Mega Tree API

FAQ

Symptoms, and what actually causes them.

My plugin does not load at all, and the log says nothing

This is the first thing to check in this game, and it is almost always one of two things.

Both fail silently: no exception, no line in the log, nothing in the plugin list. It reads exactly like a broken mod. Project setup has the csproj that works.

Nothing appears in the tree

Read the log. Open BepInEx/LogOutput.log and search for [api]. Every registration, rejection and reason is written there with your plugin guid.

An empty sub-tab is never drawn, and the Mods tab does not exist until a mod registers something - so if all your registrations failed, there is no tab at all, which looks like Mega Tree ignoring you.

BepInEx logs a duplicate guid error for MegaTree

Two copies of MegaTree.dll are installed - almost always because a mod shipped it inside its own folder. BepInEx loads one and drops the other, so the player may be running a different version from the one they installed. Set <Private>false</Private> on the reference and re-publish. Project setup

The node is there but does nothing

You registered it and never wrote the effect. Mega Tree stores a number; what that number means is always your code. Events covers the three shapes an effect can take.

The effect works, then stops

You are writing a field the game rewrites on its own schedule. Patch the getter instead - the game asks, you answer, and nothing can undo it. If there is no getter, re-apply on Apply, always computing from a remembered base value rather than adding to the current one.

I patched the getter and the timing did not change

Look for a cached WaitForSeconds. A coroutine that yields on an object built once keeps the old interval no matter what your getter returns - the duration was baked in when that object was created. Write the field holding it instead.

This is exactly what made Mega Tree's own cashier upgrade do nothing for a while, so it is not a hypothetical.

The effect grows forever

Apply runs about twice a second and you used +=. Compute absolutely: value = base * factor, never value += step. Details

The player's money went up (or down) twice as fast

You called AddSoftCurrency and notified ADD_SOFT_CURRENCY. In this game the event is the payment - EconomyManager subscribes to it and moves the balance. No game code calls the methods directly, and neither should you.

EventManager.NotifyEvent(EconomyEvents.ADD_SOFT_CURRENCY, bonus);   // this line alone pays

The icon is invisible, or the wrong colour

Mega Tree tints icons through Image.color, and tinting multiplies. Ship white artwork on a transparent background, or pass whiteSilhouette: true. A dark icon multiplied by anything stays dark. Icons

My node is locked forever

Your IsUnlocked returns false, or it throws - in which case the node is treated as unlocked and there will be a warning in the log naming it. Also check ComingSoon: that one can only be cleared by a mod update, never by the player. Requirements

A player says my node is grey and wants a store level

That is RequiredStoreLevel, and it only touches your node if you set it. If you never did, your node has no level requirement and something else is locking it - check IsUnlocked first.

Players can also turn the whole mechanic off with StoreLevelRequirements = false in BepInEx/config/MegaTree.cfg, and that ignores your requirement along with everyone else's. Node definition

Levels vanished after I updated my mod

You changed an id. The id is the save key: renaming it starts that line from zero and parks the old level in the kept block. Change the name, the price, the icon, the effect - never the id. If you must, list the old one in LegacyIds and the level comes with it. Versioning

A player uninstalled my mod and lost their upgrades

They should not have. Unknown ids are kept in the slot file under a comment and come back when your mod returns. If it really happened, ask for BepInEx/config/MegaTree/slotN.dat - it is plain text, and the kept block is at the bottom. Persistence

How do I change the sell-back rate for my node?

Set SellBackRate on your definition. It takes 0 to 1 and affects only your node - the built-in upgrades stay at 50%, and there is no player-facing setting for it.

SellBackRate = 0.8f,   // this node refunds 80%; everything else stays at 50%

Anything outside 0..1 is clamped, with a warning in the log. Above 1 the player would profit by buying and selling in a loop.

Straying far from 50% costs you something, though. Near 1.0 the upgrade becomes a piggy bank - buy to park money, sell when you need it, for free. Near 0 it punishes anyone who experiments. And a player looking at one node that refunds 90% next to one that refunds 50% has no way to know why. Use it when your line genuinely needs it, not by default.

Can I add my own top-level tab?

No. There are three fixed categories plus Mods, and everything registered through the API lives in Mods, in your own sub-tab. That is what keeps the header readable with ten mods installed. The Mods tab

Can I pick my node's colour?

No. The Mods branch is violet for everyone. A tree where each mod picks its own palette stops reading as one tree.

Can I read or change another mod's node?

You can read any level with MegaTreeApi.GetLevel, which is what gating on another mod is built on. You cannot change or unregister a node you do not own - Unregister checks the owner guid and returns false.

Can I give the player a level for free?

No. Levels change through the player buying or selling them, and that is deliberate: an API that could hand out levels would also be an API that could take them away, and both belong to the player. If you want a free effect, apply it in your own code without a node.

Is my code the same as a Tech Tree mod's?

The registration is, almost exactly - swap TechTree.Api for MegaTree.Api and the class names follow. The project is not: different target framework, different BepInEx, different base class, no Il2CppInterop. The API reference ends with a table of every difference.

Does registering many nodes slow the game down?

No. Lookups are dictionary-based, and Mega Tree measures its own per-frame cost into the log (search for [perf]) so you can check rather than guess. The 64-per-plugin limit is there to stop a runaway loop, not because 30 nodes would be slow.

Where do I ask something not on this page?

The Posts tab on Nexus. Include the [api] lines from your log - they usually contain the answer already.