Using Caelus API to Make Custom Wings or Gliders Actually Fly

If you are playing a pack where a mod adds wings, a glider, or some other flight item, and that item does nothing when you jump off a ledge, Caelus is the piece that makes it work. Here is how to get it functioning.

Make Sure Both Mods Are Present

Caelus alone will not give you flight. It only provides the shared system. You need the content mod that adds the wings or glider as well. If the content mod is installed but Caelus is missing, the flight item will typically be inert or the game will refuse to start. Install both, matching your loader.

Equip the Item Correctly

Most flight items need to be worn in a specific slot, usually the chest slot, or held in a particular way. Read the item's tooltip. If it says it grants flight, equip it where the tooltip implies, then jump from a height and press the jump key again mid-air to deploy. The exact deploy input depends on the content mod, so check its own documentation if the standard double-jump does not work.

When It Still Fails

If the item is equipped and nothing happens, the content mod may be checking a condition you have not met, such as having enough of a resource, being at a certain height, or not being in water. Caelus only answers the yes-or-no question of whether flight is allowed; the content mod decides everything else.