow/level sensor states.
• Write setpoints and names: Change target values for sensors, KH Director, and ION Director, and update the names of sensors, switch channels, dosing pumps, and other resources.
• Trigger functions: Start or stop feed pause, water change, and maintenance mode; activate light scenes and thunderstorm simulation.
• Stored measurement history: Retrieve previously logged sensor values, not just the current reading.

How it works #

• Local connection: The API runs entirely on your local network over a plain TCP port. No cloud service or account is required.
• Plain text commands: Only two command types exist — GET to read a value and SET to write one or trigger an action. Example: GET SENSOR[0] ACTVALUE[0] returns ACK <24.412>.
• Read-only or full access: The API is disabled by default. When you enable it on the device, you choose between read-only access or full read/write access.
• Your existing regulation keeps running: The API can read values, write setpoints, and trigger specific functions — but the ProfiLux’s own control loops, such as switching a heater based on temperature, continue to run on the device itself, independent of the API connection.

System Requirements #

• Device firmware: ProfiLux 4 Series requires min. firmware 7.31; Mitras LX7 Series requires min. firmware 1.13. Some newer features require more recent firmware — check the GHL API page for the current minimum per feature.
• Network module firmware: Requires an ESP WiFi network module with firmware 7141 or higher. If the API is unreachable despite correct network settings, update the network module firmware — see Firmware Update & Recovery.
• Local network: The device must be reachable on your local network — see Network (LAN & WiFi) – Setup Guide.

Example / Use case #

A common use case is showing aquarium values on a home automation dashboard alongside the rest of the building’s technology — for example, temperature, pH, and KH next to the heating and lighting controls, with sensors and outlets labeled with the same names configured in GHL Connect or GHL Control Center. Ready-made examples for Home Assistant and Python are provided on the GHL API page.