Spool plugin: player motion

player_motion is one of spool's more fully-realized plugins: a typed port of the published player_motion datapack, launching a player by decomposing a velocity vector into a 32-bit-per-axis score tree that an apply_impulse enchantment reads. It's a good example of the KitPlugin shape because its whole public surface is two small typed methods.

Installing the plugin

A plugin does nothing until it's installed. installKit adds its method to the shared Datapack prototype, once, ever:

import { Datapack, Selector, v26_2 } from "helix";
import { installKit } from "spool";
import { playerMotion } from "spool/plugins/player_motion";

installKit([playerMotion]);

const dp = new Datapack("mypack", v26_2);
const pm = dp.playerMotion();

Launching with a typed velocity

launchLocal takes a velocity relative to the player's facing - sideways/up/forward in blocks/tick - and must run positioned as the player:

dp.createFunction("launch/jump_pad").build((ctx) => {
  ctx
    .execute()
    .as(Selector.allPlayers())
    .at(Selector.self())
    .run((c) => pm.launchLocal(c, { up: 1.4, forward: 0.6 }));
});

launchGlobal is the same idea along world axes instead of facing-relative ones. Both have sustained per-tick counterparts - applyLocal / applyGlobal - for continuous motion (a thrust, a grapple arc) once a launch is already underway; the grapple plugin is built on exactly that primitive.

No macros, no hand-built NBT: the whole 96-effect enchantment (32 bits × 3 axes) and its predicates are generated resource JSON, driven entirely by the typed LocalVelocity/ GlobalVelocity interfaces.

See the spool guide for the plugin system in general, and the generated PlayerMotion API reference for the full method set.