Moontrader

Based on game build 714014 | Last updated: 2026-03-03

Overview

MoonTrader handles the logic for accepting or rejecting offerings made by other entities (typically players) to a moon trader entity (e.g., Moon Moth). It provides customizable validation (canaccept) and reward (onaccept) callbacks, manages item transfer/Consumption (including stack splitting), and ensures clean removal of the offered item upon successful acceptance. It is typically attached to trader or altar prefabs and integrates with inventoryitem, stackable, and gameplay state components.

Usage example

local inst = CreateEntity()
inst:AddComponent("moontrader")

inst.components.moontrader:SetCanAcceptFn(function(trader, item, giver)
    return item.prefab == "moonrock" and giver:HasTag("player"), "Must be a player holding a Moon Rock"
end)

inst.components.moontrader:SetOnAcceptFn(function(trader, giver, item)
    giver.components.inventory:GiveItem("moonlight_crystal")
    giver.components.sanity:DoDelta(20)
end)

Dependencies & tags

Components used: inventoryitem, stackable
Tags: Adds moontrader to the owning instance.

Properties

Property	Type	Default Value	Description
canaccept	function|nil	nil	Optional callback (trader, item, giver) -> (success: boolean, reason: string?) to validate offerings.
onaccept	function|nil	nil	Optional callback (trader, giver, item) -> nil to execute side effects after accepting an item.

Main functions

SetCanAcceptFn(fn)

• Description: Sets the validation function used to determine whether an offering is accepted. Called during AcceptOffering.
• Parameters: fn (function|nil) — A callback taking (trader, item, giver) and returning (success: boolean, reason?: string).
• Returns: Nothing.

SetOnAcceptFn(fn)

• Description: Sets the side-effect handler function, invoked after successful validation and item removal. Typically used to grant rewards.
• Parameters: fn (function|nil) — A callback taking (trader, giver, item).
• Returns: Nothing.

AcceptOffering(giver, item)

• Description: Processes an offering attempt. Validates via canaccept, splits or removes the item from the giver, invokes onaccept if provided, and deletes the item.
• Parameters:
  • giver (Entity) — The entity attempting to give the item.
  • item (Entity) — The item being offered.
• Returns: true on success; false, reason on rejection.
• Error states: Returns false, reason if canaccept returns a falsy result. Item is removed only on success; otherwise the offering remains unchanged.

Events & listeners

None identified.