Automatic Underground Pipe Connectors for 2.1


Automatically place a pipe when two undergrounds are placed at a corner or one space apart

Utilities
4 days ago
2.1
33

Changelog

Version: 2.1.2
Date: 2026-07-25
  Changes:
    - underground dragging will no longer delete pipe ghosts (those created at inactive fluid ports will still be deleted)
Version: 2.1.1
Date: 2026-07-12
  Bugfixes:
    - Respect fluidbox connection categories so a connecting pipe is only auto-placed when it can
      actually connect; fixes spurious placements with tiered-fluid mods (e.g. Pyanodons braided
      pipes via Advanced Fluid Handling) where mismatched tiers cannot join
Version: 2.1.0
Date: 2026-07-12
  Changes:
    - Updated for Factorio 2.1
    - Consider both real and ghost entities when looking for fluid connections
    - Removed obsolete fluid-wagon connection guard (worked around a Factorio 1.1 issue no longer present in 2.x)
  Compatibility:
    - Migrated neighbor fluidbox checks to the 2.1 prototype API
    - Declared base >= 2.1 dependency
Version: 2.0.11
Date: 2025-06-11
  Changes:
    - Revert to 2.0.3 entity creation strategy. Break Aquilo tile placement again.
Version: 2.0.10
Date: 2025-06-11
  Bugfixes:
    - Underground was re-placed as ghost when pipe missing from inventory
    - Error on placement of non-unit entity
Version: 2.0.9
Date: 2025-06-06
  Bugfixes:
    - Underground dragging immediately placed unnecessary underground after pipe placement
    - Ghost undergrounds connected to ghost buildings in the same blueprint
Version: 2.0.8
Date: 2025-05-31
  Bugfixes:
    - Crash error caused by previous fix to hand icon, now broken again temporarily
Version: 2.0.7
Date: 2025-05-31
  Bugfixes:
    - Error due to new underground entity invalidated mid-tick
Version: 2.0.6
Date: 2025-05-30
  Changes:
    - No connections between any undergrounds created in the same tick, not just for blueprints
  Bugfixes:
    - Reserved inventory slot (hand icon) was lost for blueprint/pipe when mod triggered
    - Pipes no longer fast replace valves or other pipe-like entities
    - Pipes with weird connection offsets now connect correctly
    - First underground of multiple created in a tick no longer ignored
Version: 2.0.5
Date: 2025-05-29
  Bugfixes:
    - Error due to new underground entity invalidated mid-tick
Version: 2.0.4
Date: 2025-05-28
  Features:
    - Remote interface for reading, updating, replacing the underground to pipe lookup table
  Changes:
    - Refactor API usage to use build_from_cursor and support ice-platform
  Bugfixes:
    - Temporary blueprints dropped to inventory
    - Undergrounds in blueprints creating pipes prematurely
    - Ghost pipes counting as automatic connection targets
Version: 2.0.3
Date: 2025-05-24
  Bugfixes:
    - Fixed undo/redo not working
Version: 2.0.2
Date: 2024-11-02
  Bugfixes:
    - Another crash on missing player inventory
Version: 2.0.1
Date: 2024-11-01
  Features:
    - Place tile ghost to support automatic connector over water, space, lava, etc
  Bugfixes:
    - Crash on missing player inventory
Version: 2.0.0
Date: 2024-10-23
  Features:
    - Recognizes dynamic fluid inputs, such as on Assemblers
  Changes:
    - Support for Factorio 2.0
Version: 1.2.0
Date: 2024-09-14
  Features:
    - Support non-pipe ghosts with fluidboxes as connectable neighbors
  Changes:
    - Replace custom vector lookup with util.direction_vectors
    - Add LuaLS annotations to source for all types and functions
    - Improve source comments
    - Improve source naming
Version: 1.1.3
Date: 2023-12-09
  Bugfixes:
    - Crash with mods that add underground pipe recipes with fluid ingredients
Version: 1.1.2
Date: 2023-12-09
  Bugfixes:
    - Crash with mods that add underground pipe recipes with byproducts
Version: 1.1.1
Date: 2023-11-02
  Bugfixes:
    - Crash when checking invalid fluid-turret fluidbox
Version: 1.1.0
Date: 2023-06-18
  Features:
    - Replace ghost pipes
    - Place ghost pipes when placing ghost underground pipes
    - Place ghosts/pipes when placing near non-pipe entities with fluid connections
Version: 1.0.4
Date: 2021-12-28
  Changes:
    - Version bump for Factorio 1.1
Version: 1.0.3
Date: 2021-12-28
  Bugfixes:
    - Avoid errors on unrecognized pipes
    - Avoid replacing fast-replace-able entities like other pipes
Version: 1.0.2
Date: 2020-09-07
  Features:
    - Prevent mixing fluids
Version: 1.0.1
Date: 2020-09-06
  Features:
    - Automatically place a pipe when two undergrounds are placed at a corner or one space apart
  Other:
    - First version!