ASI Plugin? DLL Scripts? Code Injection?

To both new and experienced users the abbreviations and acronyms used in GTA 5 modding can be overwhelming. Unfortunately many have never been properly documented. Some of the definitions below can't be 100% certified accurate but we will use our best guess as to what they stand for and of course what they mean.

What is an ASI plugin?

An ASI plugin is an external tool, generally C++, that can modify the game's code at runtime. The ASI loader tool for GTA 5 (dinput8.dll) loads the .asi files which contain custom-made modifications to the code. Using ASI plugins or mods, users can modify game mechanics, add new features, and change game behavior. These plugins are generally used to create custom mods for single-player games, and they are not allowed in online multiplayer games as they can lead to unfair advantages or cheating.

What does ASI stand for?

That's the $64,000 Question. Google searches don't provide any help and outside the inner community of experts who created these, what the acronym stands for is a secret. Here are some possibilities:

The ASI plugin for Grand Theft Auto games was originally developed by Alexander Blade. The letters ASI stand for "Additional Scripting Interface". Or does the SI part stand for Script Injector or Software Interface? Or is it Aggregate Script Interpreter?  

What is a DLL?

DLL stands for Dynamic Link Library. It is a type of file format in Microsoft Windows operating system that contains a collection of executable routines or code that can be called by other software applications. DLL files are reusable code libraries that contain modules that can be accessed by different applications and programs simultaneously.

DLL files help in reducing the size of software programs by sharing common functions that are used by multiple programs. By using dynamic linking, the DLLs are only loaded into memory when they are needed by an application, which results in efficient use of system resources. Most Windows applications, including games and system utilities, use DLL files to share common functionality. Developers who create software can also create their own DLL files to use in their programs.  

So How does this work in GTA 5?

Asi Mods are written in C++, compiled as regular dlls, but with the .asi extension. They are installed in the root folder. Examples are your Trainer and OpenIV.asi. Similarly, dll mods are mostly written in C# and most often installed in the scripts folder. Examples are mission and vehicle scripts. For those interested in creating asi mods, Alexander Blade offers an SDK (software development kit) on his Script Hook V site.

What does DLL injection mean?

DLL injection is a technique used in software engineering that allows an external program or code to be inserted, loaded, and executed within another process's address space. A DLL (Dynamic Link Library) can be injected into another process by developers to perform specific actions such as debugging, system monitoring, or adding new functionality in an application. The DLL injection process usually involves creating a remote thread in the target process, which then loads and executes the DLL code within the target process.