That is correct. The IDE is part of the old architecture and will be going away soon. Devices that show “placeholder” are now using edge drivers and are part of the new architecture. You can no longer make changes to them through the IDE.
non-technical answer: the IDE is part of the old groovy based architecture. It will be going away and be replaced with something else. in the meantime, anything which is using the new architecture will be represented in the IDE with “placeholder“ under the device type column. This includes devices using an Edge Driver. Since new edge drivers are being added overtime, it may even be that a device which is the same model number as a device you previously added which used a groovy DTH is now using an Edge driver and so shows up as placeholder.
Don’t change it! Once the device is using an integration from the new architecture, you can no longer get to its code details through the IDE, And changing it to a different device type may break the integration altogether.
Here’s the official announcement:
Beginning September 30, 2022, at 00:00 (PST) we will start migrations of Groovy device DTHs as well as SmartLighting and SevereWeather SmartApps, two of our most popular Smartapps built on Groovy. On October 15th 2022 certain functions of the legacy developer IDE, such as the creation of new DTH’s, Smartapps, and debugging tools will be removed from the SmartThings platform and will no longer be supported. After migrations are complete, this means that devices and automations previously using Groovy will now exclusively operate with our latest hub and cloud technology.
Recognizing trends within the smart home industry, SmartThings has been working diligently to evolve our platform into a modern REST API framework. Lua-based Edge drivers are a major step, which is being followed quickly w…
And the community FAQ
As of September 2023, SmartThings has now almost completed transition to a new architecture, part of which is called Edge.
The Samsung-hosted free groovy cloud gradually went away beginning on September 30, 2022. For hub-connected devices, including Zwave and Zigbee, the DTH replacement will be Edge Drivers, which are written in the Lua programming language and will run locally on your own hub.
IF YOU ARE NEW TO SMARTTHINGS
If you are new to SmartThings, the basics of the SmartThings architecture are pretty simple:
A) An “Edge Driver” is code that runs on your SmartThings/Aeotec hub so the hub can talk directly to an individual device. If you don’t have a hub, you can skip all the rest of this thread: it won’t apply to your setup.