Little LUMI Model Build a module, ship it to the Workshop
Mods tab, file structure, behaviour additions, and the upload path — after patch 1.2.0.
Patch 1.2.0 (6 September 2026) turned Little LUMI Model into a moddable desktop companion. Mods can now add new behaviours and features, not only swap character images and voices. This guide covers the Mods tab in Settings, the file-based modding structure, and how to upload a module to the Steam Workshop for app 5075020.
This guide is for people who want to make content. To use community modules, start at the Modules Hub. To add Workshop characters without modding, use the Workshop guide.
The Mods tab
After updating to 1.2.0, open Settings and look for the Mods tab between Screen and About. The tab shows every mod you have running — both Steam Workshop subscriptions and manually added files — in a single unified list.
From the Mods tab you can enable or disable individual mods without unsubscribing from Workshop, drag items to change load order (higher items override lower ones when multiple mods affect the same behaviour), and see which mods are active, paused, or conflicting. If a mod causes unexpected animation or a freeze, drag it lower in the list or disable it. Load order matters when two modules define the same behaviour differently.
File-based modding structure
1.2.0 introduced file-based modding on top of the image and voice support that existed at launch. A mod lives in a folder inside the app’s mod directory. The exact path is part of what Studio LUMI documents on the Workshop and in official communication; this wiki will not invent a path Steam has not printed.
A typical mod folder contains a manifest.json that declares the mod name, version, author, and which behaviours or features it adds or overrides. The images/ folder holds sprite sheets or character image files that replace or augment Lumi’s default art. The voices/ folder contains audio files for self-talk lines, meeting chat, or custom sounds. The behaviours/ folder contains behaviour definition files that add new motion patterns or interaction responses. The manifest is the required piece; a mod with only images and voices works (this was possible before 1.2.0), but a mod with behaviours requires the 1.2.0 schema.
Making a character module
A character module is a sprite swap: you provide images that Lumi’s animation system reads as a new character, plus optionally voice files. Create a folder with a manifest.json declaring it as a character module, add image files to the images/ folder (name them to match the animation slots Lumi’s system expects), optionally add voice files for self-talk and meeting chat, test by placing the folder in the manual mod directory and checking it appears in Settings → Mods, then adjust load order so your character loads after any base sprites it depends on.
Workshop pages for existing character modules are the best reference for naming conventions and folder structure — subscribe to one, find it in the Mods tab, and study what the Workshop page states about the file layout.
Making a behaviour module
A behaviour module adds or overrides motion patterns. This requires the 1.2.0 behaviour schema. The manifest declares which behaviour slots the mod fills; the behaviours/ folder contains the definition files. Do not assume every behaviour slot is open. If two mods claim the same slot, load order in the Mods tab decides which wins. Test with your mod at the top of the list, then move it lower if conflicts appear.
Uploading to the Steam Workshop
Package your mod folder so it can be shared as a single unit (a zip or the folder itself). Go to the Steam Workshop for app 5075020, click Submit an Item, select LUMI Module, and follow the Workshop submission steps. Describe what the module does, what it requires (patch 1.2.0 for behaviour mods), and which behaviour slots it fills. Upload your packaged mod. The Workshop page becomes the subscription endpoint for people who want your character or behaviour. After approval, subscribers see your module in Settings → Mods the same way they see Workshop character subscriptions.
Modding safety
Always test a mod with the Mods tab visible so you can disable it quickly. Behaviour mods that override core animations can cause clipping or freeze the Settings window if they are malformed. Keep a clean Settings baseline open while testing. Do not share mods that copy or repackage Studio LUMI’s proprietary assets — character modules should use original art. If a mod breaks Lumi, disable it from the Mods tab first, then confirm the base pet still runs before posting a bug report.
Related pages
Subscribe community modules at the Modules Hub. Add Workshop characters using the Workshop guide. Call extra Lumi copies via Multiple Lumis. Character details are on the Lumi Hub. Modding is new after 1.2.0; this guide grows as Studio LUMI publishes the behaviour schema and the Workshop publishes example modules.
Frequently Asked Questions
Quick answers for new Little LUMI Model owners.
What does patch 1.2.0 enable for modders?
File-based modding, a Mods tab in Settings, and the ability for mods to add new behaviours and features — not only images and voices. Behaviour modules require the 1.2.0 schema.
How do I install a mod manually (without Workshop)?
After 1.2.0, place the mod folder in the app's mod directory. Open Settings → Mods to see it in the unified list. Fully restart Lumi for the folder to be read.
What is the mod folder structure?
A manifest.json is required. Then images/, voices/, and behaviours/ folders depending on what the mod adds. The exact directory path is in Studio LUMI's official Workshop documentation.
Can two mods change the same behaviour?
Yes. Load order in Settings → Mods decides which wins. Drag higher in the list to give a mod priority. Test carefully when behaviour slots overlap.
Where do I upload a mod I made?
The Steam Workshop for app 5075020. Select LUMI Module as the item type, describe what it does, and upload your packaged mod folder.