Items on transport belt are not organized into inventories, they are organized into transport lines, each containing item stacks. You can query amount of transport lines given transport belt connectable has through LuaEntity::get_max_transport_line_index() (this time there are no gaps and all ...

I am trying to understand the function of LuaEntity#connected_rail_direction. I have these four train stops:

Screenshot 2026-05-12 at 11.00.52.png

All four report a connected_rail_direction of "0" (which is defines.rail_direction.back). Under which circumstances would a train stop report defines ...

I think I get what you are saying. Basically, it should be

prototypes.get_item_filtered { { filter = 'type', type = 'fuel' }, } and not prototypes.get_item_filtered { { filter = 'fuel' }, }

That makes me curious why the second form worked at all.

https://lua-api.factorio.com/latest/cla ... m_filtered states
However, within the debugger I get
because the correct field name is 'filter', not 'filters'

Hi,

I am trying to implement undo/redo for config changes for a custom mod based on a combinator. Currently, I am experimenting with serializing my custom configuration into a json string and store it in combinator_description/player_description. According to various posts here, there seems to be ...

I noticed that you can call e.g. LuaEntity.get+filter() or LuaEntity.get_or_create_control_behavior() on an entity ghost representing an inserter and it returns the information associated with it.

Is that intentional / officially supported or some undocumented behavior that might go away at any ...

Thank you for fixing the docs. However, I have to admit that there are a lot of places that could have benefitted from consistency (this being one of those). I have a lot of these small translation tables (in this case 'xxx-yyy' to 'xxx_yyy') in my mods and that leads to code duplications and the ...

This is an issue with docs and as such i am moving this to Documentation improvement requests.

Specifically the SpoilPriority refers to a concept in lua where `_` is used, however spoil_priority for inserter inside of BlueprintEntity uses different format where `-` is expected.


Does that mean ...

When opening the GUI for a loader (loader1x1 in my case) entity, the GUI shows the "Use Filters" checkbox and "Whitelist / Blacklist" switch at the bottom.

When changing the settings for the entity while the GUI is open by doing entity.loader_filter_mode = 'blacklist' or entity.loader_filter_mode ...

I received an on_undo_applied event with a single UndoRedo action, a "copy-entity-settings'. This is supposed to contain a BlueprintEntity which in turn contains a SpoilPriority value in spoil_priority. This is supposed to have 'none', 'fresh_first' or 'spoiled_first''.

However, I received 'spoiled ...

If you need to move data between prototype and runtime stage, consider using ModData (https://lua-api.factorio.com/latest/prototypes/ModData.html). If you are just managing data during the prototype stage, the performance does not really matter, concatenating with e.g. ':' or '|' and leaving the ...

After a bit more experimentation, it seems that the Blueprint Sandboxes mod is doing upgrades wrong. When calling entity.apply_upgrade() instead of create_entity with fast_replace, the engine sends out all events correctly (script_raised_destroy, then script_raised_built).

I have a mod (https://mods.factorio.com/mod/miniloader-redux) where each entity relies on creation/deletion events to maintain internal state. This works fine in the regular game.

I register on_built_entity, on_robot_built_entity, on_space_platform_built_entity, script_raised_built, script_raised ...

What are you trying to hash? With entity unit numbers being unique and tables taking string keys, I rarely found a reason to hash anything. Curious what you are trying to do.

Thanks for the report however that is fully intended. They along with electric poles have no distance limit on them since version 0.16 released in 2017.


Hm,

I half-expected something like this. Lamps do have a distance limit. Power-switches sit at a weird intersection; they are only useful for ...

Most (All?) GUIs have a maximum limit from which a player can open their GUI. The outline turns red if the GUI can not be opened:

Screenshot 2026-04-19 at 18.37.24.png
Screenshot 2026-04-19 at 18.37.32.png

Except the power switch. I tried zooming out on a big screen and even at max zoom, I can ...

Do you have a save? I can take a look but I would need a save to look at.

Sure, but windows only and seems mostly vibe-coded with antigravity.

Get a platform independent version?

Osmo wrote: Thu Mar 19, 2026 9:10 pm You can also assign a custom status to the entity, when it is selected/opened by a player

Agreed. However, for a custom status (e.g. low power/no power), I would need to know that this condition exists right now and there is not a good way to find out.

Thanks for the explanation.