MSS Docs

Megastore Simulator mod docs

Developer documentation for the Megastore Simulator mods I build. Pick a mod to start.

Mega Tree

Put your own upgrades in the Mega Tree

Mega Tree is an upgrade tree that lives on the store computer. Any BepInEx mod can register its own upgrade lines into it: you describe the node and write the effect, Mega Tree draws it, prices it, gates it, saves it per slot and translates it.

Read the Mega Tree API docs → Getting started API reference

Megastore is Mono. BepInEx 5, not 6.

This is the single most common reason a mod here does nothing at all. Supermarket Simulator is IL2CPP and takes BepInEx 6; Megastore Simulator is Mono and takes BepInEx 5. A plugin built for one never loads in the other, and the failure is silent - no error, no log line, nothing. Project setup has the csproj that works.

Straight to it

Getting started

Four steps from an empty BepInEx plugin to a node on screen.

Full example

A complete two-node mod with a gate and a real effect, ready to copy.

Code generator

Fill a form, get a compiling plugin and its cost table.

Validator

Paste a definition and see what Mega Tree would say about it.

API reference

Every public type, member and field, on one page.

FAQ

Symptoms, and what actually causes them.

Coming from Tech Tree?

The API is the same, name for name: ForPlugin, Register, UpgradeDefinition, the Mods tab with a sub-tab per mod, the same fourteen built-in icons. Your registration code ports almost unchanged - swap TechTree.Api for MegaTree.Api and it compiles.

What changes is everything around it, because the runtime is different:

	Tech Tree (Supermarket)	Mega Tree (Megastore)
Runtime	IL2CPP	Mono
BepInEx	6	5
Plugin base	`BasePlugin` + `Load()`	`BaseUnityPlugin` + `Awake()`
Target	`net6.0`	`netstandard2.1`
Game assemblies	`BepInEx/interop/`	`..._Data/Managed/`
MonoBehaviour	`ClassInjector` + `(IntPtr)` ctor	just a MonoBehaviour
Static fields	writing one crashes the game	safe

The mods

Mod	What it does	Docs
Mega Tree	Register your own upgrade nodes in the Mega Tree. Same API as Tech Tree, built for Mono - you describe the node and write the effect, Mega Tree handles the interface, buying, saving and translation.	Read the docs Nexus
Mega UI	Put your own app on the store computer. You describe the screen top to bottom and Mega UI does the icon, the window, the taskbar tab and the layout - no world-space maths, no RectTransform.	Read the docs

Are you a player, not a modder?

Then none of this is for you, and that is fine. These pages are about writing mods that plug into mine. If you just want to install and play, everything you need is on the mod page:

Mega Tree on Nexus Mods →

Reporting something

The Posts tab of the mod on Nexus is the fastest way to reach me. If it is about the API, include the [api] lines from BepInEx/LogOutput.log - they almost always name the cause.