Announcements

This Update Comes with Some Conditions

This update brings Mother OS 1.3.0, Mother Core 1.2.0, Mother GUI 0.3.0, and Mother Autopilot System (MAPS) 0.3.0. Your constructs can now make decisions. Conditional logic lets any script react to the state of your blocks ("Batteries" low, grid altitude < 100) with when rules and if steps, and every script on the construct shares the same vocabulary. Update all of your scripts at the same time so they run the same version of Mother Core. Mother Core has also grown a bit, so for developers, you may need to prune a bit. Have no fear though, I have pruned Core considerably and the build tools go well beyond what standard MDK2 minification can do.

Release Highlights

  • Conditional logic adds polled when rules, inline if / elseif / else / end steps, text compare, and a [predicates] section for defining your own predicates.
  • Shared vocabulary lets a script use conditions that only another script defines. Mother GUI can test MAPS's inspace, and MAPS can test Mother OS's low, with nothing extra to configure.
  • Mother OS 1.3.0 registers block properties and predicates for batteries, tanks, jump drives, doors, landing gear, pistons, rotors, sensors, cockpits, air vents and thrusters. It also adds a --backup option to battery/charge and $VARIABLES in autolcd views.
  • MAPS 0.3 adds speed, moving, gravity, altitude, inspace and ingravity.
  • Mother GUI 0.3 refreshes displays more reliably on multiplayer servers.
  • Mother Core 1.2 new block command registration syntax to make wiring up commands easier for developers (and also save a ton of characters).

Breaking change: connector commands

connector/lock, connector/unlock and connector/toggle are no longer part of Mother Core. Mother OS still provides them, but Mother GUI and MAPS do not. Developers building on Mother Core should register these commands from their own module.

Conditional Logic

A condition is a target followed by a predicate, or by a property, an operator and a value. Use it in a when rule to run a routine when the condition changes, or in an if step to branch inside any routine.

Mother > Custom Data
; Change these values to match your block and group names.
[variables]
SCREEN="Cockpit:1"
BATTERIES=Batteries
CONNECTOR="Main Connector"

; When our batteries are low, we print to a cockpit screen.
[rules]
LowPower=
| when $BATTERIES low;
|   screen/print $SCREEN "Power is low";
| else;
|   screen/print $SCREEN "Power OK";

; Run docking procedure if connector ready to connect, 
; or notify the user.
[commands]
Dock=
| if $CONNECTOR connectable;
|   connector/lock $CONNECTOR;
| else;
|   view/notify $SCREEN "Cannot lock. No connector detected." --level=error;
| end;

$NAME is replaced with the value from [variables], so you only edit your block names in one place. The examples below use the same pattern.

Indent the steps under each when, if, elseif and else to make the nesting easy to read. Spaces after the | are ignored. Every if needs its own end;, so put else; and end; in the same column as the if they belong to.

Predicates are the names you can use after a target. Each script defines the predicates for the blocks it owns, and shares them with every other script on the construct. Select a tab to see what is available in each script. You can add your own, or change a built-in one, in the [predicates] section of the programmable block's Custom Data.

Mother Core

Available in every script, including Mother GUI.

BlockPredicatesPropertiesState words
Any functional blockon, offenabled
Any blockworking, brokenworking
Connectorconnected, connectable, disconnectedstatusunconnected, connectable, connected

Common Recipes

Rules go in the [rules] section of the programmable block's Custom Data. Commands and menu entries can use if directly. Rules run when a condition changes, so a rule only fires when its condition goes from false to true, and its optional else; branch fires when it goes back to false. Replace the quoted block and group names with your own.

Airlock

Two commands cycle the airlock, and each step checks that the previous one worked before moving on. The inner door must be closed before the vent depressurizes, and the vent must be depressurized before the outer door opens. Two rules act as an interlock, so both doors can never be open at the same time, even if a player opens one by hand.

Mother OS > Custom Data
[variables]
SCREEN="Cockpit:1"
DOOR_INNER="Airlock Inner"
DOOR_OUTER="Airlock Outer"
VENT="Airlock Vent"

[commands]
AirlockExit=
| door/close $DOOR_INNER;
| wait 2;
| if $DOOR_INNER closed;
|   vent/depressurize $VENT;
|   wait 5;
|   if $VENT depressurized;
|     door/open $DOOR_OUTER;
|   else;
|     view/notify $SCREEN "Airlock is still depressurizing." --level=warning;
|   end;
| else;
|   view/notify $SCREEN "Inner door is blocked." --level=error;
| end;

AirlockEnter=
| door/close $DOOR_OUTER;
| wait 2;
| if $DOOR_OUTER closed;
|   vent/pressurize $VENT;
|   wait 5;
|   if $VENT pressurized;
|     door/open $DOOR_INNER;
|   else;
|     view/notify $SCREEN "Airlock is still pressurizing." --level=warning;
|   end;
| else;
|   view/notify $SCREEN "Outer door is blocked." --level=error;
| end;

[rules]
InterlockOuter=
| when $DOOR_OUTER open;
|   door/close $DOOR_INNER;

InterlockInner=
| when $DOOR_INNER open;
|   door/close $DOOR_OUTER;

Explore Mother OS: Conditional Logic | Ready-Made Recipes | Your Own Predicates | Upgrade Guide

Explore Mother GUI: Conditional Menu Entries | Upgrade Guide

Explore Mother Autopilot System (MAPS): Ship Conditions | Upgrade Guide

Explore Mother Core: Upgrade Guide (Breaking Changes) | Conditions | Registering Block Commands | Managing Script Size

October 2026 Update

This update brings Mother OS 1.2, Mother Core 1.1.4, Mother GUI 0.2, and Mother Autopilot System (MAPS) 0.2. It adds Automatic LCDs 2 support, in-menu notifications, and lets scripts share screens with each other. There are no breaking changes, but update all of your scripts at the same time so they run the same version of Mother Core.

Release Highlights

  • Mother OS 1.2 adds the autolcd/print and autolcd/clear commands, and expands screen/print with bgcolor, alignment and padding options. Sorters gain sorter/mode, sorter/add, sorter/remove and sorter/clear for managing item filters.
  • Mother Core 1.1.4 adds the halt command, shared views between scripts, quoted option values, and fixes for merge and unmerge handling.
  • Mother GUI 0.2 adds the view/notify command, custom menu titles, scroll indicators, and a simpler < Back entry on every menu.
  • MAPS 0.2 shares MapView with Mother GUI so one screen can switch between a menu and the map.

Check out the Nova Blade Mk1 (Steam Workshop - designed as a demonstration aircraft for the synergy of Mother OS, Mother GUI and Mother Autopilot System, all built using Mother Core.

Mother OS 1.2

Players can now show Automatic LCDs 2 views on any screen with a single command. Define named views in the [autolcd] section of the programmable block, then print them to a screen. Use autolcd/clear to remove config from a screen.

Mother > Custom Data
[commands]
ShowPowerView=autolcd/print "Cockpit:1" PowerView

[autolcd]
PowerView=
| Power {T:*}
| Working {TG:Batteries}

Automatic LCDs 2 Support

Conveyor sorters now support filtering. Switch a sorter between whitelist and blacklist with sorter/mode, and manage its filter list with sorter/add, sorter/remove and sorter/clear. Items are written as Type/Subtype (such as Ore/Iron), or as a type alone (such as Ore) to match every item of that type. sorter/add accepts --fresh and --mode so a sorter can be fully reconfigured in a single command.

Terminal
sorter/add "Cargo Sorter" Ore/Stone Ore/Ice --fresh --mode=blacklist;

Explore Mother OS: AutoLCD Module | Sorter Module | Upgrade Guide

Mother GUI 0.2

Mother GUI can now give feedback to the player and is a bit easier to use. Use view/notify to show a transient message in the footer of a view, and --title with view/go to replace the header of a menu. Menus show scroll indicators when they overflow, use a larger and more readable font, and every menu with history shows a < Back option. Rather than nesting multiple menu layers, this simplifies a modular menu structure with navigation history.

Terminal
view/notify "Cockpit:1" "Docking complete" --level=success --duration=5;
view/go "Cockpit:1" MapMenu --title="Map Menu Title";

Automatic LCDs 2 Support

Explore Mother GUI: Notifications | MenuView

Mother Autopilot System 0.2

MapView can now be opened from Mother GUI. A cockpit screen can show a menu, switch to the map with view/go, and return with view/back.

Explore MAPS: Map Module | Upgrade Guide

Mother Core 1.1.4

Scripts now share views in the same way they share commands, so a script can draw on a screen owned by another script. Developers also get the halt command, the ConstructRefreshedEvent, a preserveState option for block state monitoring, and options that accept double-quoted values.

Explore Mother Core: Upgrade Guide | Intergrid Message Service | Command Bus

Version 1.1 Update - 12 May 2026

The upcoming Mother ecosystem release brings together Mother OS 1.1, Mother Core 1.1, Mother Autopilot System 0.1, Mother GUI 0.1, and the expanded Mother CLI 1.1 command experience. This release separates flight systems into a dedicated companion script, broadens the in-game command model, modernizes display configuration, and opens up more focused entry points for both players and developers.

Release Highlights

  • Mother OS 1.1 adds variables, runtime command parameters, parallel routines, wheel suspension commands, cumulative --share movement, block renaming, hex colors, and the new onBoot hook.
  • Mother Core 1.1 moves display targeting into Custom Data, consolidates logging, adds command priority, and improves mechanical and merge block awareness.
  • Mother Autopilot System (MAPS) 0.1 launches as a standalone companion for flight planning, flight control, docking, attitude control, and Map/Almanac displays.
  • Mother GUI 0.1 launches as a new display-focused script for interactive menus and live mechanical views.

Upgrading from Mother 1.0?

If you use flight plans, docking, gyro/face, or fcs/* commands, install MAPS on a second programmable block alongside Mother OS. The nav/set-flight-plan command has been renamed to fp/set, and Map/Almanac displays are now rendered by MAPS.

Mother OS 1.1

Mother OS 1.1 expands day-to-day ship automation without changing the familiar programmable-block workflow. Players can define reusable $VARIABLES, build commands with {{runtime parameters}}, run routines in parallel, and control more block types directly. Wheel suspension controls, shared piston/rotor/hinge movement with --share, block/rename, grid renaming, and hex color support all land in this release.

Mother > Custom Data
[variables]
PLAYER=Dave

[commands]
Greeting=screen/print BedroomDisplay "Good morning, $PLAYER"
OpenAirlock=
| wait 5;
| { door/open AirlockDoor1 }
| { door/open AirlockDoor2 }

Explore Mother OS: Overview | Installation | Upgrade Guide | Examples

Mother Core 1.1

Mother Core 1.1 is the shared foundation under Mother OS, MAPS, and Mother GUI. Displays are now configured in Custom Data instead of block names, the old Debug and Log split is replaced by the unified Log module, and map and almanac rendering move out into MAPS. Developers also get new command priority behavior, the onBoot hook, clearer instance naming (self, construct, remote), and better catalogue updates when merge blocks and mechanical connections change.

Explore Mother Core: Overview | Installation | Upgrade Guide | Core Modules

Mother Autopilot System (MAPS) 0.1

MAPS is the new standalone autopilot companion for Mother-powered constructs. The initial release packages Flight Control, Flight Planning, Docking, Attitude, and Map functionality into a dedicated script that runs beside Mother OS. Install it on a second programmable block and Mother Core will automatically share commands across both scripts during boot, so players do not need to remember which block owns which feature.

For players migrating existing automations, the key command change is simple: nav/set-flight-plan is now fp/set.

Explore MAPS: Overview | Installation | Upgrade Guide | Flight Planning | Docking

Mother GUI 0.1

Mother GUI is a brand new script focused on shipboard interfaces. It turns LCDs, cockpits, programmable blocks, and other text surfaces into navigable menus and live mechanical status views. Configure screens with [surfaces], drive navigation with view/* commands, and reuse the same menus across multiple displays with view/go self ... for a clean, scalable UI layer that fits naturally beside Mother OS.

Explore Mother GUI: Overview | Installation | MenuView | Commands | Views

Where To Start

If you want to...Start here
Automate a ship or station with commands and routinesMother OS
Add flight plans, attitude control, or dockingMAPS
Build navigable displays and mechanical dashboardsMother GUI
Create your own programmable block scriptsMother Core
Learn the command syntax or scaffold project filesMother CLI
Last Updated:
Contributors: Luke Morrison, lukejamesmorrison