Hello,
I successfully created a new API_CompWallID API_Attribute using the DevKit, but how to set it's type (Slab, Wall, Roof) and put it in the correct folder (like the "Sols" folder for the slabs) ?
In the image, the created Attribute "Extended CompWall (API)" using the DevKit method.

Thanks
EDIT : I found how set the type of composite : "The flags field of the header describes whether this composite fill can be used for walls, slabs, roofs or shells (APICWall_ForWall, APICWall_ForSlab, APICWall_ForRoof and APICWall_ForShell respectively).". But I still can't find how create in subFolders.
Virone Lorenzo