Test and package a prefab patch

A prefab patch is ready to distribute when the compiled manifest is included in your mod's Addressables build and the linked stock assets are not copied into the mod.

Check the generated files

The prefab variant contains your authoring overrides and metadata. Its neighboring .prefabpatch.json file is the runtime patch manifest.

Select the root PrefabPatchAuthoringMetadata component and confirm:

  • the linked target address is correct

  • the owning mod is correct

  • the compiled manifest exists

  • the operation count is not zero unless the patch intentionally does nothing

  • the Required Features and Excluded Features lists are correct, if the patch belongs to one of your features

  • no compile error is shown

Use Compile JSON Now after changing metadata or when you want an explicit compile. Select Compiled JSON locates the generated manifest.

Check Addressables ownership

The Redux SDK places the compiled JSON in the owning mod's all-assets Addressables group and labels it with the mod's prefab-patch label. The default label is:

<mod-id>_prefab_patches

The mod's generated descriptor exposes that label as addressable_prefab_patch_label. You normally do not edit either value by hand.

The linked stock prefab is an authoring reference, not mod content. Do not add the linked asset to your mod's Addressables group and do not copy the game's bundles into your release.

Test in the editor

Use Open Effective Prefab Preview for a quick composition check. It catches missing targets, invalid references, stale prefab structure, and dependency problems without launching the game.

A preview proves composition, not the behavior of the instantiated prefab. Test the real feature in Play Mode or in a deployed build as well.

Test in game

Build and deploy the mod through the normal ThunderKit pipeline. Test in a campaign that has your mod and the features of the patch 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. Exercise the screen, part, effect, or system that instantiates the patched prefab.

Open pm_summary.log and find the Prefab Patches section. Use the part for the feature set of that campaign. Confirm that your manifest was discovered, the plan is valid, and the target prefab was composed. If it was rejected, the entry includes the patch and operation involved.

What to package

Package the normal output of your mod build:

  • your mod descriptor

  • your compiled assemblies, if any

  • your mod-owned Addressables

  • the generated prefab-patch manifest

Do not package linked descriptors as replacement stock assets, the linked preview objects, or any stock bundle copied from the game.