Vibe-coded, use at your own risk. This mod was written almost entirely by an AI coding assistant under the
author's direction. It passes a suite of automated headless tests and has seen a little hands-on play, but it has
not been battle-tested, and multiplayer has barely been tried. It may have bugs, including ones that crash the
game or lose the contents of boxes. Back up your saves before adding it, and don't rely on it in a save you
care about. It is provided as is, without warranty of any kind (see the MIT license). Bug reports are welcome,
but there is no promise of support or fixes.

Circuit Box

A 2x2 block that holds a whole combinator circuit inside. Walk into the box, build the circuit in its own private
room, walk out, and use the box like a single combinator. Boxes that share a tag share one circuit, so you can build
a design once and place it many times.

How to use

1. Research Circuit network and craft a Circuit box (10 iron plate, 10 copper cable, 10 electronic circuit).
2. Place it and power it with a copper wire: it connects to a nearby pole automatically, like a pole does.
   The box itself powers nothing around it.
3. Wire up the ports. Facing north, the two inputs (blue) are on the south edge and the two outputs (red)
   are on the north edge. Each port takes a red and a green wire, giving 4 channels in and 4 channels out.
   Hover near the edge of the box to select a port.
4. Open the box and press Enter. Inside is a 32x32 room with the four ports already in place (Input 1/2,
   Output 1/2). Build your circuit from combinators, lamps, displays, speakers, power switches and poles.
5. Press Exit or Ctrl+Shift+E to leave.

Tags

• Type a tag in the box window and press Link. A new tag is created from this box's circuit; if the tag already
  exists, this box's circuit is replaced by the tag's.
• When you leave a linked box (or press Apply), its circuit is copied to every box with the same tag.
• Detach keeps the current circuit and stops syncing that one box.

Cost and refunds

A box costs its own item plus everything built inside it. Until it is paid for, the box is inactive (the ports are not
connected inside). Missing items are taken from the box's own inventory, then from your inventory, and the rest is
requested from construction robots. When a tag's circuit grows, every linked box requests the difference. Mining a
box refunds everything that was paid for it.

Blueprints

Blueprints and copy-paste carry the box's tag, its interior and the wires attached to it outside. If you paste a
blueprint into a save that doesn't have the tag yet, the tag is created from the blueprint.

Performance

The mod does no work every tick. Signals between the outside and the inside pass through the engine's own (hidden)
circuit wires, and power through a hidden copper wire, so a box costs about the same as the combinators inside it.
Script work happens only when boxes are built, mined, rotated, linked or edited.

Known limitations

• You can't enter a box from remote view, including from a space platform hub.
• A box ghost has no ports, so wires can't be attached to it; wires from blueprints are restored when it is built.
• Lamps inside never visibly light up (the interior is always day).
• Items dropped on the floor inside a box are lost if the box is removed.
• Every Exit or Apply re-syncs the whole tag, even if nothing changed.
• Removing the mod deletes every box and everything inside it.

Compatibility

Factorio 2.1. Works with or without Space Age. Multiplayer is supported by design (deterministic, no per-player
state outside events) but has had very little testing.