Keystone Utilities — 10 Systems: State Machine, Event Bus, Save System & More

State Machine, Event Bus, Save System, Object Pooling, Audio Manager, Input Manager & more — 10 decoupled, tested Unity systems. Drop in and ship faster.

• ✅ 10 complete systems — take only what you need, nothing else required
• ✅ Zero dependencies in the core systems — no third-party plugins; only the demo scenes need Unity's own UI package (already in most projects)
• ✅ Fully documented — a full manual with API tables and diagrams, plus an interactive demo scene for every system with real UI, buttons, and live stats panels
• ✅ Rigorously tested — every system passes a full EditMode + PlayMode regression suite before release
• ✅ Decoupled by design — no tangled cross-references between systems
• ✅ Extension points everywhere — swappable input backends, save serializers, audio/command/input middleware
• ✅ Editor-friendly — Inspector-configurable settings, tooltips on every field, clear console warnings instead of silent failures
• ✅ Own assembly definition — compiles independently, won't slow down your project's iteration times

480+ automated tests. Zero forced dependencies. Ten systems, take them one at a time.

Keystone Utilities is a toolkit of ten independent, production-ready systems covering the gameplay-programming groundwork almost every Unity project needs:

• 🧩 Event Bus — Systems communicate through typed events, not direct references — priority ordering, filters, one-shot subscriptions, deferred dispatch, interceptors, and event history for debugging.
• ⏪ Command Pattern — Execute/Undo/Redo, built in from the start — composite macros, sequential queues, cooldowns, and middleware, the backbone of RTS controls, editors, and replay systems.
• 🗂️ State Machine — Pause without losing gameplay state — push a state on top, pop it to resume exactly where you left off, with guarded transitions and automatic input/music context switching.
• ♻️ Object Pooling — Prewarmed, reusable instances — no runtime Instantiate/Destroy, hard caps, auto-expand, auto-return, zero allocation in your hot path.
• ⏱️ Coroutine Timer — Delay, repeat, and countdown timers that run from any plain C# class — no MonoBehaviour required.
• 🔊 Audio Manager — Centralized playback for every sound in the game — pooled SFX, cross-fading music, auto-persisted per-channel volume/mute, 3D and following sounds.
• 🎮 Input Manager — Named actions with contexts — live rebinding, mobile virtual axes, swipe detection, and a swappable backend for testing or new input systems.
• 💾 Save System — Multi-slot saves, production-ready from the start — version migration, autosave, a save-select-ready manifest API, JSON or lightweight-obfuscated binary.
• 🔒 Singleton<T> — The MonoBehaviour singleton base class — done once, correctly, with quit-safety and duplicate protection.
• 📄 Metadata Loader — One API for loading JSON, CSV, and XML from Resources, StreamingAssets, or disk — including the Android-safe async path everyone forgets.

Take only what you need. Most systems have zero dependency on anything else in the package — drop any one into a project alone. Exact per-system details are in the manual.

Every public method is covered in the included manual. Every system gets its own interactive demo scene — real buttons, live stats panels, no console-log spelunking required — plus a companion *_Examples.cs file behind it demonstrating every feature in code. A combined "Arena Survival" scene shows all ten systems working together in one small playable 3-wave combat loop.

Each system is a complete, production-ready tool on its own — not a stripped-down piece that only makes sense bundled with the rest. Use several together, though, and nothing feels bolted on: same Event Bus, same test suite, same conventions throughout, built and tested as one set rather than glued together after the fact. Whether you're prototyping a game jam entry or laying the foundation for a full production, the plumbing here is already done — alone or combined.

What's included

• Full C# source for all 10 systems (Assets/GameKit/Scripts), compiled into its own assembly
• A Hub scene plus an interactive demo scene per system, and a combined "Arena Survival" scene (Assets/GameKit/Demo)
• A full example script per system demonstrating every feature
• README.md quick-start guide, MANUAL.md full reference, and CHANGELOG.md version history