@tikron/sim

Isomorphic movement math for Tikron — the deterministic step and validation model shared by the server room and the client predictor. Run the same function in both places and they agree, which is what makes client-side prediction reconcile cleanly against a server-authoritative room. Zero dependencies.

npm i @tikron/sim

Shared step, authoritative check

import { stepToward, validateMovement, type Vec2 } from "@tikron/sim";

// Move `pos` toward `target`, capped by maxSpeed (px/s) over dt (ms).
// Call this on the client to predict AND on the server to advance — same result.
const pos: Vec2 = { x: 0, y: 0 };
const target: Vec2 = { x: 100, y: 0 };
const moved = stepToward(pos, target, 200, 16); // ≈ { x: 3.2, y: 0 }

// Server-side: reject a client-claimed position it could not have reached this frame.
const check = validateMovement(pos, { x: 999, y: 0 }, { maxSpeed: 200 }, 16);
// check.rejected === true; check.position is the clamped authoritative point

Because stepToward and validateMovement share one speed budget, a client that predicts with stepToward will never be corrected for legitimate movement — only for teleport-style cheating.

Key API

stepToward(pos, target, maxSpeed, dtMs) → Vec2 · validateMovement(prev, requested, config, deltaMs, tolerance?) → { position, rejected } · types Vec2, MovementConfig, MovementResult.

Links & license

tikron.dev · AGENTS.md. Licensed under the Tikron License 1.0 (adapted from FSL-1.1) — converts to Apache-2.0 one year after each release. See LICENSE.