Install the Modkit

The modkit contains the PAYDAY 3 development project and the tooling used to author mods.

Install the project

Obtain the current modkit release and extract or clone it to a writable development directory.

Avoid placing the project inside the PAYDAY 3 installation directory.

Complete the Wwise `ThirdParty` setup

Before building or opening the modkit, complete Set Up Wwise.

The modkit contains a modified Wwise integration based on Wwise 2023.1.15.8789.3579, but the Audiokinetic SDK libraries and other non-text ThirdParty files are not distributed with it.

Copy the required include and matching Windows x64_* SDK folders from your Wwise 2023.1.15 installation into:

<ModkitRoot>\Plugins\Wwise\ThirdParty\

Do not replace the bundled modified Wwise plugin with the stock Audiokinetic integration. Only restore the missing ThirdParty SDK payload as described on the Wwise setup page.

The modkit does not include a generated JMAP.

After downloading the modkit, there are two separate pieces of game data that must be refreshed for your installed PAYDAY 3 version:

AssetRegistry.bin, which is extracted from the game and placed in the modkit root so the editor can discover and load cooked PAYDAY 3 assets.
The JMAP, which is dumped from a clean running PAYDAY 3 process by GenerateJMAP.bat and is then used by Suzie to generate the modkit’s native class stubs.

AssetRegistry.bin is not an input to GenerateJMAP.bat.

Add the current `AssetRegistry.bin`

Complete Set Up FModel first. FModel must have the PAYDAY 3 AES key and a current local mappings file configured so it can reliably read the game archives.

Open FModel with your PAYDAY 3 installation selected, locate the game’s AssetRegistry.bin, and export the file using FModel’s raw file export/save functionality.

Copy the extracted file to the root of the modkit:

<ModkitRoot>/AssetRegistry.bin

The editor uses this asset registry to know which cooked PAYDAY 3 assets exist and which cooked packages it can resolve and load through the modkit’s cooked-asset workflow.

AssetRegistry.bin is an asset catalogue used by the editor. It is separate from both the FModel .usmap mapping file and the modkit JMAP.

You do not need to extract the game’s cooked assets into the modkit Content directory. The editor references the installed game’s cooked content rather than requiring redistributed copies of those assets.

Make sure AssetRegistry.bin comes from the same PAYDAY 3 version that you intend to mod.

Generate the JMAP

The JMAP is generated from the running game, not from AssetRegistry.bin.

Do this after downloading or updating the modkit, and repeat it after PAYDAY 3 updates so the reflected native game data stays in sync with the installed game version.

1. Prepare a clean PAYDAY 3 installation

Before generating the JMAP, temporarily remove or disable all PAYDAY 3 mods and UE4SS.

The JMAP should be dumped from an unmodified PAYDAY 3 process so the generated reflection data represents the stock game rather than classes or objects introduced or altered by runtime mods.

Do not generate the JMAP while UE4SS or other mods are installed and active in PAYDAY 3.

2. Start PAYDAY 3

Launch PAYDAY 3 with the clean setup and leave the game running.

GenerateJMAP.bat works against the live PAYDAY 3 process and runs the JMAP dumper on the running game.

3. Run `GenerateJMAP.bat`

With PAYDAY 3 running, run:

GenerateJMAP.bat

Follow any prompts printed by the script while it connects to the running game and dumps the current JMAP.

The generated JMAP is local generated data. It is not included with the modkit download, so this step must be completed on a new modkit installation before the current reflected game data is available.

Starting the Project

After installing wwise SDK, refreshing the JMAP, and updating the assetregistry.bin you can now load into the project.

At this moment, unreal engine will add some folders and a PAYDAY3.sln file to your base folder

If you encounter this error even after installing the wwise sdk in the "ThirdParty" folder in Plugins/wwise/

Plugin 'Wwise' failed to load because module 'Wwise' could not be found. Please ensure the plugin is properly installed, otherwise consider disabling the plugin for this project.

You need to open the .sln file in Visual Studio 2022 version 17.4+ with a C++ toolkit. Install this at this point if you do not already have these.

If a .sln file was not generated from the previous step, you can right click the PAYDAY3.uproject file > show more options > and hit generate Visual Studio project files.

After Visual Studio opens up, hit "build" on the top left > Build Solution

Wait for the solution to build. It should take about 3-5 minutes.

If you get a "Build Succesful" in the output log, then you are good to launch the project again.

Generate native classes with Suzie

The modkit uses Suzie to generate the native PAYDAY 3 class definitions used by the project.

Suzie consumes the generated JMAP and turns that reflected game data into the native class stubs exposed to the modkit. These generated types allow Blueprints and editor tooling to reference PAYDAY 3 native classes without requiring the original game source code.

You do not need to run UE4SS UHT generation for the modkit.

The modkit’s native class generation workflow is handled by Suzie using the JMAP. UE4SS UHT-generated headers are not required to set up or update the modkit.

UE4SS can still be useful for other runtime inspection, dumping, and reverse-engineering workflows, but its UHT generator is separate from the class-generation path used by this modkit.

After PAYDAY 3 updates

When PAYDAY 3 receives an update, refresh both pieces of game-derived data:

Make sure the installed game is on the version you intend to mod.
Use FModel to extract the updated AssetRegistry.bin.
Replace the existing AssetRegistry.bin in the modkit root with the new file.
Make sure PAYDAY 3 has no mods or UE4SS installed or active.
Launch the clean game.
Run GenerateJMAP.bat against the running game to dump a new JMAP.
Use the regenerated JMAP with Suzie so the generated native class data matches the updated game.

Keeping both files current is important for different reasons: AssetRegistry.bin keeps cooked-asset discovery in sync, while the JMAP keeps reflected native types in sync.

Expected components

A complete development setup includes the PAYDAY 3 project/stubs and the required modding plugins, including CrimeForge and Suzie.

Depending on the distribution, compiled plugin binaries may already be supplied. Source-based setups may require a project/plugin build before the editor can open successfully.

Do not copy game assets into the project

Do not populate the project by extracting PAYDAY 3 cooked assets into Content.

The cooked-asset workflow uses the user’s installed PAYDAY 3 content as read-only reference data. Your project should contain modkit content and assets you own or are permitted to redistribute.

Next: Set Up the Project.