Getting Started

The Interposer works by injecting a DLL into a game process. Once loaded, it installs hooks on common Windows APIs and reads its configuration from files placed next to the DLL. No changes to the game itself are required.

What You Need

The DLL itself is placed next to the game executable. Runtime configuration lives in a .interposer\ subdirectory alongside it:

File / Directory	Purpose
LANCommander.Interposer.dll	The hook DLL
.interposer\Config.yml	Settings, file redirect rules, and FastDL configuration
.interposer\Registry.reg	Virtual registry initial state (only needed for registry emulation)
.interposer\Logs\	Session log files — created automatically, one file per session
.interposer\Downloads\	FastDL overlay cache — created automatically

A sample Config.yml is included in the release package with all options documented inline. You only need to enable or configure the features you want — every option has a sensible default.

Choosing a Deployment Location

The DLL is found relative to whichever directory the injector or host process loads it from. The simplest approach is to place all files next to the game's executable:

C:\Games\MyGame\
  game.exe
  LANCommander.Interposer.dll
  .interposer\
    Config.yml
    Registry.reg      ← only needed for registry emulation

The DLL locates Config.yml and Registry.reg inside the .interposer\ directory relative to its own path, not the working directory, so the exact placement of the game executable does not matter as long as the DLL and its .interposer\ subdirectory share a directory.

Injecting the DLL

Using the Injector

The LANCommander.Interposer.Injector.exe handles injection in two modes.

Inject into a running process by name or PID:

Injector.exe <process-name-or-PID> [dll-path]

Injector.exe game.exe
Injector.exe 1234
Injector.exe game.exe "C:\path\to\LANCommander.Interposer.dll"

Launch a game and inject before its first instruction runs (recommended — avoids race conditions on startup):

Injector.exe --launch <exe-path> [game-args ...] -- [dll-path]

Injector.exe --launch "C:\Games\MyGame\game.exe"
Injector.exe --launch "C:\Games\MyGame\game.exe" -fullscreen
Injector.exe --launch "C:\Games\MyGame\game.exe" -fullscreen -- "C:\path\to\LANCommander.Interposer.dll"

The -- separator is used to distinguish game arguments from the DLL path. If no DLL path is given, the injector searches its own directory for LANCommander.Interposer.dll or interposer.dll.

tip

Use --launch mode when possible. Injecting into a running process can miss hooks for API calls made during early startup, such as registry reads and file opens that happen before main().

caution

The injector and the game must match in bitness — a 64-bit injector cannot inject into a 32-bit process and vice versa. The injector will print a warning if a mismatch is detected.

Injecting from Another Application

Any process can inject the DLL by calling LoadLibrary with the full path to LANCommander.Interposer.dll from within the target process, or by using CreateRemoteThread(LoadLibraryW, ...) from an external process. The LANCommander client does this automatically when launching games.

Minimal Configuration

The smallest working .interposer\Config.yml is:

Logging:
  Files: true
  Registry: true

This enables access logging and leaves all other features at their defaults (file redirects disabled, FastDL disabled, borderless window always active). Logs are written automatically to .interposer\Logs\<timestamp>.log — no path configuration is needed.

Diagnostic Log

If the DLL fails to initialize — for example, because .interposer\Config.yml is missing or contains a syntax error — a diagnostic message is written to %TEMP%\interposer_diag.log regardless of any configuration. Check this file first if a game behaves unexpectedly after injection.