I recently taught a course that focused on Unity. Now I have dozens of repositories that I need to take a look at. I don’t particularly like the Unity Hub, but as far as I know, I still need to use it anyway.

So, how do I get all these projects in there?

Surely, UnityHub must store its project list somewhere.

$ ps -ef | grep -i unity

This gives me a couple of unity processes that are running on my system. I’m simply choosing the first from that list, in this case, it’s process ID 143607. Your number will vary.

Next, let’s see what files this process has open.

$ lsof -p 143607 -a /home

Make sure to replace the process ID with the one you found earlier! This will give us a list of all open files in our home directory. This tells me where the this particular setup stores its configuration. For me, this is /home/<username>/.var/app/com.unity.UnityHub/config/unityhub.

I hope that this is stored in a relatively simple way, and since this whole structure is just 22MB on my disk, I just decide to grep through ALL OF IT with a name that I know must be in there somewhere.

$ grep -lr Example-Project
logs/info-log.json
projects-v1.json

Two files contain that name! Both of them are JSON, so after looking at them, I now know that projects-v1.json must be, where that UnityHub-List comes from. It contains Entries like these

$ jq . projects-v1.json
{
  "schema_version": "v1",
  "data": {
    "/home/<username>/Example Project": {
      "title": "Example Project",
      "lastModified": 1739361302837,
      "isCustomEditor": false,
      "path": "/home/<username>/Example Project",
      "containingFolderPath": "/home/<username>",
      "version": "2022.3.53f1",
      "architecture": "x86_64",
      "changeset": "abcdef",
      "isFavorite": false,
      "localProjectId": "f1677218d0c2cf8018498b4019580b73",
      "cloudEnabled": true
    }
  }
}

This is very straightforward. The entries in data are plentiful. The only thing I worry about is the localProjectId. Let’s see if I can just provite whatever I want in there, or if this can be found in the actual project somehow:

# (in the related project directory!)
$ grep -lr f1677218d0c2cf8018498b4019580b73
ProjectSettings/ProjectSettings.asset

Ok, so it is also stored in the ProjectSettings. It is part of

%YAML 1.1
%TAG !u! tag:unity3d.com,2011:
--- !u!129 &1
PlayerSettings:
  m_ObjectHideFlags: 0
  serializedVersion: 26
  productGUID: f1677218d0c2cf8018498b4019580b73
  AndroidProfiler: 0
# ... and so on ...

Let’s see if that matters? I modify the ProjectSettings.asset file to be something else. I also change the projects-v1.json to totally remove that localProjectId. After reopening UnityHub, the project is still in the list and it opens up just fine. Great, let’s just ignore this part! Also, the

So, all I need to do now is create that JSON structure from a bunch of directories I have on my drive. Sadly, writing a desired unity version in there does not get applied, you still will need to select it from a dropdown, because apparently UnityHub reads the information from the project instead.

Right now, you also need to integrate the output of my script into the existing JSON manually, but I will probably not change that. It’s a relatively rare occasion where I need to do that and that file’s structure is very simple.

So, this script now lives in my university-automation repository under Unity-United. If this is something you might need, feel free to give it a try!