gregWiki/docs/reference/modding-language-requirement.md

id, title, slug, description

id	title	slug	description
modding-language-requirement	Modding language support	/reference/modding-language-requirement	Supported languages for mods, MelonLoader plugins, and extensions — C#, Lua, and Rust/native.

Modding language support

Supported languages

gregCore supports three modding languages through its Language Bridge system:

Language	Runtime	Mod location	Best for
C#	MelonLoader / .NET (direct IL2CPP interop)	Mods/*.dll	Plugins, deep framework extensions, performance-critical code
Lua	MoonSharp VM in LuaLanguageBridge	Mods/ScriptMods/lua/<modname>/	Gameplay mods, UI overlays, event-driven logic, rapid prototyping
Rust / native	FFIBridge (C ABI)	Mods/RustMods/*.dll or .greg	Native performance, existing Rust codebases

C# (primary)

All logic for MelonLoader plugins and framework extensions ships in C# (.NET compatible with MelonLoader). This is the traditional path and gives direct access to Harmony, IL2CPP interop, and all Unity APIs.

Lua

Lua scripts run inside gregCore's MoonSharp VM and interact with the game through the greg.* API:

• greg.unity.* — handle-based Unity object manipulation (FindObjectsOfType, GetComponent, Instantiate, TMPro, TextMesh, Transform, Material, Physics)
• greg.on() / greg.hook.before() / greg.hook.after() — subscribe to game events and Harmony patches
• greg.gui.* — IMGUI drawing (OnGUI)
• greg.io.* — file system access
• greg.input.* — keyboard input
• greg.config.* — key=value config files
• greg.color.* — hex color utilities

Lua mods are deployed as .lua files under Mods/ScriptMods/lua/. They do not require compilation or IL2CPP assemblies. gregCore discovers and loads them automatically.

Lifecycle: Lua scripts define optional global functions on_update(dt), on_scene(name), and on_gui() that gregCore calls at the appropriate Unity lifecycle points.

Example: FMF.HexLabelMod is a pure Lua mod (~300 lines) that uses greg.unity.* and greg.hook.* to add hex color labels to game objects.

Rust / native

Native mods (Rust, C, C++) are loaded by FFIBridge and communicate through a C ABI:

• mod_info() — returns mod metadata
• mod_init(api_table) — receives a GameAPITable with function pointers
• mod_update(dt) — called per frame
• mod_on_scene_loaded(name) — scene transitions
• mod_on_event(id, data, size) — game events (numeric EventIds)
• mod_shutdown() — cleanup

The RustLanguageBridgeAdapter fully delegates lifecycle calls to FFIBridge, including hot-reload support for non-DLL formats (.greg, .gregr).

Rationale

• C# remains the primary language because MelonLoader, Harmony, and IL2CPP interop are built around it.
• Lua lowers the barrier for mod authors who don't want to set up a C# build chain. The greg.* API handles all Il2Cpp bridging safely.
• Rust/native serves performance-critical use cases and mods already written in Rust.
• A single framework (gregCore) manages all three runtimes, keeping reviews, debugging, and CI consistent.

See also

• Repository architecture — language bridges and handle system
• Greg hooks & events — Lua event subscriptions
• System architecture & documentation principles — stack model
• Framework — runtime surface for mod authors