From STEP Modding Wiki
How to use PSARCTool (by Lo2k)



PSARCTool is a tool created by Periander to uncompress .pak files to and from usual files and folder.
To simplify, .pak files are just another .zip format. It stores in one file several files and folders in a compressed form. This format as never changed since the initial release of No Man's Sky.
This means you can still unpak mods created for the very first version of the game !

Using PSARCTool

PSARTool is very easy to use :

  • just drag and drop any .pak file over it and it will decompress it into the contained files and folders.
  • just drag and drop any group of files and folders over it and it will compress them into a psarc.pak file.

Extracting all the game assets

If you want to start modding, the first thing to do is to extract all the .pak files.
The same way is used here : select all the .pak files from the game PCBANKS folder and drag them over the tool icon.

Be aware though that this will open as many instance of PSARCTool than there are .pak files !
This means you won't really be able to use your computer for a few minutes, the time all the game assets will be extracted.
Be also aware that you will need some free space on your hard drive as latest 2.61.1 assets occupy 24.1GB !

Warning-Logo.png      Warning:Beware : extracting all the .pak at once will occupy your CPU at 100% for some minutes and will fill about 25GB of your hard drive !

repacking a simple mod

For a mod, you often only edit a single file, or just a few of them.
If the file is a global, no problem as it is at the root of the extracted files.
But if it is nested inside some folders, it is important that the exact same folder structure will be kept and dragged over PSARCTool exe.
Moreover, you don't need all the other files around in each folder or subfolder, only the one(s) you edited for your mod.
So to prepare your mod, it's better to recreate the same folder structure before dragging it over PSARCTool.

For example :
You edited the REWARDTABLE.MBIN that was previously inside METADATA\REALITY\TABLES (You didn't edit it directly in the original folder, didn't you ?). Then to prepare your mod :

  • create a METADATA folder, enter it
  • (inside the MEDATATA folder) create a REALITY folder, enter it
  • (inside the REALITY folder) create a TABLES folder, enter it
  • copy or cut yoru REWARDTABLE.MBIN file inside this TABLES folder

Now you can go back and drag the METADATA folder over PSARCTool and get a clean and very small mod .pak file.

Possible issues

if a new mod doesn't work, it's often because the original folder structure is not respected.
to check it : unpak your .pak file. If you have extra folders before the game folders i.e. "My Documents\My project\METADATA" then you have to repak your mod.

This can be due because :

  • somewhere in the path you have some folders with uncommon characters. The best solution is to move your mod folders closer to the root of your hard drive, like in C:\ or on the desktop.
  • your files are nested inside so many sub folders on your computer than PSARCTool can't get the correct path. The best solution is to move your mod folders closer to the root of your hard drive, like in C:\ or on the desktop.