ScreamAPI is a DLC unlocker for the games that are legitimately owned in your Epic Games account. It attempts to fool games that use Epic Online Services Software Development Kit (EOSSDK) into thinking that you own the desired DLCs. However, ScreamAPI does not modify the rest of the EOSSDK, hence features like multiplayer, achievements, etc. remain fully functional.

Only the games that use Epic Online Services Software Development Kit (EOS SDK) for the DLC ownership verification are supported. So if a game's installation directory does not contain any EOSSDK-WinXX-Shipping.dll files, then it's definitely not supported. Even if the game uses EOS SDK DLL, it's not guaranteed to be supported because each game might implement its own additional verification checks. Therefore, you have to first research the game's topic, to see if it supports unlocking.

Additionally, there are several points to bear in mind when it comes to ScreamAPI and Epic Games Store:

• ScreamAPI most definitely will not work with games that use 3rd party DRM, such as games from Ubisoft, Rockstar, etc. Furthermore, ScreamAPI is also unlikely to unlock anything in Free-To-Play games since they typically store all player data on the corresponding game server and hence all the checks are server-side.
• ScreamAPI will not work with games that employ additional ownership protection or if the game is using alternative DLC verification mechanism (like Borderlands 3). However, it can unlock DLCs in Denuvo-protected games if there are no other integrity checks (like Death Stranding)
• ScreamAPI is unlikely to work with games that use Anti-Cheat, since they typically detect any DLL/EXE that has been tampered with. Sometimes it is possible to disable an anti-cheat, but that typically entails the loss of online capabilities. Search in the respective game topic for more information about how to disable anti-cheat.
• Some games include the DLC files in their base game, regardless of whether you own the DLC or not (like World War Z). This is the ideal scenario for ScreamAPI. However, some games download additional files only after a user has bought the corresponding DLC (like Civilization VI). In this case, not only you will need to install ScreamAPI, but you also have to get the additional DLC files elsewhere and put them into the game folder.
• Some games don't use any DRM at all, in which case ScreamAPI is useless. All you need to do is to get the DLC files elsewhere and put them into the game folder.

Epic Games or a game publisher will obviously have the right to do so, as modifying game components is a violation of Epic Games store EULA. However, if you keep this to yourself, don't publicize your usage of it and don't try messing with games that have Anti-Cheats like BattleEye, Easy Anti-Cheat, etc. you should be fine. Either way, as mentioned in the license agreement of this project, I take no responsibility for the damages you might sustain. All I can say is that I have tried and used it in several games and have not been banned or punished in any shape or form.

In Proxy mode ScreamAPI DLL assumes the role of a proxy DLL that gets loaded by the game which thinks it has loaded the original DLL. ScreamAPI DLL in this mode will redirect most of the function calls to the original DLL. Kind of like how web proxy redirects requests to the original server. This is a classical, time-proven installation method that is stable, but has a number of shortcomings. The primary of them is that the unlocker binaries may be overwritten after a game updated, requiring re-installation of DLL. Another one is that some users don't feel like reading instructions properly, and just go ahead replacing the original DLL, instead of renaming it. Or they rename it incorrectly, for example by adding the number zero, instead of the letter o. Below are the instructions for the Proxy mode:

1. Find a file EOSSDK-Win64-Shipping.dll in your game's installation folder.
2. Rename it by adding 2 characters: _o (notice that it is a letter o at the end, not a numeral 0). In the end it should be named as EOSSDK-Win64-Shipping_o.dll.
3. Download the latest release zip from GitHub Releases. In case you have a hard time finding it, click on the Assets spoiler, then click on the link that looks like ScreamAPI-vX.Y.Z.zip
4. Open up the downloaded zip and unpack the EOSSDK-Win64-Shipping.dll file alongside the original EOSSDK-Win64-Shipping_o.dll in the game's binary folder.

In Hook mode ScreamAPI DLL is injected into the game process and dynamically patches the functions of interest in the original DLL, leaving the rest untouched. The unlocker DLL can be loaded automatically by exploiting DLL search order, which is what project Koaloader is used for. Koaloader DLL can be disguised as a system DLL, so that it can be automatically loaded by the game. In turn, Koaloader will load the ScreamAPI DLL. This has the advantage of not modifying any binary files on the disc, hence the unlocker will remain intact after updates. It should be also easier to install for some users. The only disadvantage is that Koaloader requires per-game setup. Below are the instructions for the Hook mode (in combination with Koaloader and its auto_load feature):

1. Download the latest ScreamAPI release zip from GitHub Releases.
2. Open up the downloaded zip, unpack the EOSSDK-Win64(32)-Shipping.dll and rename it to ScreamAPI.dll
3. Place the ScreamAPI DLL in game directory or any of its parent directories.
4. Download the latest Koaloader release zip from GitHub Releases.
5. Pick a DLL that is supported by the target game. In this example, we will select version-64/version.dll. Place this DLL in the game directory where a game first attempts to find a DLL, such as the game's binary directory.

You can also find an example setup here