There are no node numbers. The node information you get from the interaction functions. But interactions are only tracked via an Update routine. There are no events currently at least that track interactions. A sample of my update routine that checks for interaction follows. But please note that I have noticed some flaws in the interaction results resulting in several checks before processing the information as valid.
Lua Code:
local playerInteracting = IsPlayerInteractingWithObject()
local interactMode = GetInteractionType()
if interactMode ~= INTERACTION_HARVEST then processingHarvest = false return end
processingHarvest = true
local action, name, blocked, extra, context = GetGameCameraInteractableActionInfo()
For say a mine (Iron Ore) the action would be "Mine" and the name would be "Iron Ore".
For a tree limb ( Maple ) the action would be "Cut" and the name would be "Maple".
For most others it is "Collect" or "Gather".
Occasionally however, I have had the "Use" of a crafting station show up as INTERACTION_HARVEST instead of a more appropriate interaction.