VSCodium is a community-driven, fully open-source binary distribution of Visual Studio Code (VS Code), built from the same open-source repository (Code-OSS) but without Microsoft's proprietary components.

The most used opencode plugins for VSCode have issues when installed in VSCodium except OpenChamber.

in the left sidebar select Extentions(Ctrl+Shift+X) in the search bar type OpenChamber and in the list press Install.

Now that the plugin is installed we set it up with the URL of the previously installed opencode server.

navigate to File → Preferences → Settings

In the window that opens, in the left pane expand >Exstentions and select OpenChamber

in the field Api Url enter http://localhost:4096.

Leave the Opencode Binary empty.

Test by pressing the cube like icon in the top right of the VSCodium interface.