MineXLauncher/resources/addons/jetpack.js

ModAPI.require("player"); //We need to add vertical velocity var jetpackActive = false; //Variable to track wether or not the jetpack is active window.addEventListener("keydown", (event) => { //When a key is pressed if (event.key.toLowerCase() === "h") { //If the key is h jetpackActive = true; //Set jetpack to be active } }); window.addEventListener("keyup", (event) => { //When a key is released if (event.key.toLowerCase() === "h") { //If the key is h jetpackActive = false; //Set jetpack to be inactive } }); ModAPI.addEventListener("update", ()=>{ //Every client tick if(!jetpackActive){ //If the jetpack is not active return; //Exit } ModAPI.player.motionY += 0.2; //Add 0.2 to the players vertical moition ModAPI.player.reload(); //Push changes });