Core Overview

The Oxide equivalent of this section is “Core”: commands + libraries. gregCore’s core is different — it is a client-side framework (no server, no chat commands, no permission groups). This page maps the framework’s architecture, services, logging, and configuration. Events and saves have their own pages: Core Events, Core Save Engine.

Boot sequence

MelonLoader
  → GregCoreMod.OnInitializeMelon          (src/gregCore.Main/Core/GregCoreMod.cs)
      → GregBootstrapper.Build(...)        (src/gregCore.Main/GameLayer/Bootstrap/GregBootstrapper.cs)
      → GregDirectoryPolicy / GregDoctor   (directories + self-diagnostics)
      → Service graph                      (GregServiceContainer, gregCore.Core)
      → UI Toolkit root                    (GregCanvasManager, GregUILayerManager)
      → SaveGuard install                  (GregSaveGuard, Harmony prefixes/postfixes)
      → Dynamic hooks                      (GregDynamicHookPatcher ← framework/greg_hooks.json + game_hooks.json)
      → Mod registry + language hosts      (GregModRegistry, GregLanguageRegistry: Lua/JS/Python/Rust/C#)

GregCoreMod (a MelonMod subclass) is deliberately thin: it exposes statics (Instance, PublicAPI: IGregAPI, HarmonyInstance, EventBus: GregEventBus, HookBus: GregHookBus) and forwards OnUpdate / OnSceneWasLoaded / OnApplicationQuit to the owners. All logic lives in the assemblies below.

Assemblies (`src/`)

Assembly	Role	Key types
`gregCore.Main`	Loader entry + composition root	`GregCoreMod`, `BuildInfo`, `GregBootstrapper`
`gregCore.Core`	Config, diagnostics, events, networking save DTOs, persistence, services, automation	`GregApiContext`, `GregServiceContainer`, `GregEventDispatcher`, `GregShop`, `GregServers`, `GregCoop`, `GregSaveGuard`, `GregEntityInventory`
`gregCore.Shared`	Cross-cutting utilities	`GregLogger`, `GregBanner`, `DevLog`, `GregFeatureGuard`
`gregCore.Abstractions`	Contracts only — the public API surface every other assembly references	`IGregEventBus`, `IGregLogger`, `IGregConfigService`, `IGregPersistenceService`, `GregModAttribute`, `GregHookAttribute`, `GregDependsOnAttribute`, `ModManifest`, `EventPayload`
`gregCore.UI`	Overlays, HUD, Mod Hub, click routing, panels, settings, keybinds	`GregPanel`, `GregPanelBuilder`, `GregMenuRegistry`, `GregMenuBinding`, `GregModHub`, `GregHud`, `GregHudRegistry`, `GregClickRouter`, `GregUILayerManager`, `GregSettingsHub`, `GregKeybindRegistry`
`gregCore.Bridge`	Stable static facade + native FFI (Go/Rust/Python/C#)	`GregAPI`, `GregPublicAPI`, `GameApiTable`, `NativeModLoader`, `GoFFIBridge`, `RustFFIBridge`, `PythonFFIBridge`
`gregCore.Hooks`	Dynamic Harmony patching + hook integration	`GregDynamicHookPatcher`, `HookIntegration`, `GregHookRegistry`, `SafePatch`
`gregCore.Patches`	Concrete game-specific Harmony patches	`HardwareIdPersistencePatch`, `IncompatibleModGuard`, `RackPatch`, `SaveSystemPatch`, `ShopPatch`, `PlayerPatch`, `TimePatch`
`gregCore.Mod`	C# mod base class + high-level modules + save/grid/wall systems	`GregMod` (abstract), `greg` (static: `Economy`, `Player`, `Server`, `UI`, `Save`, …), `GregGridManager`, `GregWallRegistry`, `GregSaveEngine`
`gregCore.SDK`	Author-facing multi-language SDK + Lua/JS hosts	`LuaFFIBridge`, `JsBridge`, `GregLuaHost`, `GregJsHost`, `Lua*Module` (~20 domain modules), `LuaRepl`, `LuaHotReload`, `GregHookCatalog`
`gregCore.Compatibility`	Legacy `DataCenterModLoader` shim + bundled QoL mods	`GameAPI` (`API_VERSION = 19`), `EventSystem`, `EntityManager`, `ModConfigSystem`, `greg.CommonShop`, `greg.QoL`, `greg.WallRack.Integration`
`gregCore.GameApi`	Generated Il2Cpp surface (~200 wrappers)	`GregGameModuleHost`, `Module` wrappers, `Generated/Il2Cpp/.g.cs` (via `tools/GameApiGenerator`)

Supporting pieces: src/GlobalUsings.cs, src/NullablePolyfills.cs, root gregCore.csproj (net6.0, deploys to the game’s Mods path), tests/gregCore.Tests, tools/, scripts/.

Services and context

GregApiContext bundles what a mod needs: Logger, EventBus, HookBus, Config, Persist, MainThread, Resources, Events.
GregServiceContainer wires the graph at boot; GregPluginRegistry + AssemblyScanner + GregDependencyResolver discover native (C#) mods.
GregPerformanceGovernor + GregOperationQueue + GregResourceMonitor throttle expensive work (scans, per-frame reflection) — see Developer Harmony IL2CPP and Developer Best Practices.
Automation engines (Automation, CableLaying, DeliveryZone, NetworkConfig, RackBuild, Repair) encapsulate repeatable in-game workflows for mods to call instead of reimplementing.

Logging and diagnostics

GregLogger (gregCore.Shared): Msg / Warn / Error / Debug / Section / PatchApplied / HookFired, plus per-mod GregModLogger. MoonSharp/Lua surface: greg.ui.log_info / log_warning / log_error / log.
DevLog for development-only chatter; MelonLoggerAdapter bridges to the loader log.
GregDoctor runs boot self-checks (directories, hook files present, incompatible mods). IncompatibleModGuard detects the old standalone 404-PersistentID mod and unpatches it so gregID stays the only ID system (log + one toast per session).
Directory policy (GregDirectoryPolicy): manual mods live directly in ./Mods, gregNative packages in ./Mods/gregNative, runtime libs in ./UserLibs, MelonLoader plugins in ./Plugins, data in ./UserData. A .deactivated folder next to a mod disables it — loaders never read from it; only gregCore moves files in/out on explicit user activation (GregModActivationService). Optional pack file Mods/manifest.json (Name/Mods/Library/Plugins, validated, .deactivated never loaded) additionally feeds dependency probing.
What to grep in logs: [gregCore], [gregCore][HwId], [DynamicPatcher], HWID SYSTEM ACTIVE.

Configuration

Framework config: GregConfigService.LoadConfig<T> / SaveConfig<T> (Newtonsoft.Json, MissingMemberHandling.Ignore, auto-creates directories). Debug flag: GregCoreConfig.DebugMode (default true in dev).
Mod settings (modern): GregModSettingsService + GregSettingsHub.RegisterTab with AddToggle / AddSlider / … builders; persisted in MelonPreferences.
Legacy mod configs: ModConfigSystem (RegisterBool / Int / Float, F8 panel, files under UserData/ModConfigs).
Entity inventory tuning: MelonPreferences category gregCore.EntityInventory (Enabled=true, VerboseLogging=false, DumpOnRebuild=false) with Dump() / Verify() — see Developer Hardware IDs Inventory.
Mod dependency declarations: GregModDeps (Declare / EnsureLoaded / CheckAll with minimum versions against the MelonLoader registry) + manifest diff (GetLocalManifest / DiffManifests / FormatDiff) for co-op mod-sync — see Developer Best Practices.

Compatibility notes

The old DataCenterModLoader API keeps working through gregCore.Compatibility (same GameAPI table, API_VERSION = 19, events re-emitted). New code should target the gregCore.Abstractions contracts / greg.* Lua API instead.
Rust FFI v7 Steam/P2P slots exist only as inert no-ops for ABI stability — the game owns networking (Developer Native Coop).
UI: IMGUI OnGUI is stripped in the IL2CPP build — always use UIToolkit via GregPanelBuilder (Developer UI Panels HUD).