UE4SS-RE/RE-UE4SS

What it is

RE-UE4SS is a modding and scripting platform for games built on Unreal Engine 4 and 5. It injects into the game process and exposes the engine's object system to Lua and C++ mods, so mod authors can hook functions, read and edit runtime properties, and load blueprint mods without replacing game files. It also bundles dumpers for Unreal Header Tool-compatible headers, plain C++ headers with offsets, .usmap mappings for unversioned properties, and UMAP reconstruction data, plus a live property viewer/editor for debugging (feature list, live view).

It targets UE 4.7 through 5.8, but the authors explicitly do not aim for plug-and-play support of every game; per-game fixes, especially AOB signature updates, may be needed (version scope).

Quick start

The supported easy path is a prebuilt release, not a source build:

1. Download the latest non-experimental, non-dev zip from Releases.
2. Extract its contents into {game directory}/GameName/Binaries/Win64/ (installation steps).
3. If your game has a custom config entry, also extract that folder's contents into Win64.
4. Launch the game; UE4SS loads through the proxy DLL and Lua mods can be placed in the mods directory.

Mod developers should use the zDEV package instead. If installed via the proxy DLL, --disable-ue4ss launches the game without UE4SS, and --ue4ss-path <path> points at an alternate UE4SS.dll (command-line options). The UE4SS_MODS_PATHS environment variable adds semicolon-separated mod directories, with the first entry taking priority (environment variables).

Building from source is a separate, heavier workflow: clone recursively with submodules, link a GitHub account to Epic for the Unreal submodule, then configure with CMake using build modes such as Game__Shipping__Win64 (build commands). Full instructions are in the installation guide and the docs site.

Constraints

• Native builds require Windows and an MSVC toolchain supporting C++23 (MSVC >= 19.43, VS >= 17.13), Rust >= 1.73.0, CMake >= 3.22, and Ninja or MSVC (build requirements).
• Linux native builds are unsupported; Windows binaries can be cross-compiled from Linux with xwin or msvc-wine, which requires extra setup including Wine and binfmt_misc (cross-compilation).
• Game compatibility is not guaranteed; updating AOB signatures may be necessary for unsupported titles (compatibility guide).
• Modding/injection interacts with game binaries and anti-cheat or online services in ways this project does not address; check the specific game's rules before use.

HotRepo's take

The project has a recorded appearance on the daily C++ chart on 2026-11-02 at position 6, with 11 stars gained that day and 3,106 stars total. That single snapshot shows it remains visible in the C++ ranking, but it is not enough to establish a growth trend. The more substantive signal is the breadth of the toolkit itself—Lua and C++ mod APIs, dumpers, and runtime inspection in one injectable system—which explains its role as shared infrastructure for UE modding rather than a single-game mod.