Create your first visual prefab patch

This walkthrough changes a stock prefab in the Unity Inspector and produces a distributable patch manifest.

Before you start

You need:

  • a Redux mod project with the Redux SDK

  • ThunderKit configured for your KSP2/Redux installation

  • a Redux SDK Mod asset with a valid mod ID and an all-assets Addressables group

  • the external Addressables catalog available to the project

If the linked-asset browser cannot load its catalog, follow Set up the source catalog in the linked Addressables guide first.

1. Link the stock prefab

Open Modding → Linked Addressables → Open Browser….

Search for the prefab by address, label, or type. You can use t:GameObject to show only prefab-like GameObject entries. Select the entry, choose an output folder under Assets, and click Create Linked Asset.

The new asset looks like a normal Unity asset, but it keeps the stock Addressables identity. Do not unpack it or copy its source files.

2. Create the patch variant

In the Project window, right-click the linked prefab and choose Redux SDK → Create Prefab Patch from Linked Prefab.

In the window:

  1. Select the Mod asset that owns the patch.

  2. Enter a short patch name that is unique within your mod.

  3. Choose an output folder. The suggested location is Assets/<YourMod>/Patches/Prefabs.

  4. Leave Open variant after creation enabled.

  5. Click Create Patch.

The Redux SDK creates a prefab variant and a neighboring .prefabpatch.json manifest. The variant is the file you edit; the JSON is generated output.

3. Make a simple change

Open the variant and edit a serialized field in the Inspector—for example, a color, size, enabled state, or component setting. Save the prefab.

With Auto Compile On Save enabled, saving recompiles the JSON. Select the root's PrefabPatchAuthoringMetadata component to see the target address, operation count, last compile time, and any error.

4. Preview and test

Click Open Effective Prefab Preview in the metadata Inspector. The preview composes the current patch with other prefab patches available in the project.

Then build and deploy the mod through its normal ThunderKit pipeline and test the change in game. Use a campaign that has your mod on. A newly installed mod is off in campaigns. To turn it on, mark it under Default Features in the mods menu, or turn it on with Edit Pack. Check pm_summary.log if the patch is missing or rejected.

To apply the patch only with one of the features of your mod, list that feature under Required Features in the metadata Inspector.

Continue with Editing prefab variants before adding objects or references.