Arcane

A code-first, test-native, agent-native 2D game engine.

Rust core for performance. TypeScript scripting for game logic — the layer AI agents write.

The Problem

Every major game engine — Godot, Unity, Unreal — was designed around one assumption: a human sitting in front of a visual editor. AI coding agents invert this. They are code-first, CLI-first, text-first. The mismatch is architectural, not just a tooling gap.

Arcane asks: "What would a game engine look like if it was built for an intelligence that thinks in text, operates at superhuman speed, but can't see?"

Core Principles

Code-is-the-scene. No visual editor. No .tscn files. Scenes, worlds, and entities are defined in TypeScript. Code is the source of truth.

Game-is-a-database. The entire game state is a queryable, observable, transactional data store. Not objects scattered across a scene tree.

Testing-first. Game logic runs headless — pure TypeScript, no GPU, no window. Tests execute instantly. The engine provides performance, not correctness.

Agent-native. A built-in protocol lets AI agents query game state, execute actions, "see" the game as text, and iterate at superhuman speed.

The Analogy

Rails for games. Rails didn't beat Java by being more powerful — it beat it by being opinionated and productive. Arcane doesn't beat Unity by being more capable. It beats Unity by being the engine an AI agent can actually use.

What It Looks Like

import { createGame, drawColorSprite, hud } from "@arcane/runtime/game";
import { rgb } from "@arcane/runtime/ui";
import { isActionDown, createInputMap, WASD_ARROWS } from "@arcane/runtime/input";

const game = createGame({ name: "my-game" });
const input = createInputMap(WASD_ARROWS);
let player = { x: 100, y: 100, score: 0 };

game.onFrame((ctx) => {
  // Input — action map handles keyboard + gamepad
  if (isActionDown("left", input)) player.x -= 200 * ctx.dt;
  if (isActionDown("right", input)) player.x += 200 * ctx.dt;

  // Render — sprites, shapes, text
  drawColorSprite({ color: rgb(60, 180, 255), x: player.x, y: player.y, w: 32, h: 32 });
  hud.text(`Score: ${player.score}`, 10, 10);
});

// game.ts — pure logic, no rendering, 100% testable
export function takeDamage(state: GameState, amount: number): GameState {
  return { ...state, hp: Math.max(0, state.hp - amount) };
}

// game.test.ts — runs headless, instant, no GPU
import { describe, it, assert } from "@arcane/runtime/testing";
describe("combat", () => {
  it("damage reduces hp", () => {
    const result = takeDamage({ hp: 10 }, 3);
    assert.equal(result.hp, 7);
  });
});

Target Games

2D games: RPGs, roguelikes, tactics, adventure, platformers. The sweet spot where agents can author everything except pixel art.

Target Audience

Solo devs building with AI agents
Game jam participants
Indie teams making 2D/2.5D games
Developers who code but aren't visual artists
Educational / hobbyist game dev

Quick Start

cargo install arcane-engine
arcane new my-game && cd my-game
arcane dev

Edit src/visual.ts, save, see changes in ~100ms. No restart needed.

Features

Rendering: Sprites, shapes, tilemaps, parallax, MSDF text, post-processing (bloom, CRT), custom WGSL shaders, 2D global illumination

Animation: Sprite sheets, state machines, transitions, blending, frame events

Physics: Rigid bodies, circle/AABB collision, joints, raycasts, sleep system (Rust-native)

Audio: Spatial audio, crossfade, bus mixing, pooling, pitch variation

UI: Buttons, sliders, checkboxes, text input, focus management, nine-slice panels

Input: Keyboard, mouse, gamepad, multi-touch, action mapping with buffering

Grids: Cartesian, isometric, hexagonal coordinate systems with pathfinding

Procgen: Wave Function Collapse with constraints (reachability, count, border)

Scenes: Scene stack, transitions (fade, wipe, iris), lifecycle hooks, save/load

Testing: Headless execution, snapshot replay, property-based testing, shrinking

Agent Protocol: MCP server (10 tools), HTTP inspector, describe/inspect CLI

CLI Commands

arcane new <name>        # Create project from template
arcane dev [entry.ts]    # Run with hot-reload + MCP server
arcane test              # Run all *.test.ts files
arcane add <recipe>      # Add a recipe (turn-based-combat, inventory, etc.)
arcane assets search     # Find free CC0 game assets
arcane assets download   # Download and extract asset packs

Recipes

Pre-built, composable game systems:

turn-based-combat — Initiative, attacks, victory detection
inventory-equipment — Items, stacking, equipment slots, stat bonuses
grid-movement — Grid-based movement with pathfinding
fog-of-war — Shadowcasting FOV, visibility states
actor-patrol — AI patrol patterns and waypoints

arcane add turn-based-combat

27 Demo Projects

Platformer, Roguelike, Breakout, Tower Defense, Card Battler, Sokoban, BFRPG Dungeon Crawler, Asteroids, Physics Playground, Isometric Dungeon, Hex Strategy, and more.

arcane dev demos/platformer/platformer-visual.ts
arcane dev demos/roguelike/roguelike-visual.ts
arcane dev demos/bfrpg-crawler/bfrpg-visual.ts

For AI Agents

Arcane includes an MCP server that works with Claude Code, Cursor, and VS Code. Tools: get_state, execute_action, step_frames, describe_game, run_tests, and more.

Scaffolded projects include:

AGENTS.md — Full development guide with working code patterns
types/*.d.ts — Per-module API declarations
types/cheatsheet.txt — Compact reference for 500+ functions

Status

v0.14.1 — 2253 TS (Node) + 2377 (V8) + 340 Rust tests passing.

Next: Phase 26 (Atmosphere). See roadmap.

Development

# Prerequisites: Rust 1.75+, Node.js 24+

cargo build --release           # Build
./run-tests.sh                  # TS tests in Node
cargo run -- test               # TS tests in V8
cargo test --workspace          # Rust tests
cargo check --no-default-features  # Verify headless

Documentation

Architecture — Two-layer design, Rust core, TypeScript runtime
API Design — Naming conventions, error handling
Recipe Guide — Building game systems with rule() and system()
Glossary — Canonical definitions for all terms
Roadmap — Development plan and backlog
Contributing — How to contribute (humans and agents)

License

Apache 2.0 — build whatever you want, commercially or otherwise. See LICENSE.

arcane-core 0.14.1