Jigsaw junctions and studio tools

- Rotatable jigsaw candidates try their rotations in random order
- Candidate connectors are tried by priority within each rotation
- Planar candidates must agree with every occupied neighbor socket
- Planar assembly falls back to source-only matching before it fails
- Connectors whose branch placed nothing stay open
- Spatial default kit covers all 24 Y-rotation topologies
- Planar start pool includes Blank at weight 1
- Vanilla spatial projects omit Iris themes and placement caps
- Vanilla spatial projects use max depth 4
- 1.21.1 export derives the vertical distance from the structure
- Workcell floors map the active variant's connectors
- Floor froglights mark up, down and up-down connectors
- Connector Tool places, moves, re-orients and removes spatial connectors
- Connector Tool re-seats planar face-center sockets
- Main menu pages workcells five at a time
- Spatial variants can be deleted while another variant remains
- Tool sticks act on the variant they were made for
- Destructive tool confirmation needs two separate clicks
- Pistons cannot extend into protected cells
- Autosave capture failures back off and notify the owner
- Autosave plays the save bell
- Hidden-connector air final states are stored as air
- Reset Connector Blocks clears unsaved markers
- Folia logout releases reset and resize reservations
- Spatial workcell rename relabels its variant
- Workcell teleports land inside the focused workcell
- Replacement layouts keep rendering and hydration working
- Container preview probes stay out of chat
- Non-owners can run commands that are not recognized as mutating
- Spatial resize or rotation past the workcell volume limit is refused
- Tests cover default kit assembly, connector placement, floor glyphs and menu paging

adapters/bukkit/plugin/src/main/java/art/arcane/iris/command/CommandJigsaw.java

@@ -23,6 +23,7 @@ import art.arcane.iris.structure.authoring.StructureKey;
 import art.arcane.iris.structure.authoring.StructureWriteResult;
 import art.arcane.iris.structure.export.VanillaJigsawExportFormat;
 import art.arcane.iris.structure.export.VanillaJigsawExportRequest;
+import art.arcane.iris.structure.export.VanillaJigsawExportSettings;
 import art.arcane.iris.structure.export.VanillaJigsawExportSource;
 import art.arcane.iris.structure.graph.PlanarJigsawWorkcellResolver;
 import art.arcane.iris.generation.terrain.IrisDimension;
@@ -437,13 +438,14 @@ public class CommandJigsaw implements DirectorExecutor {
         }
         VanillaJigsawExportRequest request;
         try {
-            request = VanillaJigsawExportRequest.builder(
+            VanillaJigsawExportSource source = VanillaJigsawExportSource.forData(
-                            VanillaJigsawExportSource.forData(
+                    context.request().source(), context.request().structureKey());
-                                    context.request().source(), context.request().structureKey()), destination)
+            request = VanillaJigsawExportRequest.builder(source, destination)
                     .namespace(namespace)
                     .resourcePath(context.request().structureKey())
                     .format(exportFormat)
                     .replaceExisting(replace)
+                    .settings(VanillaJigsawExportSettings.runtimeDefaults(source.loadStructure()))
                     .build();
         } catch (IllegalArgumentException exception) {
             sendError(exception.getMessage());

core/src/main/java/art/arcane/iris/structure/export/VanillaJigsawExportSettings.java

@@ -1,5 +1,8 @@
 package art.arcane.iris.structure.export;
 
+import art.arcane.iris.pack.datapack.DataVersion;
+import art.arcane.iris.structure.placement.IrisStructure;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
@@ -41,6 +44,13 @@ public final class VanillaJigsawExportSettings {
         return builder().build();
     }
 
+    public static VanillaJigsawExportSettings runtimeDefaults(IrisStructure structure) {
+        if (structure == null || DataVersion.getRuntime() != DataVersion.V1_21_1) {
+            return defaults();
+        }
+        return builder().maxDistanceVertical(structure.getMaxSizeChunks() * 16).build();
+    }
+
     public List<String> biomes() {
         return biomes;
     }

core/src/main/java/art/arcane/iris/structure/jigsaw/IrisJigsawConnector.java

@@ -89,7 +89,7 @@ public class IrisJigsawConnector {
     @Description("Block state placed where this jigsaw marker was authored after assembly. Used when exporting or capturing Mojang-style jigsaw templates.")
     private String finalState = "minecraft:air";
 
-    @Description("Signed priority for selecting this connector within its piece. Higher values are processed before lower values; equal priorities preserve authored order.")
+    @Description("Signed priority for selecting this connector within its piece. Higher values are processed before lower values; equal priorities preserve authored order. A rotatable candidate piece applies this order within each of its cardinal rotations, which it tries in random order.")
     private int selectionPriority = 0;
 
     @Description("Signed priority assigned to a child piece attached through this connector. Higher-priority child pieces expand first; equal priorities preserve attachment order.")

core/src/main/java/art/arcane/iris/structure/jigsaw/IrisJigsawWorkcellArchetype.java

@@ -4,7 +4,7 @@ import art.arcane.volmlib.util.documentation.Description;
 
 @Description("The orientation-independent connector shape represented by a planar jigsaw workcell.")
 public enum IrisJigsawWorkcellArchetype {
-    @Description("Pieces with no horizontal connectors: sealed filler cells that terminate nothing and are excluded from the default piece pool.")
+    @Description("Pieces with no horizontal connectors. Nothing can attach to them, so they generate only as standalone start pieces; new projects list the default Blank in the start pool and exclude it from the piece pool.")
     BLANK(0),
 
     @Description("One-connector dead-end pieces; the Studio bay seeds a single north connector and new projects mark these as terminal caps.")

core/src/main/java/art/arcane/iris/structure/placement/StructureAssembler.java

@@ -218,7 +218,7 @@ public final class StructureAssembler {
                             + "' references missing connector pool '" + connector.pool + "'");
                 }
 
-                AttachmentResult attachment = attachOne(
+                AttachmentResult attachment = attach(
                         pending,
                         placed,
                         placementCounts,
@@ -229,7 +229,9 @@ public final class StructureAssembler {
                         depth,
                         selectedTheme,
                         rng);
-                consume(consumedConnectors, connector.sourcePiece(), connector.sourceConnector());
+                if (attachment.state() != AttachmentState.TERMINATED) {
+                    consume(consumedConnectors, connector.sourcePiece(), connector.sourceConnector());
+                }
                 if (attachment.state() == AttachmentState.FAILED) {
                     return StructureAssemblyResult.failed(
                             StructureAssemblyStatus.FAILED_UNCAPPED,
@@ -250,6 +252,49 @@ public final class StructureAssembler {
         return StructureAssemblyResult.complete(placed, selectedTheme);
     }
 
+    private AttachmentResult attach(
+            Deque<PieceExpansion> pending,
+            KList<PlacedStructurePiece> placed,
+            Map<String, Integer> placementCounts,
+            Map<PlacedStructurePiece, Set<IrisJigsawConnector>> consumedConnectors,
+            Map<PlacedStructurePiece, Map<IrisJigsawConnector, OpenConnector>> openConnectors,
+            IrisJigsawPool pool,
+            OpenConnector connector,
+            int depth,
+            String selectedTheme,
+            RNG rng
+    ) {
+        boolean planarNeighborClosures = structure.resolvedMode() == IrisJigsawMode.PLANAR_JIGSAW
+                && !structure.isRequireCaps();
+        AttachmentResult agreed = attachOne(
+                pending,
+                placed,
+                placementCounts,
+                consumedConnectors,
+                openConnectors,
+                pool,
+                connector,
+                depth,
+                selectedTheme,
+                structure.isRequireCaps() || planarNeighborClosures,
+                rng);
+        if (agreed.state() != AttachmentState.FAILED || !planarNeighborClosures) {
+            return agreed;
+        }
+        return attachOne(
+                pending,
+                placed,
+                placementCounts,
+                consumedConnectors,
+                openConnectors,
+                pool,
+                connector,
+                depth,
+                selectedTheme,
+                false,
+                rng);
+    }
+
     private AttachmentResult attachOne(
             Deque<PieceExpansion> pending,
             KList<PlacedStructurePiece> placed,
@@ -260,6 +305,7 @@ public final class StructureAssembler {
             OpenConnector connector,
             int depth,
             String selectedTheme,
+            boolean neighborClosures,
             RNG rng
     ) {
         if (pool.getPieces() == null) {
@@ -281,6 +327,7 @@ public final class StructureAssembler {
                     selectedTheme,
                     false,
                     !fallbackRequired,
+                    neighborClosures,
                     rng);
             if (primary != AttachmentState.NO_MATCH) {
                 return AttachmentResult.success(primary);
@@ -322,6 +369,7 @@ public final class StructureAssembler {
                 selectedTheme,
                 fallbackRequired,
                 !fallbackRequired,
+                neighborClosures,
                 rng);
         if (fallbackState != AttachmentState.NO_MATCH) {
             return AttachmentResult.success(fallbackState);
@@ -352,9 +400,14 @@ public final class StructureAssembler {
             String selectedTheme,
             boolean terminalOnly,
             boolean allowEmpty,
+            boolean neighborClosures,
             RNG rng
     ) {
         int ruleDepth = Math.min(connector.pieceDepth, structure.getMaxDepth());
+        if (connector.targetName == null) {
+            throw assemblyFailure("open connector from pool '" + connector.pool + "' has no target name");
+        }
+        IrisDirection needed = connector.facing.reverse();
         for (IrisJigsawPieceEntry entry : weightedOrder(
                 pool,
                 selectedTheme,
@@ -391,21 +444,16 @@ public final class StructureAssembler {
                 requireConnector(pieceConnector, pieceName);
             }
             List<IrisJigsawConnector> candidateConnectors = orderedConnectors(piece.getConnectors(), null);
-            for (IrisJigsawConnector cb : candidateConnectors) {
+            int[] rotations = piece.isRotatable() ? shuffledRotations(rng) : NO_ROTATION;
-                if (connector.targetName == null) {
+            for (int yDeg : rotations) {
-                    throw assemblyFailure("open connector from pool '" + connector.pool + "' has no target name");
+                IrisObjectRotation rot = IrisObjectRotation.of(0, yDeg, 0);
-                }
+                for (IrisJigsawConnector cb : candidateConnectors) {
-                if (!Objects.equals(connector.channel, cb.getChannel())) {
+                    if (!Objects.equals(connector.channel, cb.getChannel())) {
-                    continue;
+                        continue;
-                }
+                    }
-                if (!cb.getName().equals(connector.targetName)) {
+                    if (!cb.getName().equals(connector.targetName)) {
-                    continue;
+                        continue;
-                }
+                    }
-
-                IrisDirection needed = connector.facing.reverse();
-                int[] rotations = piece.isRotatable() ? rotationCandidates(connector.joint, rng) : NO_ROTATION;
-                for (int yDeg : rotations) {
-                    IrisObjectRotation rot = IrisObjectRotation.of(0, yDeg, 0);
                     IrisDirection rotatedFace = rot.rotate(cb.getDirection());
                     if (rotatedFace != needed) {
                         continue;
@@ -431,7 +479,8 @@ public final class StructureAssembler {
                             consumedConnectors,
                             connector,
                             candidate,
-                            cb);
+                            cb,
+                            neighborClosures);
                     if (closures == null) {
                         continue;
                     }
@@ -504,9 +553,10 @@ public final class StructureAssembler {
             Map<PlacedStructurePiece, Set<IrisJigsawConnector>> consumedConnectors,
             OpenConnector attachmentSource,
             PlacedStructurePiece candidatePiece,
-            IrisJigsawConnector attachmentConnector
+            IrisJigsawConnector attachmentConnector,
+            boolean neighborClosures
     ) {
-        if (!structure.isRequireCaps()) {
+        if (!neighborClosures) {
             return List.of();
         }
         List<ConnectorClosure> closures = new ArrayList<>();
@@ -1025,10 +1075,7 @@ public final class StructureAssembler {
         return false;
     }
 
-    private int[] rotationCandidates(JigsawJoint joint, RNG rng) {
+    private int[] shuffledRotations(RNG rng) {
-        if (joint == JigsawJoint.ALIGNED) {
-            return Y_DEGREES;
-        }
         int[] shuffled = {0, 90, 180, 270};
         for (int i = shuffled.length - 1; i > 0; i--) {
             int j = rng.i(i + 1);

core/src/main/java/art/arcane/iris/studio/generation/JigsawStudioGenerator.java

@@ -1,12 +1,11 @@
 package art.arcane.iris.studio.generation;
 
-import art.arcane.iris.studio.jigsaw.JigsawPlanarDirection;
-import art.arcane.iris.studio.jigsaw.JigsawPlanarTopology;
 import art.arcane.iris.studio.jigsaw.JigsawStudioActivation;
 import art.arcane.iris.studio.jigsaw.JigsawStudioBay;
 import art.arcane.iris.studio.jigsaw.JigsawStudioBounds;
 import art.arcane.iris.studio.jigsaw.JigsawStudioCellDimensions;
 import art.arcane.iris.studio.jigsaw.JigsawStudioControlPosition;
+import art.arcane.iris.studio.jigsaw.JigsawStudioFloorGlyph;
 import art.arcane.iris.studio.jigsaw.JigsawStudioLayout;
 import art.arcane.iris.studio.jigsaw.JigsawStudioSession;
 import art.arcane.iris.studio.jigsaw.JigsawStudioVariant;
@@ -51,9 +50,7 @@ public final class JigsawStudioGenerator extends EnginedStudioGenerator {
     private final NativeBlockState lightFloor;
     private final NativeBlockState darkFloor;
     private final NativeBlockState frame;
-    private final NativeBlockState topologyBase;
+    private final FloorPalette floorPalette;
-    private final NativeBlockState topologyPath;
-    private final NativeBlockState connectorCap;
     private final NativeBlockState invalidMarker;
     private final NativeBlockState controlChest;
     private final FinalStateRenderer finalStateRenderer;
@@ -79,9 +76,13 @@ public final class JigsawStudioGenerator extends EnginedStudioGenerator {
                 B.getState("minecraft:smooth_stone"),
                 B.getState("minecraft:polished_deepslate"),
                 B.getState("minecraft:white_concrete"),
-                B.getState("minecraft:light_gray_wool"),
+                new FloorPalette(
-                B.getState("minecraft:red_wool"),
+                        B.getState("minecraft:light_gray_wool"),
-                B.getState("minecraft:sea_lantern"),
+                        B.getState("minecraft:red_wool"),
+                        B.getState("minecraft:sea_lantern"),
+                        B.getState("minecraft:verdant_froglight"),
+                        B.getState("minecraft:ochre_froglight"),
+                        B.getState("minecraft:pearlescent_froglight")),
                 B.getState("minecraft:red_stained_glass"),
                 B.getState("minecraft:chest[facing=south,type=single,waterlogged=false]"),
                 JigsawStudioGenerator::rotatedFinalState
@@ -95,9 +96,7 @@ public final class JigsawStudioGenerator extends EnginedStudioGenerator {
             NativeBlockState lightFloor,
             NativeBlockState darkFloor,
             NativeBlockState frame,
-            NativeBlockState topologyBase,
+            FloorPalette floorPalette,
-            NativeBlockState topologyPath,
-            NativeBlockState connectorCap,
             NativeBlockState invalidMarker,
             NativeBlockState controlChest,
             FinalStateRenderer finalStateRenderer
@@ -108,9 +107,7 @@ public final class JigsawStudioGenerator extends EnginedStudioGenerator {
         this.lightFloor = Objects.requireNonNull(lightFloor, "Jigsaw Studio light floor block");
         this.darkFloor = Objects.requireNonNull(darkFloor, "Jigsaw Studio dark floor block");
         this.frame = Objects.requireNonNull(frame, "Jigsaw Studio frame block");
-        this.topologyBase = Objects.requireNonNull(topologyBase, "Jigsaw Studio topology base block");
+        this.floorPalette = Objects.requireNonNull(floorPalette, "Jigsaw Studio floor palette");
-        this.topologyPath = Objects.requireNonNull(topologyPath, "Jigsaw Studio topology path block");
-        this.connectorCap = Objects.requireNonNull(connectorCap, "Jigsaw Studio connector cap block");
         this.invalidMarker = Objects.requireNonNull(invalidMarker, "Jigsaw Studio invalid marker block");
         this.controlChest = Objects.requireNonNull(controlChest, "Jigsaw Studio control chest block");
         this.finalStateRenderer = Objects.requireNonNull(
@@ -165,6 +162,21 @@ public final class JigsawStudioGenerator extends EnginedStudioGenerator {
         return renderedBays.computeIfAbsent(key, ignored -> buildRenderedBay(activeWorkcell, variant));
     }
 
+    public JigsawStudioFloorGlyph floorGlyph(JigsawStudioBay workcell) {
+        return glyphFor(renderBay(workcell));
+    }
+
+    public NativeBlockState floorState(JigsawStudioFloorGlyph.Cell cell) {
+        return switch (Objects.requireNonNull(cell, "Jigsaw Studio floor glyph cell")) {
+            case BASE -> floorPalette.base();
+            case LINE -> floorPalette.line();
+            case HORIZONTAL_SOCKET -> floorPalette.horizontalSocket();
+            case UP_SOCKET -> floorPalette.upSocket();
+            case DOWN_SOCKET -> floorPalette.downSocket();
+            case UP_AND_DOWN_SOCKET -> floorPalette.upAndDownSocket();
+        };
+    }
+
     public void invalidateRender(String workcellId) {
         if (workcellId != null) {
             renderedBays.keySet().removeIf(key -> key.workcellId().equals(workcellId));
@@ -215,10 +227,8 @@ public final class JigsawStudioGenerator extends EnginedStudioGenerator {
                 continue;
             }
             paintCage(terrainChunk, workcell, chunkWorldX, chunkWorldZ);
-            if (workcell.archetype().isPresent()) {
-                paintTopologyGlyph(terrainChunk, workcell, chunkWorldX, chunkWorldZ);
-            }
             RenderedBay renderedBay = renderBay(workcell);
+            paintFloorGlyph(terrainChunk, workcell, glyphFor(renderedBay), chunkWorldX, chunkWorldZ);
             if (!renderedBay.valid()) {
                 paintInvalidBay(terrainChunk, workcell, chunkWorldX, chunkWorldZ);
                 continue;
@@ -345,85 +355,44 @@ public final class JigsawStudioGenerator extends EnginedStudioGenerator {
         }
     }
 
-    private void paintTopologyGlyph(
+    private void paintFloorGlyph(
             TerrainChunk terrainChunk,
             JigsawStudioBay workcell,
+            JigsawStudioFloorGlyph glyph,
             int chunkWorldX,
             int chunkWorldZ
     ) {
-        JigsawPlanarTopology topology = workcell.topology().orElseThrow();
         JigsawStudioBounds bounds = workcell.bounds();
         int minimumX = Math.max(bounds.originX(), chunkWorldX);
         int maximumX = Math.min(bounds.maxX(), chunkWorldX + 15);
         int minimumZ = Math.max(bounds.originZ(), chunkWorldZ);
         int maximumZ = Math.min(bounds.maxZ(), chunkWorldZ + 15);
-        if (minimumX > maximumX || minimumZ > maximumZ) {
+        int floorY = bounds.originY() - 1;
-            return;
-        }
-        int glyphY = bounds.originY() - 1;
-        int centerX = bounds.dimensions().width() / 2;
-        int centerZ = bounds.dimensions().depth() / 2;
         for (int worldX = minimumX; worldX <= maximumX; worldX++) {
-            int localX = worldX - bounds.originX();
             for (int worldZ = minimumZ; worldZ <= maximumZ; worldZ++) {
-                int localZ = worldZ - bounds.originZ();
+                NativeBlockState state = floorState(glyph.cell(
-                NativeBlockState state = topologyGlyphState(topology, bounds.dimensions(), localX, localZ,
+                        worldX - bounds.originX(),
-                        centerX, centerZ);
+                        worldZ - bounds.originZ()));
-                setWorldBlock(terrainChunk, worldX, glyphY, worldZ, state, chunkWorldX, chunkWorldZ);
+                setWorldBlock(terrainChunk, worldX, floorY, worldZ, state, chunkWorldX, chunkWorldZ);
             }
         }
     }
 
-    private NativeBlockState topologyGlyphState(
+    private static JigsawStudioFloorGlyph glyphFor(RenderedBay renderedBay) {
-            JigsawPlanarTopology topology,
+        if (!renderedBay.valid() || renderedBay.connectors().isEmpty()) {
-            JigsawStudioCellDimensions dimensions,
+            return JigsawStudioFloorGlyph.empty();
-            int localX,
-            int localZ,
-            int centerX,
-            int centerZ
-    ) {
-        if (isConnectorCap(topology, dimensions, localX, localZ, centerX, centerZ)) {
-            return connectorCap;
         }
-        if (isTopologyPath(topology, localX, localZ, centerX, centerZ)) {
+        List<JigsawStudioFloorGlyph.Marker> markers = new ArrayList<>(renderedBay.connectors().size());
-            return topologyPath;
+        for (RenderedConnector connector : renderedBay.connectors()) {
+            markers.add(new JigsawStudioFloorGlyph.Marker(
+                    connector.x(),
+                    connector.z(),
+                    connector.connector().getDirection()));
         }
-        return topologyBase;
+        return JigsawStudioFloorGlyph.of(
-    }
+                renderedBay.dimensions().width(),
-
+                renderedBay.dimensions().depth(),
-    static boolean isConnectorCap(
+                markers);
-            JigsawPlanarTopology topology,
-            JigsawStudioCellDimensions dimensions,
-            int localX,
-            int localZ,
-            int centerX,
-            int centerZ
-    ) {
-        return topology.connects(JigsawPlanarDirection.NORTH) && localX == centerX && localZ == 0
-                || topology.connects(JigsawPlanarDirection.EAST)
-                && localX == dimensions.width() - 1 && localZ == centerZ
-                || topology.connects(JigsawPlanarDirection.SOUTH)
-                && localX == centerX && localZ == dimensions.depth() - 1
-                || topology.connects(JigsawPlanarDirection.WEST) && localX == 0 && localZ == centerZ;
-    }
-
-    static boolean isTopologyPath(
-            JigsawPlanarTopology topology,
-            int localX,
-            int localZ,
-            int centerX,
-            int centerZ
-    ) {
-        if (topology == JigsawPlanarTopology.BLANK) {
-            return false;
-        }
-        boolean vertical = localX == centerX
-                && (topology.connects(JigsawPlanarDirection.NORTH) && localZ <= centerZ
-                || topology.connects(JigsawPlanarDirection.SOUTH) && localZ >= centerZ);
-        boolean horizontal = localZ == centerZ
-                && (topology.connects(JigsawPlanarDirection.WEST) && localX <= centerX
-                || topology.connects(JigsawPlanarDirection.EAST) && localX >= centerX);
-        return vertical || horizontal;
     }
 
     private RenderedBay buildRenderedBay(JigsawStudioBay workcell, JigsawStudioVariant variant) {
@@ -720,7 +689,7 @@ public final class JigsawStudioGenerator extends EnginedStudioGenerator {
 
     private JigsawStudioBay requireWorkcell(JigsawStudioBay workcell) {
         JigsawStudioBay activeWorkcell = Objects.requireNonNull(workcell, "Jigsaw Studio workcell");
-        if (getLayout().get(activeWorkcell.stableId()) != activeWorkcell) {
+        if (!activeWorkcell.equals(getLayout().get(activeWorkcell.stableId()))) {
             throw new IllegalArgumentException("Workcell does not belong to this Jigsaw Studio layout");
         }
         return activeWorkcell;
@@ -884,6 +853,24 @@ public final class JigsawStudioGenerator extends EnginedStudioGenerator {
         }
     }
 
+    public record FloorPalette(
+            NativeBlockState base,
+            NativeBlockState line,
+            NativeBlockState horizontalSocket,
+            NativeBlockState upSocket,
+            NativeBlockState downSocket,
+            NativeBlockState upAndDownSocket
+    ) {
+        public FloorPalette {
+            Objects.requireNonNull(base, "Jigsaw Studio floor base block");
+            Objects.requireNonNull(line, "Jigsaw Studio floor line block");
+            Objects.requireNonNull(horizontalSocket, "Jigsaw Studio horizontal socket block");
+            Objects.requireNonNull(upSocket, "Jigsaw Studio upward socket block");
+            Objects.requireNonNull(downSocket, "Jigsaw Studio downward socket block");
+            Objects.requireNonNull(upAndDownSocket, "Jigsaw Studio vertical socket block");
+        }
+    }
+
     public record RenderedBlock(int x, int y, int z, NativeBlockState state, TileData tileData) {
         public RenderedBlock {
             state = Objects.requireNonNull(state, "Jigsaw Studio rendered block state");

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioCapture.java

@@ -141,6 +141,10 @@ final class JigsawStudioCapture {
                     if (hiddenConnector != null) {
                         hiddenConnector.setFinalState(blockData.getAsString());
                         connectors.add(CapturedConnector.from(hiddenConnector));
+                        if (isAir(blockData.getMaterial())) {
+                            blocks.add(new CapturedBlock(x, y, z, BukkitBlockState.of(blockData), null));
+                            continue;
+                        }
                     }
                     if (hiddenConnector == null && blockData instanceof Jigsaw jigsaw) {
                         KMap<String, Object> nbt = BukkitPlatform.serializeTile(block.getLocation());
@@ -490,7 +494,7 @@ final class JigsawStudioCapture {
         };
     }
 
-    private static LocalPosition forwardPosition(
+    static LocalPosition forwardPosition(
             int x,
             int y,
             int z,

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioCaptureScheduler.java

@@ -18,6 +18,7 @@ import art.arcane.iris.structure.object.IrisObject;
 import art.arcane.iris.studio.generation.JigsawStudioGenerator;
 import art.arcane.iris.spi.IrisLogging;
 import art.arcane.iris.world.task.J;
+import org.bukkit.Bukkit;
 import org.bukkit.World;
 import org.bukkit.entity.Player;
 
@@ -122,7 +123,7 @@ final class JigsawStudioCaptureScheduler {
             }
             coordinator.accept(snapshot);
         } catch (Throwable exception) {
-            coordinator.fail("Jigsaw Studio capture failed in chunk "
+            coordinator.failPersistent("Jigsaw Studio capture failed in chunk "
                     + area.chunkX() + "," + area.chunkZ() + ": " + failureMessage(exception), exception);
         }
     }
@@ -219,7 +220,7 @@ final class JigsawStudioCaptureScheduler {
             if (!result.successful()) {
                 String failure = writeFailure(result);
                 coordinator.recordPersistentFailure(failure, result.failure().orElse(null));
-                message(player, failure);
+                message(coordinator.notifiedPlayer(), failure);
                 return;
             }
             source.invalidateStructureResources();
@@ -234,13 +235,14 @@ final class JigsawStudioCaptureScheduler {
                         + "Close and reopen this project before continuing: "
                         + failureMessage(refreshFailure));
             }
+            service.floorPainter.refresh(studio, bay.stableId());
             String cleanup = result.status() == StructureWriteResult.Status.COMMITTED_CLEANUP_REQUIRED
                     ? " The graph committed, but transaction cleanup requires operator attention in the console."
                     : "";
             String mutationNotice = unchanged ? "" : " Newer edits remain unsaved.";
             message(player, "Saved piece '" + coordinator.saveIdentity().variantKey() + "' and object '"
                     + assembly.objectKey() + "' atomically." + mutationNotice + cleanup);
-            playSaveSound(player);
+            playSaveSound(coordinator.notifiedPlayer());
             if (unchanged) {
                 service.evaluator.scheduleEvaluation(studio);
             }
@@ -250,12 +252,19 @@ final class JigsawStudioCaptureScheduler {
         } catch (Throwable exception) {
             String failure = "Jigsaw Studio save failed: " + failureMessage(exception);
             coordinator.recordPersistentFailure(failure, exception);
-            message(player, failure);
+            message(coordinator.notifiedPlayer(), failure);
         } finally {
             coordinator.complete();
         }
     }
 
+    static Player notificationTarget(Player player, UUID ownerId) {
+        if (player != null || ownerId == null) {
+            return player;
+        }
+        return Bukkit.getPlayer(ownerId);
+    }
+
     static Set<Long> requiredChunks(
             JigsawStudioBay bay,
             JigsawStudioGenerator.RenderedBay rendered
@@ -368,6 +377,10 @@ final class JigsawStudioCaptureScheduler {
             return work.player();
         }
 
+        private Player notifiedPlayer() {
+            return notificationTarget(work.player(), work.studio().generator().getRequest().ownerId());
+        }
+
         private UUID requestId() {
             return work.requestId();
         }
@@ -427,7 +440,7 @@ final class JigsawStudioCaptureScheduler {
             }
             recordPersistentFailure(failure, exception);
             complete();
-            message(player(), failure);
+            message(notifiedPlayer(), failure);
         }
 
         private void recordPersistentFailure(String failure, Throwable exception) {

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioChunkWriter.java

@@ -40,58 +40,84 @@ final class JigsawStudioChunkWriter {
     private JigsawStudioChunkWriter() {
     }
 
-    static void restoreConnectorChunk(
+    static void restoreChunkPositions(
             World world,
             JigsawStudioBay workcell,
-            List<JigsawStudioGenerator.RenderedConnector> connectors,
+            Set<LocalPosition> positions,
+            Map<LocalPosition, JigsawStudioGenerator.RenderedConnector> renderedConnectors,
             Map<LocalPosition, JigsawStudioGenerator.RenderedBlock> renderedBlocks,
             boolean connectorsVisible
     ) throws IOException {
         JigsawStudioBounds bounds = workcell.bounds();
-        for (JigsawStudioGenerator.RenderedConnector connector : connectors) {
+        BlockData air = null;
-            LocalPosition position = new LocalPosition(connector.x(), connector.y(), connector.z());
+        for (LocalPosition position : positions) {
             Block target = world.getBlockAt(
-                    bounds.originX() + connector.x(),
+                    bounds.originX() + position.x(),
-                    bounds.originY() + connector.y(),
+                    bounds.originY() + position.y(),
-                    bounds.originZ() + connector.z());
+                    bounds.originZ() + position.z());
-            if (connectorsVisible) {
+            JigsawStudioGenerator.RenderedConnector connector = renderedConnectors.get(position);
-                BlockData marker;
-                try {
-                    marker = Bukkit.createBlockData(
-                            "minecraft:jigsaw[orientation=" + connector.orientation() + "]");
-                } catch (IllegalArgumentException exception) {
-                    throw new IOException("Invalid saved connector orientation '"
-                            + connector.orientation() + "'", exception);
-                }
-                target.setBlockData(marker, false);
-                BukkitPlatform.deserializeTile(markerNbt(connector.connector()), target.getLocation());
-                continue;
-            }
             JigsawStudioGenerator.RenderedBlock renderedBlock = renderedBlocks.get(position);
-            BlockData restored;
+            if (connector != null) {
-            if (renderedBlock != null) {
+                restoreConnector(target, connector, renderedBlock, connectorsVisible);
-                if (renderedBlock.state().isCustom()
+            } else if (renderedBlock != null) {
-                        || !(renderedBlock.state().nativeHandle() instanceof BlockData blockData)) {
+                restoreRenderedBlock(target, renderedBlock);
-                    throw new IOException("Saved connector block '" + renderedBlock.state().key()
-                            + "' cannot be restored directly in Bukkit Studio");
-                }
-                restored = blockData;
             } else {
-                try {
+                if (air == null) {
-                    restored = Bukkit.createBlockData(connector.connector().getFinalState());
+                    air = Material.AIR.createBlockData();
-                } catch (IllegalArgumentException exception) {
-                    throw new IOException("Invalid saved connector final state '"
-                            + connector.connector().getFinalState() + "'", exception);
                 }
+                target.setBlockData(air, false);
             }
-            target.setBlockData(restored, false);
+        }
-            if (renderedBlock != null && renderedBlock.tileData() != null) {
+    }
-                TileData tileData = renderedBlock.tileData();
+
-                if (!tileData.isApplicable(target.getBlockData()) || !tileData.toBukkitTry(target)) {
+    private static void restoreConnector(
-                    throw new IOException("Saved connector tile data could not be restored at "
+            Block target,
-                            + target.getX() + "," + target.getY() + "," + target.getZ());
+            JigsawStudioGenerator.RenderedConnector connector,
-                }
+            JigsawStudioGenerator.RenderedBlock renderedBlock,
+            boolean connectorsVisible
+    ) throws IOException {
+        if (connectorsVisible) {
+            BlockData marker;
+            try {
+                marker = Bukkit.createBlockData(
+                        "minecraft:jigsaw[orientation=" + connector.orientation() + "]");
+            } catch (IllegalArgumentException exception) {
+                throw new IOException("Invalid saved connector orientation '"
+                        + connector.orientation() + "'", exception);
             }
+            target.setBlockData(marker, false);
+            BukkitPlatform.deserializeTile(markerNbt(connector.connector()), target.getLocation());
+            return;
+        }
+        if (renderedBlock != null) {
+            restoreRenderedBlock(target, renderedBlock);
+            return;
+        }
+        BlockData restored;
+        try {
+            restored = Bukkit.createBlockData(connector.connector().getFinalState());
+        } catch (IllegalArgumentException exception) {
+            throw new IOException("Invalid saved connector final state '"
+                    + connector.connector().getFinalState() + "'", exception);
+        }
+        target.setBlockData(restored, false);
+    }
+
+    private static void restoreRenderedBlock(
+            Block target,
+            JigsawStudioGenerator.RenderedBlock renderedBlock
+    ) throws IOException {
+        if (renderedBlock.state().isCustom()
+                || !(renderedBlock.state().nativeHandle() instanceof BlockData blockData)) {
+            throw new IOException("Saved block '" + renderedBlock.state().key()
+                    + "' cannot be restored directly in Bukkit Studio");
+        }
+        target.setBlockData(blockData, false);
+        TileData tileData = renderedBlock.tileData();
+        if (tileData != null
+                && (!tileData.isApplicable(target.getBlockData()) || !tileData.toBukkitTry(target))) {
+            throw new IOException("Saved tile data could not be restored at "
+                    + target.getX() + "," + target.getY() + "," + target.getZ());
         }
     }
 

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioConnectorPlacement.java

@@ -0,0 +1,682 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.pack.value.IrisDirection;
+import art.arcane.iris.pack.value.IrisPosition;
+import art.arcane.iris.structure.jigsaw.IrisJigsawConnector;
+import art.arcane.iris.structure.jigsaw.JigsawJoint;
+import art.arcane.iris.structure.object.IrisObjectRotation;
+import art.arcane.iris.studio.jigsaw.JigsawStudioCapture.CapturedConnector;
+import art.arcane.iris.studio.jigsaw.JigsawStudioCapture.LocalPosition;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Set;
+
+final class JigsawStudioConnectorPlacement {
+    static final double MAX_REACH = 64.0D;
+    static final String EMPTY_FINAL_STATE = "minecraft:structure_void";
+
+    private static final double EPSILON = 1.0E-4D;
+    private static final int MAX_TRAVERSAL_STEPS = 512;
+    private static final List<JigsawPlanarDirection> SIDE_ORDER = List.of(
+            JigsawPlanarDirection.NORTH,
+            JigsawPlanarDirection.EAST,
+            JigsawPlanarDirection.SOUTH,
+            JigsawPlanarDirection.WEST);
+
+    private JigsawStudioConnectorPlacement() {
+    }
+
+    static Optional<Target> target(
+            Box box,
+            Ray ray,
+            Optional<BlockClick> click,
+            Set<Cell> connectorCells,
+            boolean sneaking
+    ) {
+        Objects.requireNonNull(box, "Jigsaw connector target box");
+        Objects.requireNonNull(ray, "Jigsaw connector target ray");
+        Objects.requireNonNull(click, "Jigsaw connector target click");
+        Objects.requireNonNull(connectorCells, "Jigsaw connector cells");
+        double limit = click.map(value -> entryDistance(
+                ray,
+                new Box(value.x(), value.y(), value.z(), value.x(), value.y(), value.z()))).orElse(MAX_REACH);
+        Optional<Target> resolved = connectorTarget(ray, connectorCells, limit + EPSILON);
+        if (resolved.isEmpty() && click.isPresent()) {
+            resolved = clickTarget(box, click.get());
+        }
+        if (resolved.isEmpty()) {
+            resolved = boundaryTarget(box, ray, limit);
+        }
+        return resolved.map(target -> sneaking
+                ? new Target(target.x(), target.y(), target.z(), target.facing().reverse())
+                : target);
+    }
+
+    static Decision decideSpatial(
+            boolean primary,
+            LocalPosition target,
+            IrisDirection facing,
+            Map<LocalPosition, IrisDirection> connectors,
+            Optional<LocalPosition> selection
+    ) {
+        boolean occupied = connectors.containsKey(target);
+        Optional<LocalPosition> activeSelection = selection.filter(connectors::containsKey);
+        if (primary) {
+            if (occupied) {
+                return Decision.of(Operation.REMOVE, target);
+            }
+            return activeSelection.isPresent()
+                    ? Decision.of(Operation.CLEAR_SELECTION, activeSelection.get())
+                    : Decision.message(Operation.NONE, "No connector here. Right-click to place one.");
+        }
+        if (activeSelection.isEmpty()) {
+            return Decision.of(occupied ? Operation.SELECT : Operation.ADD, target);
+        }
+        LocalPosition selected = activeSelection.get();
+        if (selected.equals(target)) {
+            return Decision.of(connectors.get(target) == facing ? Operation.DESELECT : Operation.REORIENT, target);
+        }
+        return Decision.of(occupied ? Operation.SELECT : Operation.MOVE, target);
+    }
+
+    static Decision decidePlanar(
+            boolean primary,
+            LocalPosition target,
+            IrisDirection facing,
+            JigsawStudioCellDimensions displayDimensions,
+            JigsawPlanarTopology topology,
+            Map<LocalPosition, IrisDirection> connectors,
+            String workcellName
+    ) {
+        if (primary) {
+            IrisDirection connectorFacing = connectors.get(target);
+            if (connectorFacing == null) {
+                return Decision.message(Operation.NONE, "No connector here. Right-click a side to seat its socket.");
+            }
+            Optional<JigsawPlanarDirection> side = planarSide(connectorFacing);
+            if (side.isPresent() && topology.connects(side.get())
+                    && countFacing(connectors, connectorFacing) == 1) {
+                return Decision.message(Operation.REFUSE, workcellName + " needs its "
+                        + sideName(side.get()) + " socket; planar topology is fixed by the workcell.");
+            }
+            return Decision.of(Operation.REMOVE, target);
+        }
+        if (topology.directions().isEmpty()) {
+            return Decision.message(Operation.REFUSE, workcellName + " has no connector sockets.");
+        }
+        Optional<JigsawPlanarDirection> clicked = planarSide(facing);
+        JigsawPlanarDirection side = clicked.orElseGet(() -> nearestSide(target, displayDimensions, topology));
+        if (!topology.connects(side)) {
+            return Decision.message(Operation.REFUSE, workcellName + " connects "
+                    + describeSides(topology) + " only; its planar topology is fixed.");
+        }
+        return new Decision(Operation.RESEAT, target, side, "");
+    }
+
+    static int indexAt(List<IrisJigsawConnector> connectors, Frame frame, LocalPosition display) {
+        for (int index = 0; index < connectors.size(); index++) {
+            if (frame.display(connectors.get(index).getPosition()).equals(display)) {
+                return index;
+            }
+        }
+        return -1;
+    }
+
+    static List<IrisJigsawConnector> add(
+            List<IrisJigsawConnector> connectors,
+            Frame frame,
+            LocalPosition target,
+            IrisDirection facing,
+            IrisDirection top,
+            Identity identity,
+            CellContents contents
+    ) {
+        if (indexAt(connectors, frame, target) >= 0) {
+            throw new IllegalArgumentException("A connector already occupies " + describe(target));
+        }
+        IrisPosition position = frame.source(target);
+        IrisJigsawConnector added = new IrisJigsawConnector()
+                .setPosition(position)
+                .setDirection(frame.sourceDirection(facing))
+                .setTop(frame.sourceDirection(top))
+                .setPool(identity.pool())
+                .setName(identity.name())
+                .setTargetName(identity.targetName())
+                .setChannel("")
+                .setJoint(identity.joint())
+                .setFinalState(finalState(position, EMPTY_FINAL_STATE, contents))
+                .setSelectionPriority(0)
+                .setPlacementPriority(0);
+        List<IrisJigsawConnector> updated = copy(connectors);
+        updated.add(added);
+        return List.copyOf(updated);
+    }
+
+    static List<IrisJigsawConnector> move(
+            List<IrisJigsawConnector> connectors,
+            Frame frame,
+            LocalPosition from,
+            LocalPosition to,
+            IrisDirection facing,
+            IrisDirection top,
+            CellContents contents
+    ) {
+        int index = indexAt(connectors, frame, from);
+        if (index < 0) {
+            throw new IllegalArgumentException("No connector exists at " + describe(from));
+        }
+        if (!from.equals(to) && indexAt(connectors, frame, to) >= 0) {
+            throw new IllegalArgumentException("A connector already occupies " + describe(to));
+        }
+        List<IrisJigsawConnector> updated = copy(connectors);
+        IrisJigsawConnector moved = updated.get(index);
+        IrisPosition position = frame.source(to);
+        moved.setPosition(position)
+                .setDirection(frame.sourceDirection(facing))
+                .setTop(frame.sourceDirection(top));
+        if (!from.equals(to)) {
+            moved.setFinalState(finalState(position, moved.getFinalState(), contents));
+        }
+        return List.copyOf(updated);
+    }
+
+    static List<IrisJigsawConnector> remove(
+            List<IrisJigsawConnector> connectors,
+            Frame frame,
+            LocalPosition at
+    ) {
+        int index = indexAt(connectors, frame, at);
+        if (index < 0) {
+            throw new IllegalArgumentException("No connector exists at " + describe(at));
+        }
+        List<IrisJigsawConnector> updated = copy(connectors);
+        updated.remove(index);
+        return List.copyOf(updated);
+    }
+
+    static ReseatResult reseat(
+            List<IrisJigsawConnector> connectors,
+            Frame frame,
+            JigsawPlanarDirection displaySide,
+            Identity identity,
+            CellContents contents
+    ) {
+        IrisDirection sourceDirection = frame.sourceDirection(displaySide.irisDirection());
+        JigsawStudioCellDimensions dimensions = frame.sourceDimensions();
+        IrisPosition socket = IrisJigsawConnector.canonicalPlanarPosition(
+                new IrisPosition(dimensions.width(), dimensions.height(), dimensions.depth()),
+                sourceDirection);
+        List<IrisJigsawConnector> updated = copy(connectors);
+        int seatedIndex = -1;
+        int strays = 0;
+        for (int index = 0; index < updated.size(); index++) {
+            if (updated.get(index).getDirection() != sourceDirection) {
+                continue;
+            }
+            if (seatedIndex < 0) {
+                seatedIndex = index;
+            } else {
+                strays++;
+            }
+        }
+        if (seatedIndex < 0) {
+            updated.add(new IrisJigsawConnector()
+                    .setPosition(socket)
+                    .setDirection(sourceDirection)
+                    .setTop(IrisDirection.UP_POSITIVE_Y)
+                    .setPool(identity.pool())
+                    .setName(identity.name())
+                    .setTargetName(identity.targetName())
+                    .setChannel("")
+                    .setJoint(identity.joint())
+                    .setFinalState(finalState(socket, EMPTY_FINAL_STATE, contents))
+                    .setSelectionPriority(0)
+                    .setPlacementPriority(0));
+            return new ReseatResult(List.copyOf(updated), true, 0);
+        }
+        IrisJigsawConnector seated = updated.get(seatedIndex);
+        boolean alreadySeated = socket.equals(seated.getPosition())
+                && seated.getTop() == IrisDirection.UP_POSITIVE_Y;
+        if (alreadySeated && strays == 0) {
+            return new ReseatResult(List.copyOf(connectors), false, 0);
+        }
+        if (!socket.equals(seated.getPosition())) {
+            seated.setPosition(socket)
+                    .setFinalState(finalState(socket, seated.getFinalState(), contents));
+        }
+        seated.setTop(IrisDirection.UP_POSITIVE_Y);
+        List<IrisJigsawConnector> retained = new ArrayList<>(updated.size() - strays);
+        for (int index = 0; index < updated.size(); index++) {
+            IrisJigsawConnector connector = updated.get(index);
+            if (index == seatedIndex || connector.getDirection() != sourceDirection) {
+                retained.add(connector);
+            }
+        }
+        return new ReseatResult(List.copyOf(retained), true, strays);
+    }
+
+    static Set<LocalPosition> changedPositions(
+            List<IrisJigsawConnector> before,
+            List<IrisJigsawConnector> after,
+            Frame frame
+    ) {
+        Map<LocalPosition, CapturedConnector> previous = displayed(before, frame);
+        Map<LocalPosition, CapturedConnector> current = displayed(after, frame);
+        Set<LocalPosition> changed = new HashSet<>();
+        for (Map.Entry<LocalPosition, CapturedConnector> entry : previous.entrySet()) {
+            if (!entry.getValue().equals(current.get(entry.getKey()))) {
+                changed.add(entry.getKey());
+            }
+        }
+        for (Map.Entry<LocalPosition, CapturedConnector> entry : current.entrySet()) {
+            if (!entry.getValue().equals(previous.get(entry.getKey()))) {
+                changed.add(entry.getKey());
+            }
+        }
+        return Set.copyOf(changed);
+    }
+
+    static String describe(LocalPosition position) {
+        return position.x() + "," + position.y() + "," + position.z();
+    }
+
+    static String sideName(JigsawPlanarDirection side) {
+        return side.name().toLowerCase(Locale.ROOT);
+    }
+
+    private static Map<LocalPosition, CapturedConnector> displayed(List<IrisJigsawConnector> connectors, Frame frame) {
+        Map<LocalPosition, CapturedConnector> displayed = new HashMap<>(connectors.size());
+        for (IrisJigsawConnector connector : connectors) {
+            displayed.put(frame.display(connector.getPosition()), CapturedConnector.from(connector));
+        }
+        return displayed;
+    }
+
+    private static List<IrisJigsawConnector> copy(List<IrisJigsawConnector> connectors) {
+        List<IrisJigsawConnector> copied = new ArrayList<>(connectors.size() + 1);
+        for (IrisJigsawConnector connector : connectors) {
+            copied.add(CapturedConnector.from(connector).toConnector());
+        }
+        return copied;
+    }
+
+    private static String finalState(IrisPosition position, String whenEmpty, CellContents contents) {
+        Optional<CellContent> content = contents.at(position);
+        if (content.isEmpty()) {
+            return whenEmpty;
+        }
+        if (content.get().blockEntity()) {
+            throw new IllegalArgumentException("Connectors cannot replace the block entity at "
+                    + position.getX() + "," + position.getY() + "," + position.getZ()
+                    + "; clear that block first.");
+        }
+        return content.get().state();
+    }
+
+    private static int countFacing(Map<LocalPosition, IrisDirection> connectors, IrisDirection facing) {
+        int count = 0;
+        for (IrisDirection direction : connectors.values()) {
+            if (direction == facing) {
+                count++;
+            }
+        }
+        return count;
+    }
+
+    private static Optional<JigsawPlanarDirection> planarSide(IrisDirection direction) {
+        return switch (direction) {
+            case NORTH_NEGATIVE_Z -> Optional.of(JigsawPlanarDirection.NORTH);
+            case EAST_POSITIVE_X -> Optional.of(JigsawPlanarDirection.EAST);
+            case SOUTH_POSITIVE_Z -> Optional.of(JigsawPlanarDirection.SOUTH);
+            case WEST_NEGATIVE_X -> Optional.of(JigsawPlanarDirection.WEST);
+            case UP_POSITIVE_Y, DOWN_NEGATIVE_Y -> Optional.empty();
+        };
+    }
+
+    private static JigsawPlanarDirection nearestSide(
+            LocalPosition target,
+            JigsawStudioCellDimensions dimensions,
+            JigsawPlanarTopology topology
+    ) {
+        JigsawPlanarDirection nearest = null;
+        int nearestDistance = Integer.MAX_VALUE;
+        for (JigsawPlanarDirection side : SIDE_ORDER) {
+            if (!topology.connects(side)) {
+                continue;
+            }
+            int distance = switch (side) {
+                case NORTH -> target.z();
+                case EAST -> dimensions.width() - 1 - target.x();
+                case SOUTH -> dimensions.depth() - 1 - target.z();
+                case WEST -> target.x();
+            };
+            if (distance < nearestDistance) {
+                nearest = side;
+                nearestDistance = distance;
+            }
+        }
+        return Objects.requireNonNull(nearest, "Planar topology has no sides");
+    }
+
+    private static String describeSides(JigsawPlanarTopology topology) {
+        List<String> names = new ArrayList<>(4);
+        for (JigsawPlanarDirection side : SIDE_ORDER) {
+            if (topology.connects(side)) {
+                names.add(sideName(side));
+            }
+        }
+        if (names.size() == 1) {
+            return names.getFirst();
+        }
+        if (names.size() == 2) {
+            return names.get(0) + " and " + names.get(1);
+        }
+        return String.join(", ", names.subList(0, names.size() - 1)) + ", and " + names.getLast();
+    }
+
+    static double entryDistance(Ray ray, Box box) {
+        double near = 0.0D;
+        double far = MAX_REACH;
+        double[] origin = {ray.originX(), ray.originY(), ray.originZ()};
+        double[] direction = {ray.directionX(), ray.directionY(), ray.directionZ()};
+        double[] minimum = {box.minX(), box.minY(), box.minZ()};
+        double[] maximum = {box.maxX() + 1.0D, box.maxY() + 1.0D, box.maxZ() + 1.0D};
+        for (int axis = 0; axis < 3; axis++) {
+            if (Math.abs(direction[axis]) < 1.0E-12D) {
+                if (origin[axis] < minimum[axis] || origin[axis] >= maximum[axis]) {
+                    return MAX_REACH;
+                }
+                continue;
+            }
+            double first = (minimum[axis] - origin[axis]) / direction[axis];
+            double second = (maximum[axis] - origin[axis]) / direction[axis];
+            near = Math.max(near, Math.min(first, second));
+            far = Math.min(far, Math.max(first, second));
+        }
+        return near <= far ? near : MAX_REACH;
+    }
+
+    private static Optional<Target> connectorTarget(Ray ray, Set<Cell> cells, double limit) {
+        if (cells.isEmpty()) {
+            return Optional.empty();
+        }
+        int x = (int) Math.floor(ray.originX());
+        int y = (int) Math.floor(ray.originY());
+        int z = (int) Math.floor(ray.originZ());
+        int stepX = (int) Math.signum(ray.directionX());
+        int stepY = (int) Math.signum(ray.directionY());
+        int stepZ = (int) Math.signum(ray.directionZ());
+        double maxX = boundaryDistance(ray.originX(), ray.directionX(), x);
+        double maxY = boundaryDistance(ray.originY(), ray.directionY(), y);
+        double maxZ = boundaryDistance(ray.originZ(), ray.directionZ(), z);
+        double deltaX = stepX == 0 ? Double.POSITIVE_INFINITY : 1.0D / Math.abs(ray.directionX());
+        double deltaY = stepY == 0 ? Double.POSITIVE_INFINITY : 1.0D / Math.abs(ray.directionY());
+        double deltaZ = stepZ == 0 ? Double.POSITIVE_INFINITY : 1.0D / Math.abs(ray.directionZ());
+        for (int step = 0; step < MAX_TRAVERSAL_STEPS; step++) {
+            double distance;
+            IrisDirection entered;
+            if (maxX < maxY && maxX < maxZ) {
+                distance = maxX;
+                x += stepX;
+                maxX += deltaX;
+                entered = stepX > 0 ? IrisDirection.WEST_NEGATIVE_X : IrisDirection.EAST_POSITIVE_X;
+            } else if (maxY < maxZ) {
+                distance = maxY;
+                y += stepY;
+                maxY += deltaY;
+                entered = stepY > 0 ? IrisDirection.DOWN_NEGATIVE_Y : IrisDirection.UP_POSITIVE_Y;
+            } else {
+                distance = maxZ;
+                z += stepZ;
+                maxZ += deltaZ;
+                entered = stepZ > 0 ? IrisDirection.NORTH_NEGATIVE_Z : IrisDirection.SOUTH_POSITIVE_Z;
+            }
+            if (distance > limit) {
+                return Optional.empty();
+            }
+            if (cells.contains(new Cell(x, y, z))) {
+                return Optional.of(new Target(x, y, z, entered));
+            }
+        }
+        return Optional.empty();
+    }
+
+    private static double boundaryDistance(double origin, double direction, int cell) {
+        if (direction > 0.0D) {
+            return (cell + 1 - origin) / direction;
+        }
+        if (direction < 0.0D) {
+            return (origin - cell) / -direction;
+        }
+        return Double.POSITIVE_INFINITY;
+    }
+
+    private static Optional<Target> clickTarget(Box box, BlockClick click) {
+        if (box.contains(click.x(), click.y(), click.z())) {
+            return Optional.of(new Target(click.x(), click.y(), click.z(), click.face()));
+        }
+        int adjacentX = click.x() + click.face().x();
+        int adjacentY = click.y() + click.face().y();
+        int adjacentZ = click.z() + click.face().z();
+        if (box.contains(adjacentX, adjacentY, adjacentZ)) {
+            return Optional.of(new Target(adjacentX, adjacentY, adjacentZ, click.face().reverse()));
+        }
+        return Optional.empty();
+    }
+
+    private static Optional<Target> boundaryTarget(Box box, Ray ray, double limit) {
+        double[] origin = {ray.originX(), ray.originY(), ray.originZ()};
+        double[] direction = {ray.directionX(), ray.directionY(), ray.directionZ()};
+        double[] minimum = {box.minX(), box.minY(), box.minZ()};
+        double[] maximum = {box.maxX() + 1.0D, box.maxY() + 1.0D, box.maxZ() + 1.0D};
+        double near = Double.NEGATIVE_INFINITY;
+        double far = Double.POSITIVE_INFINITY;
+        int nearAxis = -1;
+        int farAxis = -1;
+        for (int axis = 0; axis < 3; axis++) {
+            if (Math.abs(direction[axis]) < 1.0E-12D) {
+                if (origin[axis] < minimum[axis] || origin[axis] >= maximum[axis]) {
+                    return Optional.empty();
+                }
+                continue;
+            }
+            double first = (minimum[axis] - origin[axis]) / direction[axis];
+            double second = (maximum[axis] - origin[axis]) / direction[axis];
+            double axisNear = Math.min(first, second);
+            double axisFar = Math.max(first, second);
+            if (axisNear > near) {
+                near = axisNear;
+                nearAxis = axis;
+            }
+            if (axisFar < far) {
+                far = axisFar;
+                farAxis = axis;
+            }
+        }
+        if (near > far || far < 0.0D) {
+            return Optional.empty();
+        }
+        boolean inside = near < 0.0D;
+        double distance = inside ? far - EPSILON : near + EPSILON;
+        int axis = inside ? farAxis : nearAxis;
+        if (axis < 0 || !inside && near > limit) {
+            return Optional.empty();
+        }
+        boolean positive = direction[axis] > 0.0D;
+        IrisDirection facing = axisDirection(axis, inside == positive);
+        int x = clamp((int) Math.floor(origin[0] + direction[0] * distance), box.minX(), box.maxX());
+        int y = clamp((int) Math.floor(origin[1] + direction[1] * distance), box.minY(), box.maxY());
+        int z = clamp((int) Math.floor(origin[2] + direction[2] * distance), box.minZ(), box.maxZ());
+        return Optional.of(new Target(x, y, z, facing));
+    }
+
+    private static IrisDirection axisDirection(int axis, boolean positive) {
+        return switch (axis) {
+            case 0 -> positive ? IrisDirection.EAST_POSITIVE_X : IrisDirection.WEST_NEGATIVE_X;
+            case 1 -> positive ? IrisDirection.UP_POSITIVE_Y : IrisDirection.DOWN_NEGATIVE_Y;
+            case 2 -> positive ? IrisDirection.SOUTH_POSITIVE_Z : IrisDirection.NORTH_NEGATIVE_Z;
+            default -> throw new IllegalStateException("Unreachable Jigsaw connector axis " + axis);
+        };
+    }
+
+    private static int clamp(int value, int minimum, int maximum) {
+        return Math.max(minimum, Math.min(maximum, value));
+    }
+
+    enum Operation {
+        SELECT,
+        DESELECT,
+        CLEAR_SELECTION,
+        ADD,
+        MOVE,
+        REORIENT,
+        REMOVE,
+        RESEAT,
+        REFUSE,
+        NONE
+    }
+
+    record Box(int minX, int minY, int minZ, int maxX, int maxY, int maxZ) {
+        static Box of(JigsawStudioBounds bounds, JigsawStudioCellDimensions dimensions) {
+            return new Box(
+                    bounds.originX(),
+                    bounds.originY(),
+                    bounds.originZ(),
+                    bounds.originX() + dimensions.width() - 1,
+                    bounds.originY() + dimensions.height() - 1,
+                    bounds.originZ() + dimensions.depth() - 1);
+        }
+
+        boolean contains(int x, int y, int z) {
+            return x >= minX && x <= maxX && y >= minY && y <= maxY && z >= minZ && z <= maxZ;
+        }
+
+        LocalPosition local(Target target) {
+            return new LocalPosition(target.x() - minX, target.y() - minY, target.z() - minZ);
+        }
+
+        Cell world(LocalPosition position) {
+            return new Cell(minX + position.x(), minY + position.y(), minZ + position.z());
+        }
+    }
+
+    record Ray(double originX, double originY, double originZ, double directionX, double directionY, double directionZ) {
+        Ray {
+            double length = Math.sqrt(directionX * directionX + directionY * directionY + directionZ * directionZ);
+            if (!(length > 1.0E-9D)) {
+                throw new IllegalArgumentException("Jigsaw connector ray direction cannot be zero");
+            }
+            directionX /= length;
+            directionY /= length;
+            directionZ /= length;
+        }
+    }
+
+    record BlockClick(int x, int y, int z, IrisDirection face) {
+        BlockClick {
+            Objects.requireNonNull(face, "Jigsaw connector clicked face");
+        }
+    }
+
+    record Cell(int x, int y, int z) {
+    }
+
+    record Target(int x, int y, int z, IrisDirection facing) {
+        Target {
+            Objects.requireNonNull(facing, "Jigsaw connector target facing");
+        }
+    }
+
+    record Decision(Operation operation, LocalPosition position, JigsawPlanarDirection side, String message) {
+        Decision {
+            Objects.requireNonNull(operation, "Jigsaw connector decision operation");
+            message = message == null ? "" : message;
+        }
+
+        static Decision of(Operation operation, LocalPosition position) {
+            return new Decision(operation, position, null, "");
+        }
+
+        static Decision message(Operation operation, String message) {
+            return new Decision(operation, null, null, message);
+        }
+    }
+
+    record Frame(JigsawStudioCellDimensions sourceDimensions, int quarterTurns) {
+        Frame {
+            Objects.requireNonNull(sourceDimensions, "Jigsaw connector frame dimensions");
+            quarterTurns = Math.floorMod(quarterTurns, 4);
+        }
+
+        JigsawStudioCellDimensions displayDimensions() {
+            return (quarterTurns & 1) == 0
+                    ? sourceDimensions
+                    : new JigsawStudioCellDimensions(
+                            sourceDimensions.depth(),
+                            sourceDimensions.height(),
+                            sourceDimensions.width());
+        }
+
+        LocalPosition display(IrisPosition source) {
+            return JigsawStudioCapture.forwardPosition(
+                    source.getX(),
+                    source.getY(),
+                    source.getZ(),
+                    sourceDimensions.width(),
+                    sourceDimensions.depth(),
+                    quarterTurns);
+        }
+
+        IrisPosition source(LocalPosition display) {
+            LocalPosition position = JigsawStudioCapture.inversePosition(
+                    display.x(),
+                    display.y(),
+                    display.z(),
+                    sourceDimensions.width(),
+                    sourceDimensions.depth(),
+                    quarterTurns);
+            return new IrisPosition(position.x(), position.y(), position.z());
+        }
+
+        IrisDirection sourceDirection(IrisDirection display) {
+            return quarterTurns == 0 ? display : IrisObjectRotation.of(0, 90.0D * quarterTurns, 0).rotate(display);
+        }
+
+        IrisDirection displayDirection(IrisDirection source) {
+            return quarterTurns == 0 ? source : IrisObjectRotation.of(0, -90.0D * quarterTurns, 0).rotate(source);
+        }
+    }
+
+    record Identity(String pool, String name, String targetName, JigsawJoint joint) {
+        Identity {
+            Objects.requireNonNull(pool, "Jigsaw connector default pool");
+            Objects.requireNonNull(name, "Jigsaw connector default name");
+            Objects.requireNonNull(targetName, "Jigsaw connector default target");
+            Objects.requireNonNull(joint, "Jigsaw connector default joint");
+        }
+    }
+
+    record CellContent(String state, boolean blockEntity) {
+        CellContent {
+            Objects.requireNonNull(state, "Jigsaw connector cell state");
+        }
+    }
+
+    @FunctionalInterface
+    interface CellContents {
+        Optional<CellContent> at(IrisPosition source);
+    }
+
+    record ReseatResult(List<IrisJigsawConnector> connectors, boolean changed, int removedStrays) {
+        ReseatResult {
+            connectors = List.copyOf(connectors);
+        }
+    }
+}

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioConnectorTool.java

@@ -0,0 +1,842 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.pack.loading.IrisData;
+import art.arcane.iris.pack.value.IrisDirection;
+import art.arcane.iris.pack.value.IrisPosition;
+import art.arcane.iris.platform.bukkit.BukkitPlatform;
+import art.arcane.iris.spi.IrisLogging;
+import art.arcane.iris.structure.authoring.StructureTransactionWriter;
+import art.arcane.iris.structure.authoring.StructureWriteOptions;
+import art.arcane.iris.structure.authoring.StructureWriteResult;
+import art.arcane.iris.structure.graph.StructureResourceBundleGraphCompiler;
+import art.arcane.iris.structure.jigsaw.IrisJigsawConnector;
+import art.arcane.iris.structure.jigsaw.IrisJigsawPiece;
+import art.arcane.iris.structure.jigsaw.JigsawJoint;
+import art.arcane.iris.structure.object.IrisObject;
+import art.arcane.iris.studio.generation.JigsawStudioGenerator;
+import art.arcane.iris.studio.jigsaw.JigsawStudioCapture.LocalPosition;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.BlockClick;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Box;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Cell;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.CellContent;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Decision;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Frame;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Identity;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Operation;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Ray;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.ReseatResult;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Target;
+import art.arcane.iris.studio.jigsaw.JigsawStudioMaterializer.ConnectorEditReservation;
+import art.arcane.iris.studio.jigsaw.JigsawStudioService.ActiveStudio;
+import art.arcane.iris.world.task.J;
+import art.arcane.volmlib.nativelib.terrain.NativeBlockState;
+import art.arcane.volmlib.util.hud.HudPriority;
+import art.arcane.volmlib.util.hud.HudSegment;
+import art.arcane.volmlib.util.hud.HudSlot;
+import art.arcane.volmlib.util.plugin.ComponentMessenger;
+import org.bukkit.ChatColor;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockFace;
+import org.bukkit.entity.Player;
+import org.bukkit.util.RayTraceResult;
+import org.bukkit.util.Vector;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+
+import static art.arcane.iris.studio.jigsaw.JigsawStudioGraphMutations.loadMappedLayout;
+import static art.arcane.iris.studio.jigsaw.JigsawStudioProtection.authorizeOwner;
+import static art.arcane.iris.studio.jigsaw.JigsawStudioService.AUTOSAVE_RETRY_TICKS;
+import static art.arcane.iris.studio.jigsaw.JigsawStudioService.chunkKey;
+import static art.arcane.iris.studio.jigsaw.JigsawStudioService.failureMessage;
+import static art.arcane.iris.studio.jigsaw.JigsawStudioService.message;
+import static art.arcane.iris.studio.jigsaw.JigsawStudioService.writeFailure;
+
+final class JigsawStudioConnectorTool {
+    private static final int MAX_QUEUED_ATTEMPTS = 48;
+    private static final double HOVER_REACH = 5.0D;
+    private static final String HUD_PURPOSE = "iris:jigsaw-connector";
+    private static final long HUD_MILLIS = 4000L;
+
+    private final JigsawStudioService service;
+    final Map<UUID, Selection> selections = new ConcurrentHashMap<>();
+    final Map<UUID, PendingClick> pendingClicks = new ConcurrentHashMap<>();
+
+    JigsawStudioConnectorTool(JigsawStudioService service) {
+        this.service = Objects.requireNonNull(service, "Jigsaw Studio service");
+    }
+
+    boolean handleClick(
+            Player player,
+            JigsawStudioToolPayload payload,
+            boolean primary,
+            Block clicked,
+            BlockFace face
+    ) {
+        if (player == null || payload == null) {
+            return false;
+        }
+        if (!J.isOwnedByCurrentRegion(player)) {
+            return J.runEntity(player, () -> handleClick(player, payload, primary, clicked, face));
+        }
+        ActiveStudio studio = service.studios.get(player.getWorld().getUID());
+        if (studio == null || !studio.generator().getRequest().requestId().equals(payload.requestId())) {
+            actionBar(player, ChatColor.RED + "This Connector Tool belongs to a different or closed Jigsaw Studio.");
+            return false;
+        }
+        if (!authorizeOwner(player, studio)) {
+            return false;
+        }
+        if (!primary && clicked != null && clicked.getType() == Material.JIGSAW) {
+            player.closeInventory();
+        }
+        Resolution resolution = resolve(player, studio, primary, blockClick(clicked, face));
+        if (resolution.click().isEmpty()) {
+            actionBar(player, ChatColor.YELLOW + resolution.failure());
+            return false;
+        }
+        process(player, studio, resolution.click().get(), 0);
+        return true;
+    }
+
+    Optional<Feedback> feedback(Player player, ActiveStudio studio, boolean holdingTool) {
+        Optional<Cell> selected = selectedCell(player, studio);
+        Optional<Hover> hover = Optional.empty();
+        if (holdingTool) {
+            RayTraceResult trace = player.rayTraceBlocks(HOVER_REACH);
+            Optional<BlockClick> click = trace == null
+                    ? Optional.empty()
+                    : blockClick(trace.getHitBlock(), trace.getHitBlockFace());
+            Resolution resolution = resolve(player, studio, false, click);
+            if (resolution.click().isPresent() && resolution.box() != null) {
+                ToolClick toolClick = resolution.click().get();
+                hover = Optional.of(new Hover(
+                        resolution.box().world(toolClick.target()),
+                        toolClick.facing(),
+                        resolution.existingConnector()));
+            }
+        }
+        if (selected.isEmpty() && hover.isEmpty()) {
+            return Optional.empty();
+        }
+        return Optional.of(new Feedback(selected, hover));
+    }
+
+    void clearPlayer(UUID playerId) {
+        selections.remove(playerId);
+        pendingClicks.remove(playerId);
+    }
+
+    private Optional<Cell> selectedCell(Player player, ActiveStudio studio) {
+        Selection selection = selections.get(player.getUniqueId());
+        if (selection == null || !selection.requestId().equals(studio.generator().getRequest().requestId())) {
+            return Optional.empty();
+        }
+        JigsawStudioSession session = studio.generator().getSession();
+        JigsawStudioBay workcell = session.layout().get(selection.workcellId());
+        if (workcell == null || session.activeVariant(workcell.stableId())
+                .map(JigsawStudioVariant::pieceKey)
+                .filter(selection.pieceKey()::equals)
+                .isEmpty()) {
+            return Optional.empty();
+        }
+        JigsawStudioGenerator.RenderedBay rendered = studio.generator().renderBay(workcell);
+        if (!rendered.valid() || !displayedConnectors(rendered).containsKey(selection.position())) {
+            return Optional.empty();
+        }
+        return Optional.of(Box.of(workcell.bounds(), rendered.dimensions()).world(selection.position()));
+    }
+
+    private Resolution resolve(
+            Player player,
+            ActiveStudio studio,
+            boolean primary,
+            Optional<BlockClick> click
+    ) {
+        JigsawStudioSession session = studio.generator().getSession();
+        JigsawStudioLayout layout = session.layout();
+        Location eye = player.getEyeLocation();
+        Vector direction = eye.getDirection();
+        if (direction.lengthSquared() < 1.0E-9D) {
+            return Resolution.failed("Look at a workcell to use the Connector Tool.");
+        }
+        Ray ray = new Ray(eye.getX(), eye.getY(), eye.getZ(), direction.getX(), direction.getY(), direction.getZ());
+        JigsawStudioBay workcell = targetWorkcell(layout, player.getLocation(), ray, click);
+        if (workcell == null) {
+            return Resolution.failed("Point the Connector Tool at a workcell.");
+        }
+        JigsawStudioVariant variant = session.activeVariant(workcell.stableId()).orElse(null);
+        if (variant == null) {
+            return Resolution.failed(workcell.displayName() + " has no loaded variant.");
+        }
+        if (!variant.owned()) {
+            return Resolution.failed("Variant '" + variant.pieceKey() + "' is read-only.");
+        }
+        JigsawStudioGenerator.RenderedBay rendered = studio.generator().renderBay(workcell);
+        if (!rendered.valid()) {
+            return Resolution.failed(workcell.displayName() + " cannot be edited: " + rendered.failure());
+        }
+        Box box = Box.of(workcell.bounds(), rendered.dimensions());
+        Map<LocalPosition, IrisDirection> connectors = displayedConnectors(rendered);
+        Set<Cell> cells = new HashSet<>(connectors.size());
+        for (LocalPosition position : connectors.keySet()) {
+            cells.add(box.world(position));
+        }
+        Optional<Target> target = JigsawStudioConnectorPlacement.target(box, ray, click, cells, player.isSneaking());
+        if (target.isEmpty()) {
+            return Resolution.failed("Point at a block or wall inside the "
+                    + JigsawStudioObjectResizer.describeDimensions(rendered.dimensions()) + " variant.");
+        }
+        LocalPosition position = box.local(target.get());
+        IrisDirection top = target.get().facing().isVertical()
+                ? IrisDirection.getDirection(player.getFacing())
+                : IrisDirection.UP_POSITIVE_Y;
+        ToolClick toolClick = new ToolClick(
+                studio.generator().getRequest().requestId(),
+                workcell.stableId(),
+                variant.pieceKey(),
+                session.workcellSnapshot(workcell.stableId()).loadGeneration(),
+                primary,
+                position,
+                target.get().facing(),
+                top);
+        return new Resolution(Optional.of(toolClick), box, connectors.containsKey(position), "");
+    }
+
+    private void process(Player player, ActiveStudio studio, ToolClick click, int attempt) {
+        if (!service.isCurrentRequest(studio, click.requestId())) {
+            actionBar(player, ChatColor.RED + "This Jigsaw Studio session is no longer active.");
+            return;
+        }
+        JigsawStudioSession session = studio.generator().getSession();
+        JigsawStudioBay workcell = session.layout().get(click.workcellId());
+        JigsawStudioVariant variant = workcell == null ? null : session.activeVariant(workcell.stableId()).orElse(null);
+        if (variant == null
+                || !variant.pieceKey().equals(click.pieceKey())
+                || session.workcellSnapshot(workcell.stableId()).loadGeneration() != click.loadGeneration()) {
+            actionBar(player, ChatColor.YELLOW + "The workcell changed before the connector edit ran; click again.");
+            return;
+        }
+        JigsawStudioSession.WorkcellSnapshot snapshot = session.workcellSnapshot(workcell.stableId());
+        if (snapshot.dirty() || snapshot.saveInProgress() || snapshot.switchInProgress()) {
+            queue(player, studio, click, attempt, "Saving your latest edits before changing connectors...");
+            return;
+        }
+        JigsawStudioSaveLifecycle.BayReadiness readiness = studio.population(workcell).readiness();
+        if (!readiness.ready()) {
+            if (!readiness.failure().isEmpty()) {
+                actionBar(player, ChatColor.RED + workcell.displayName() + " is not editable: " + readiness.failure());
+                return;
+            }
+            queue(player, studio, click, attempt, "Waiting for " + workcell.displayName() + " to finish loading...");
+            return;
+        }
+        JigsawStudioGenerator.RenderedBay rendered = studio.generator().renderBay(workcell);
+        if (!rendered.valid()) {
+            actionBar(player, ChatColor.RED + workcell.displayName() + " cannot be edited: " + rendered.failure());
+            return;
+        }
+        Map<LocalPosition, IrisDirection> connectors = displayedConnectors(rendered);
+        Optional<LocalPosition> selection = currentSelection(player, click);
+        Decision decision = workcell.topology().isPresent()
+                ? JigsawStudioConnectorPlacement.decidePlanar(
+                        click.primary(),
+                        click.target(),
+                        click.facing(),
+                        rendered.dimensions(),
+                        workcell.topology().get(),
+                        connectors,
+                        workcell.displayName())
+                : JigsawStudioConnectorPlacement.decideSpatial(
+                        click.primary(),
+                        click.target(),
+                        click.facing(),
+                        connectors,
+                        selection);
+        switch (decision.operation()) {
+            case SELECT -> {
+                selections.put(player.getUniqueId(), new Selection(
+                        click.requestId(), click.workcellId(), click.pieceKey(), decision.position()));
+                actionBar(player, ChatColor.AQUA + "Selected the connector at "
+                        + JigsawStudioConnectorPlacement.describe(decision.position()) + " facing "
+                        + directionName(connectors.get(decision.position()))
+                        + ChatColor.GRAY + ". Right-click a new spot to move it, the same block to deselect, or left-click to remove it.");
+            }
+            case DESELECT, CLEAR_SELECTION -> {
+                selections.remove(player.getUniqueId());
+                actionBar(player, ChatColor.GRAY + "Connector deselected.");
+            }
+            case REFUSE -> actionBar(player, ChatColor.RED + decision.message());
+            case NONE -> actionBar(player, ChatColor.GRAY + decision.message());
+            case ADD, MOVE, REORIENT, REMOVE, RESEAT -> write(
+                    player,
+                    studio,
+                    workcell,
+                    variant,
+                    new Edit(decision, click, selection),
+                    attempt);
+        }
+    }
+
+    private void write(
+            Player player,
+            ActiveStudio studio,
+            JigsawStudioBay workcell,
+            JigsawStudioVariant variant,
+            Edit edit,
+            int attempt
+    ) {
+        ConnectorEditReservation reservation = service.materializer.beginConnectorEdit(studio, workcell.stableId());
+        if (reservation.status() == JigsawStudioMaterializer.ConnectorEditStatus.BUSY) {
+            queue(player, studio, edit.click(), attempt, reservation.message());
+            return;
+        }
+        if (reservation.status() == JigsawStudioMaterializer.ConnectorEditStatus.BLOCKED) {
+            actionBar(player, ChatColor.RED + reservation.message());
+            return;
+        }
+        UUID requestId = edit.click().requestId();
+        J.a(() -> {
+            EditCommit commit = null;
+            Throwable failure = null;
+            try {
+                commit = commitEdit(studio, workcell, variant, edit);
+            } catch (Throwable exception) {
+                failure = exception;
+            }
+            EditCommit completed = commit;
+            Throwable completedFailure = failure;
+            boolean written = completed != null && completed.changed();
+            boolean scheduled = J.runEntity(
+                    player,
+                    () -> completeEdit(player, studio, edit, completed, completedFailure),
+                    0,
+                    () -> abandonEdit(requestId, written, completedFailure));
+            if (!scheduled) {
+                abandonEdit(requestId, written, completedFailure);
+            }
+        });
+    }
+
+    private EditCommit commitEdit(
+            ActiveStudio studio,
+            JigsawStudioBay workcell,
+            JigsawStudioVariant variant,
+            Edit edit
+    ) throws IOException {
+        JigsawStudioActivation.Request request = studio.generator().getRequest();
+        IrisData source = request.source();
+        Path packRoot = source.getDataFolder().toPath();
+        IrisJigsawPiece piece = source.getJigsawPieceLoader().load(variant.pieceKey(), false);
+        if (piece == null || piece.getConnectors() == null || piece.getObject() == null || piece.getObject().isBlank()) {
+            throw new IOException("Piece '" + variant.pieceKey() + "' is missing or has no object");
+        }
+        IrisObject object = source.getObjectLoader().load(piece.getObject(), false);
+        if (object == null || object.getW() < 1 || object.getH() < 1 || object.getD() < 1) {
+            throw new IOException("Object '" + piece.getObject() + "' is missing or has invalid dimensions");
+        }
+        Frame frame = new Frame(
+                new JigsawStudioCellDimensions(object.getW(), object.getH(), object.getD()),
+                variant.sourceToCanonicalQuarterTurns());
+        JigsawStudioConnectorPlacement.CellContents contents = position -> cellContent(object, position);
+        List<IrisJigsawConnector> before = List.copyOf(piece.getConnectors());
+        LocalPosition target = edit.click().target();
+        IrisDirection facing = edit.click().facing();
+        IrisDirection top = edit.click().top();
+        List<IrisJigsawConnector> after;
+        String summary;
+        Selection selection = null;
+        switch (edit.decision().operation()) {
+            case ADD -> {
+                after = JigsawStudioConnectorPlacement.add(
+                        before, frame, target, facing, top, defaultIdentity(studio, variant, before, packRoot), contents);
+                summary = "Placed a connector at " + JigsawStudioConnectorPlacement.describe(target)
+                        + " facing " + directionName(facing) + ".";
+            }
+            case MOVE -> {
+                LocalPosition from = edit.selection().orElseThrow();
+                after = JigsawStudioConnectorPlacement.move(before, frame, from, target, facing, top, contents);
+                summary = "Moved the connector from " + JigsawStudioConnectorPlacement.describe(from)
+                        + " to " + JigsawStudioConnectorPlacement.describe(target)
+                        + " facing " + directionName(facing) + ".";
+                selection = new Selection(
+                        edit.click().requestId(), edit.click().workcellId(), edit.click().pieceKey(), target);
+            }
+            case REORIENT -> {
+                after = JigsawStudioConnectorPlacement.move(before, frame, target, target, facing, top, contents);
+                summary = "Turned the connector at " + JigsawStudioConnectorPlacement.describe(target)
+                        + " to face " + directionName(facing) + ".";
+                selection = new Selection(
+                        edit.click().requestId(), edit.click().workcellId(), edit.click().pieceKey(), target);
+            }
+            case REMOVE -> {
+                after = JigsawStudioConnectorPlacement.remove(before, frame, target);
+                summary = "Removed the connector at " + JigsawStudioConnectorPlacement.describe(target) + ".";
+            }
+            case RESEAT -> {
+                JigsawPlanarDirection side = Objects.requireNonNull(edit.decision().side(), "Planar socket side");
+                ReseatResult result = JigsawStudioConnectorPlacement.reseat(
+                        before, frame, side, defaultIdentity(studio, variant, before, packRoot), contents);
+                if (!result.changed()) {
+                    return EditCommit.unchanged("The " + JigsawStudioConnectorPlacement.sideName(side)
+                            + " socket is already seated at its face center.");
+                }
+                after = result.connectors();
+                summary = "Seated the " + JigsawStudioConnectorPlacement.sideName(side) + " socket at its face center"
+                        + (result.removedStrays() == 0 ? "." : " and removed " + result.removedStrays()
+                        + " stray connector" + (result.removedStrays() == 1 ? "." : "s."));
+            }
+            default -> throw new IllegalStateException("Unsupported connector edit " + edit.decision().operation());
+        }
+        JigsawStudioCapture.requireWorkcellTopology(workcell, after, frame.quarterTurns());
+        JigsawStudioResourceBundleAssembler.Assembly assembly = JigsawStudioResourceBundleAssembler.assemble(
+                packRoot,
+                request.structureKey(),
+                variant.pieceKey(),
+                JigsawStudioResourceBundleAssembler.ownedResourceContent(
+                        packRoot,
+                        "objects/" + piece.getObject() + ".iob"),
+                after,
+                false);
+        StructureResourceBundleGraphCompiler.requireViable(assembly.bundle());
+        JigsawStudioHistoryStore historyStore = new JigsawStudioHistoryStore(packRoot, request.structureKey());
+        JigsawStudioHistoryStore.Snapshot previous = historyStore.snapshotCurrent(variant.pieceKey());
+        if (!previous.matches(assembly.bundle())) {
+            historyStore.append(previous);
+        }
+        StructureWriteResult result;
+        synchronized (service.saveLifecycleLock) {
+            result = new StructureTransactionWriter(packRoot)
+                    .write(assembly.bundle(), StructureWriteOptions.overwriteExpected(assembly.expectedManifestHash()));
+        }
+        if (!result.successful()) {
+            throw new IOException(writeFailure(result));
+        }
+        source.invalidateStructureResources();
+        return new EditCommit(
+                true,
+                loadMappedLayout(studio),
+                JigsawStudioConnectorPlacement.changedPositions(before, after, frame),
+                summary,
+                Optional.ofNullable(selection),
+                edit.decision().operation() == Operation.REMOVE ? Optional.of(target) : Optional.empty());
+    }
+
+    private void completeEdit(
+            Player player,
+            ActiveStudio studio,
+            Edit edit,
+            EditCommit commit,
+            Throwable failure
+    ) {
+        UUID requestId = edit.click().requestId();
+        if (failure != null) {
+            service.materializer.finishConnectorEdit(requestId);
+            if (!(failure instanceof IllegalArgumentException)) {
+                IrisLogging.reportError("Jigsaw Studio connector edit failed in workcell "
+                        + edit.click().workcellId(), failure);
+            }
+            message(player, "Connector edit failed: " + failureMessage(failure));
+            actionBar(player, ChatColor.RED + "Connector edit failed: " + failureMessage(failure));
+            return;
+        }
+        if (!commit.changed()) {
+            service.materializer.finishConnectorEdit(requestId);
+            actionBar(player, ChatColor.GRAY + commit.summary());
+            return;
+        }
+        if (!service.isCurrentRequest(studio, requestId)) {
+            service.materializer.finishConnectorEdit(requestId);
+            message(player, "The connector edit saved after this Studio session changed; reopen it to continue.");
+            return;
+        }
+        JigsawStudioSession session = studio.generator().getSession();
+        JigsawStudioBay workcell;
+        JigsawStudioGenerator.RenderedBay rendered;
+        try {
+            session.replaceLayout(commit.layout());
+            for (JigsawStudioBay bay : commit.layout().bays()) {
+                studio.generator().invalidateRender(bay.stableId());
+            }
+            workcell = session.layout().get(edit.click().workcellId());
+            if (workcell == null) {
+                throw new IOException("workcell '" + edit.click().workcellId() + "' left the layout");
+            }
+            rendered = studio.generator().renderBay(workcell);
+            if (!rendered.valid()) {
+                throw new IOException(rendered.failure());
+            }
+        } catch (Throwable exception) {
+            service.saveLifecycle.reopenRequiredRequests.add(requestId);
+            service.materializer.finishConnectorEdit(requestId);
+            IrisLogging.reportError("Jigsaw Studio saved a connector edit but could not refresh workcell "
+                    + edit.click().workcellId(), exception);
+            message(player, "The connector edit saved, but Studio could not refresh: "
+                    + failureMessage(exception) + ". Reopen this project before editing further.");
+            return;
+        }
+        restoreWorld(player, studio, workcell, rendered, commit,
+                session.workcellSnapshot(workcell.stableId()).connectorsVisible());
+    }
+
+    private void restoreWorld(
+            Player player,
+            ActiveStudio studio,
+            JigsawStudioBay workcell,
+            JigsawStudioGenerator.RenderedBay rendered,
+            EditCommit commit,
+            boolean connectorsVisible
+    ) {
+        Map<LocalPosition, JigsawStudioGenerator.RenderedConnector> connectors = new HashMap<>();
+        for (JigsawStudioGenerator.RenderedConnector connector : rendered.connectors()) {
+            connectors.put(new LocalPosition(connector.x(), connector.y(), connector.z()), connector);
+        }
+        Map<LocalPosition, JigsawStudioGenerator.RenderedBlock> blocks = new HashMap<>();
+        for (JigsawStudioGenerator.RenderedBlock block : rendered.blocks()) {
+            blocks.put(new LocalPosition(block.x(), block.y(), block.z()), block);
+        }
+        JigsawStudioBounds bounds = workcell.bounds();
+        Map<Long, Set<LocalPosition>> positionsByChunk = new LinkedHashMap<>();
+        for (LocalPosition position : commit.changedPositions()) {
+            positionsByChunk.computeIfAbsent(
+                    chunkKey((bounds.originX() + position.x()) >> 4, (bounds.originZ() + position.z()) >> 4),
+                    ignored -> new HashSet<>()).add(position);
+        }
+        if (positionsByChunk.isEmpty()) {
+            finishEdit(player, studio, workcell.stableId(), commit, "", null);
+            return;
+        }
+        AtomicInteger remaining = new AtomicInteger(positionsByChunk.size());
+        AtomicReference<String> failure = new AtomicReference<>("");
+        AtomicReference<Throwable> cause = new AtomicReference<>();
+        for (Map.Entry<Long, Set<LocalPosition>> entry : positionsByChunk.entrySet()) {
+            int chunkX = (int) (entry.getKey() >> 32);
+            int chunkZ = (int) entry.getKey().longValue();
+            boolean scheduled = J.runRegion(studio.world(), chunkX, chunkZ, () -> {
+                try {
+                    if (!studio.world().isChunkLoaded(chunkX, chunkZ)) {
+                        throw new IOException("workcell chunk " + chunkX + "," + chunkZ + " is not loaded");
+                    }
+                    JigsawStudioChunkWriter.restoreChunkPositions(
+                            studio.world(), workcell, entry.getValue(), connectors, blocks, connectorsVisible);
+                } catch (Throwable exception) {
+                    failure.compareAndSet("", failureMessage(exception));
+                    cause.compareAndSet(null, exception);
+                }
+                if (remaining.decrementAndGet() == 0) {
+                    scheduleFinish(player, studio, workcell.stableId(), commit, failure.get(), cause.get());
+                }
+            });
+            if (!scheduled) {
+                failure.compareAndSet("", "workcell chunk " + chunkX + "," + chunkZ
+                        + " could not be scheduled on its owning region");
+                if (remaining.decrementAndGet() == 0) {
+                    scheduleFinish(player, studio, workcell.stableId(), commit, failure.get(), cause.get());
+                }
+            }
+        }
+    }
+
+    private void scheduleFinish(
+            Player player,
+            ActiveStudio studio,
+            String workcellId,
+            EditCommit commit,
+            String failure,
+            Throwable cause
+    ) {
+        UUID requestId = studio.generator().getRequest().requestId();
+        boolean scheduled = J.runEntity(
+                player,
+                () -> finishEdit(player, studio, workcellId, commit, failure, cause),
+                0,
+                () -> {
+                    service.materializer.finishConnectorEdit(requestId);
+                    service.floorPainter.refresh(studio, workcellId);
+                });
+        if (!scheduled) {
+            service.materializer.finishConnectorEdit(requestId);
+            service.floorPainter.refresh(studio, workcellId);
+        }
+    }
+
+    private void finishEdit(
+            Player player,
+            ActiveStudio studio,
+            String workcellId,
+            EditCommit commit,
+            String failure,
+            Throwable cause
+    ) {
+        service.materializer.finishConnectorEdit(studio.generator().getRequest().requestId());
+        commit.selection().ifPresentOrElse(
+                selection -> selections.put(player.getUniqueId(), selection),
+                () -> commit.removed().ifPresent(removed -> selections.computeIfPresent(
+                        player.getUniqueId(),
+                        (ignored, current) -> current.workcellId().equals(workcellId)
+                                && current.position().equals(removed) ? null : current)));
+        service.floorPainter.refresh(studio, workcellId);
+        service.playerContext.refreshWorkcellContext(studio.worldId(), workcellId);
+        service.evaluator.scheduleEvaluation(studio);
+        if (!failure.isEmpty()) {
+            if (cause != null) {
+                IrisLogging.reportError("Jigsaw Studio could not update connector blocks in workcell " + workcellId, cause);
+            }
+            message(player, commit.summary() + " The workcell blocks could not update: " + failure
+                    + ". Visit the whole workcell and use Reset Connector Blocks.");
+            return;
+        }
+        actionBar(player, ChatColor.GREEN + commit.summary());
+        player.playSound(player.getLocation(), "minecraft:block.note_block.hat", 0.6F, 1.4F);
+    }
+
+    private void abandonEdit(UUID requestId, boolean written, Throwable failure) {
+        if (written) {
+            service.saveLifecycle.reopenRequiredRequests.add(requestId);
+        }
+        service.materializer.finishConnectorEdit(requestId);
+        if (failure != null && !(failure instanceof IllegalArgumentException)) {
+            IrisLogging.reportError("Jigsaw Studio connector edit failed after its player left", failure);
+        }
+    }
+
+    private void queue(Player player, ActiveStudio studio, ToolClick click, int attempt, String reason) {
+        int nextAttempt = attempt + 1;
+        if (nextAttempt > MAX_QUEUED_ATTEMPTS) {
+            pendingClicks.remove(player.getUniqueId());
+            actionBar(player, ChatColor.RED + "The connector edit was cancelled: " + reason);
+            return;
+        }
+        PendingClick pending = new PendingClick(click, nextAttempt);
+        PendingClick previous = pendingClicks.put(player.getUniqueId(), pending);
+        service.autosaveScheduler.expediteAutosaves(click.requestId());
+        if (previous == null || attempt == 0) {
+            actionBar(player, ChatColor.GRAY + reason);
+        }
+        boolean scheduled = J.runEntity(
+                player,
+                () -> resumePending(player, studio, pending),
+                AUTOSAVE_RETRY_TICKS,
+                () -> pendingClicks.remove(player.getUniqueId(), pending));
+        if (!scheduled) {
+            pendingClicks.remove(player.getUniqueId(), pending);
+        }
+    }
+
+    private void resumePending(Player player, ActiveStudio studio, PendingClick pending) {
+        if (!pendingClicks.remove(player.getUniqueId(), pending)) {
+            return;
+        }
+        process(player, studio, pending.click(), pending.attempt());
+    }
+
+    private Optional<LocalPosition> currentSelection(Player player, ToolClick click) {
+        Selection selection = selections.get(player.getUniqueId());
+        if (selection == null
+                || !selection.requestId().equals(click.requestId())
+                || !selection.workcellId().equals(click.workcellId())
+                || !selection.pieceKey().equals(click.pieceKey())) {
+            return Optional.empty();
+        }
+        return Optional.of(selection.position());
+    }
+
+    private Identity defaultIdentity(
+            ActiveStudio studio,
+            JigsawStudioVariant variant,
+            List<IrisJigsawConnector> existing,
+            Path packRoot
+    ) {
+        JigsawStudioActivation.Request request = studio.generator().getRequest();
+        boolean planar = variant.mode() == JigsawStudioMode.PLANAR_JIGSAW;
+        String generatedPool = request.structureKey() + "/pieces";
+        String pool;
+        if (Files.isRegularFile(packRoot.resolve("jigsaw-pools/" + generatedPool + ".json"))) {
+            pool = generatedPool;
+        } else if (!existing.isEmpty() && existing.getFirst().getPool() != null
+                && !existing.getFirst().getPool().isBlank()) {
+            pool = existing.getFirst().getPool();
+        } else if (!variant.memberships().isEmpty()) {
+            pool = variant.memberships().getFirst().poolKey();
+        } else {
+            throw new IllegalArgumentException("Variant '" + variant.pieceKey()
+                    + "' has no pool for a new connector; add it to a pool first.");
+        }
+        return new Identity(
+                pool,
+                planar ? "iris:planar" : "iris:spatial",
+                planar ? "iris:planar" : "iris:spatial",
+                planar ? JigsawJoint.ALIGNED : JigsawJoint.ROLLABLE);
+    }
+
+    private static Optional<CellContent> cellContent(IrisObject object, IrisPosition position) {
+        NativeBlockState state = object.getBlocks().get(object.getSigned(position.getX(), position.getY(), position.getZ()));
+        if (state == null || state.isAir()) {
+            return Optional.empty();
+        }
+        boolean blockEntity = object.getStates().get(object.getSigned(position.getX(), position.getY(), position.getZ())) != null;
+        return Optional.of(new CellContent(state.key(), blockEntity));
+    }
+
+    private static JigsawStudioBay targetWorkcell(
+            JigsawStudioLayout layout,
+            Location feet,
+            Ray ray,
+            Optional<BlockClick> click
+    ) {
+        if (click.isPresent()) {
+            BlockClick value = click.get();
+            JigsawStudioBay clicked = layout.findAt(value.x(), value.y(), value.z());
+            if (clicked != null) {
+                return clicked;
+            }
+            JigsawStudioBay adjacent = layout.findAt(
+                    value.x() + value.face().x(),
+                    value.y() + value.face().y(),
+                    value.z() + value.face().z());
+            if (adjacent != null) {
+                return adjacent;
+            }
+        }
+        JigsawStudioBay standing = layout.findColumn(feet.getBlockX(), feet.getBlockY(), feet.getBlockZ());
+        if (standing != null) {
+            return standing;
+        }
+        JigsawStudioBay nearest = null;
+        double nearestDistance = JigsawStudioConnectorPlacement.MAX_REACH;
+        for (JigsawStudioBay bay : layout.bays()) {
+            JigsawStudioBounds bounds = bay.bounds();
+            double distance = JigsawStudioConnectorPlacement.entryDistance(ray, Box.of(bounds, bounds.dimensions()));
+            if (distance < nearestDistance) {
+                nearest = bay;
+                nearestDistance = distance;
+            }
+        }
+        return nearest;
+    }
+
+    private static Optional<BlockClick> blockClick(Block clicked, BlockFace face) {
+        if (clicked == null || face == null) {
+            return Optional.empty();
+        }
+        return switch (face) {
+            case NORTH, SOUTH, EAST, WEST, UP, DOWN -> Optional.of(new BlockClick(
+                    clicked.getX(), clicked.getY(), clicked.getZ(), IrisDirection.getDirection(face)));
+            default -> Optional.empty();
+        };
+    }
+
+    private static Map<LocalPosition, IrisDirection> displayedConnectors(JigsawStudioGenerator.RenderedBay rendered) {
+        Map<LocalPosition, IrisDirection> connectors = new LinkedHashMap<>(rendered.connectors().size());
+        for (JigsawStudioGenerator.RenderedConnector connector : rendered.connectors()) {
+            connectors.put(new LocalPosition(connector.x(), connector.y(), connector.z()),
+                    connector.connector().getDirection());
+        }
+        return connectors;
+    }
+
+    static String directionName(IrisDirection direction) {
+        if (direction == null) {
+            return "nowhere";
+        }
+        return switch (direction) {
+            case UP_POSITIVE_Y -> "up";
+            case DOWN_NEGATIVE_Y -> "down";
+            case NORTH_NEGATIVE_Z -> "north";
+            case SOUTH_POSITIVE_Z -> "south";
+            case EAST_POSITIVE_X -> "east";
+            case WEST_NEGATIVE_X -> "west";
+        };
+    }
+
+    private static void actionBar(Player player, String text) {
+        if (BukkitPlatform.hasHud()) {
+            BukkitPlatform.hudBar().publish(player, new HudSegment(
+                    HUD_PURPOSE,
+                    HudPriority.INTERACTIVE,
+                    HUD_MILLIS,
+                    List.of(HudSlot.CENTER),
+                    text));
+            return;
+        }
+        ComponentMessenger.sendActionBarLegacy(player, text);
+    }
+
+    record Selection(UUID requestId, String workcellId, String pieceKey, LocalPosition position) {
+        Selection {
+            Objects.requireNonNull(requestId, "Jigsaw connector selection request");
+            Objects.requireNonNull(workcellId, "Jigsaw connector selection workcell");
+            Objects.requireNonNull(pieceKey, "Jigsaw connector selection piece");
+            Objects.requireNonNull(position, "Jigsaw connector selection position");
+        }
+    }
+
+    record PendingClick(ToolClick click, int attempt) {
+        PendingClick {
+            Objects.requireNonNull(click, "Jigsaw connector pending click");
+        }
+    }
+
+    record ToolClick(
+            UUID requestId,
+            String workcellId,
+            String pieceKey,
+            long loadGeneration,
+            boolean primary,
+            LocalPosition target,
+            IrisDirection facing,
+            IrisDirection top
+    ) {
+        ToolClick {
+            Objects.requireNonNull(requestId, "Jigsaw connector click request");
+            Objects.requireNonNull(workcellId, "Jigsaw connector click workcell");
+            Objects.requireNonNull(pieceKey, "Jigsaw connector click piece");
+            Objects.requireNonNull(target, "Jigsaw connector click target");
+            Objects.requireNonNull(facing, "Jigsaw connector click facing");
+            Objects.requireNonNull(top, "Jigsaw connector click top");
+        }
+    }
+
+    record Hover(Cell cell, IrisDirection facing, boolean existingConnector) {
+    }
+
+    record Feedback(Optional<Cell> selected, Optional<Hover> hover) {
+    }
+
+    private record Resolution(Optional<ToolClick> click, Box box, boolean existingConnector, String failure) {
+        private static Resolution failed(String failure) {
+            return new Resolution(Optional.empty(), null, false, failure);
+        }
+    }
+
+    private record Edit(Decision decision, ToolClick click, Optional<LocalPosition> selection) {
+    }
+
+    private record EditCommit(
+            boolean changed,
+            JigsawStudioLayout layout,
+            Set<LocalPosition> changedPositions,
+            String summary,
+            Optional<Selection> selection,
+            Optional<LocalPosition> removed
+    ) {
+        private static EditCommit unchanged(String summary) {
+            return new EditCommit(false, null, Set.of(), summary, Optional.empty(), Optional.empty());
+        }
+    }
+}

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioDetailsMenu.java

@@ -158,8 +158,11 @@ final class JigsawStudioDetailsMenu {
         }
         window.setElement(2, 0, size);
 
-        boolean lastVariant = workcell.variants().size() <= 1;
+        boolean spatial = state.mode() == JigsawStudioMode.SPATIAL_JIGSAW;
-        boolean deletionAvailable = variant.owned() && !variant.active() && !lastVariant;
+        boolean lastVariant = spatial
+                ? state.workcells().stream().mapToInt(cell -> cell.variants().size()).sum() <= 1
+                : workcell.variants().size() <= 1;
+        boolean deletionAvailable = state.canDeleteVariant(workcell, variant);
         boolean confirmed = deletionAvailable && controller.isDeleteConfirmed(
                 window.getViewer().getUniqueId(),
                 state.requestId(),
@@ -170,11 +173,11 @@ final class JigsawStudioDetailsMenu {
                 deletionAvailable ? confirmed ? Material.REDSTONE : Material.LAVA_BUCKET : Material.BARRIER,
                 deletionAvailable
                         ? confirmed ? ChatColor.RED + "Confirm Delete Variant" : ChatColor.RED + "Delete Variant"
-                        : variant.active()
+                        : !variant.owned()
-                                ? ChatColor.GRAY + "Loaded Variant Cannot Be Deleted"
+                                ? ChatColor.GRAY + "Deletion is Read-only"
                                 : lastVariant
                                         ? ChatColor.GRAY + "Last Variant Cannot Be Deleted"
-                                        : ChatColor.GRAY + "Deletion is Read-only")
+                                        : ChatColor.GRAY + "Loaded Variant Cannot Be Deleted")
                 .setEnchanted(confirmed);
         if (deletionAvailable) {
             delete.addLore(confirmed
@@ -186,10 +189,10 @@ final class JigsawStudioDetailsMenu {
                     workcell.stableId(),
                     variant.pieceKey(),
                     page));
-        } else if (variant.active()) {
+        } else if (variant.owned() && lastVariant) {
-            delete.addLore(ChatColor.GRAY + "Load another variant in this workcell first.");
-        } else if (lastVariant) {
             delete.addLore(ChatColor.GRAY + "Create another variant before deleting this one.");
+        } else if (variant.owned()) {
+            delete.addLore(ChatColor.GRAY + "Load another variant in this workcell first.");
         }
         window.setElement(4, 0, delete);
     }

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioFloorGlyph.java

@@ -0,0 +1,145 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.pack.value.IrisDirection;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+public final class JigsawStudioFloorGlyph {
+    private static final JigsawStudioFloorGlyph EMPTY = new JigsawStudioFloorGlyph(0, 0, Map.of());
+
+    private final int width;
+    private final int depth;
+    private final Map<Long, Cell> cells;
+
+    private JigsawStudioFloorGlyph(int width, int depth, Map<Long, Cell> cells) {
+        this.width = width;
+        this.depth = depth;
+        this.cells = cells;
+    }
+
+    public static JigsawStudioFloorGlyph empty() {
+        return EMPTY;
+    }
+
+    public static JigsawStudioFloorGlyph of(int width, int depth, List<Marker> markers) {
+        List<Marker> sourceMarkers = List.copyOf(Objects.requireNonNull(markers, "Jigsaw Studio floor markers"));
+        if (width < 1 || depth < 1 || sourceMarkers.isEmpty()) {
+            return EMPTY;
+        }
+        Map<Long, Cell> cells = new HashMap<>();
+        int centerX = width / 2;
+        int centerZ = depth / 2;
+        for (Marker marker : sourceMarkers) {
+            int x = clamp(marker.x(), width);
+            int z = clamp(marker.z(), depth);
+            drawLine(cells, centerX, centerZ, x, z);
+            if (!marker.direction().isVertical()) {
+                drawExtension(cells, x, z, marker.direction(), width, depth);
+            }
+        }
+        for (Marker marker : sourceMarkers) {
+            int x = clamp(marker.x(), width);
+            int z = clamp(marker.z(), depth);
+            Cell socket = switch (marker.direction()) {
+                case UP_POSITIVE_Y -> Cell.UP_SOCKET;
+                case DOWN_NEGATIVE_Y -> Cell.DOWN_SOCKET;
+                case NORTH_NEGATIVE_Z, SOUTH_POSITIVE_Z, EAST_POSITIVE_X, WEST_NEGATIVE_X -> Cell.HORIZONTAL_SOCKET;
+            };
+            cells.merge(key(x, z), socket, JigsawStudioFloorGlyph::merge);
+        }
+        return new JigsawStudioFloorGlyph(width, depth, Map.copyOf(cells));
+    }
+
+    public Cell cell(int localX, int localZ) {
+        if (localX < 0 || localZ < 0 || localX >= width || localZ >= depth) {
+            return Cell.BASE;
+        }
+        return cells.getOrDefault(key(localX, localZ), Cell.BASE);
+    }
+
+    private static void drawLine(Map<Long, Cell> cells, int startX, int startZ, int endX, int endZ) {
+        int deltaX = Math.abs(endX - startX);
+        int deltaZ = -Math.abs(endZ - startZ);
+        int stepX = startX < endX ? 1 : -1;
+        int stepZ = startZ < endZ ? 1 : -1;
+        int error = deltaX + deltaZ;
+        int x = startX;
+        int z = startZ;
+        while (true) {
+            cells.merge(key(x, z), Cell.LINE, JigsawStudioFloorGlyph::merge);
+            if (x == endX && z == endZ) {
+                return;
+            }
+            int doubled = error * 2;
+            if (doubled >= deltaZ) {
+                error += deltaZ;
+                x += stepX;
+            }
+            if (doubled <= deltaX) {
+                error += deltaX;
+                z += stepZ;
+            }
+        }
+    }
+
+    private static void drawExtension(
+            Map<Long, Cell> cells,
+            int startX,
+            int startZ,
+            IrisDirection direction,
+            int width,
+            int depth
+    ) {
+        int x = startX + direction.x();
+        int z = startZ + direction.z();
+        while (x >= 0 && z >= 0 && x < width && z < depth) {
+            cells.merge(key(x, z), Cell.LINE, JigsawStudioFloorGlyph::merge);
+            x += direction.x();
+            z += direction.z();
+        }
+    }
+
+    private static Cell merge(Cell current, Cell next) {
+        if (current == Cell.UP_SOCKET && next == Cell.DOWN_SOCKET
+                || current == Cell.DOWN_SOCKET && next == Cell.UP_SOCKET) {
+            return Cell.UP_AND_DOWN_SOCKET;
+        }
+        return next.priority() > current.priority() ? next : current;
+    }
+
+    private static int clamp(int value, int size) {
+        return Math.max(0, Math.min(size - 1, value));
+    }
+
+    private static long key(int x, int z) {
+        return ((long) x << 32) ^ (z & 0xffffffffL);
+    }
+
+    public enum Cell {
+        BASE(0),
+        LINE(1),
+        HORIZONTAL_SOCKET(2),
+        UP_SOCKET(3),
+        DOWN_SOCKET(3),
+        UP_AND_DOWN_SOCKET(4);
+
+        private final int priority;
+
+        Cell(int priority) {
+            this.priority = priority;
+        }
+
+        int priority() {
+            return priority;
+        }
+    }
+
+    public record Marker(int x, int z, IrisDirection direction) {
+        public Marker {
+            Objects.requireNonNull(direction, "Jigsaw Studio floor marker direction");
+        }
+    }
+}

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioFloorPainter.java

@@ -0,0 +1,122 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.studio.jigsaw.JigsawStudioCapture.ChunkCaptureArea;
+import art.arcane.iris.studio.jigsaw.JigsawStudioService.ActiveStudio;
+import art.arcane.iris.studio.generation.JigsawStudioGenerator;
+import art.arcane.iris.spi.IrisLogging;
+import art.arcane.iris.world.task.J;
+import art.arcane.volmlib.nativelib.terrain.NativeBlockState;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.block.data.BlockData;
+
+import java.util.Objects;
+
+import static art.arcane.iris.studio.jigsaw.JigsawStudioCapture.chunkIntersections;
+
+final class JigsawStudioFloorPainter {
+    private final JigsawStudioService service;
+
+    JigsawStudioFloorPainter(JigsawStudioService service) {
+        this.service = Objects.requireNonNull(service, "Jigsaw Studio service");
+    }
+
+    void refresh(ActiveStudio studio, String workcellId) {
+        if (studio == null || workcellId == null) {
+            return;
+        }
+        JigsawStudioBay workcell = studio.generator().getLayout().get(workcellId);
+        if (workcell == null) {
+            return;
+        }
+        for (ChunkCaptureArea area : chunkIntersections(workcell.bounds())) {
+            schedule(studio, workcellId, area.chunkX(), area.chunkZ());
+        }
+    }
+
+    void refreshAll(ActiveStudio studio) {
+        if (studio == null) {
+            return;
+        }
+        for (JigsawStudioBay workcell : studio.generator().getLayout().bays()) {
+            refresh(studio, workcell.stableId());
+        }
+    }
+
+    void refreshChunk(ActiveStudio studio, int chunkX, int chunkZ) {
+        if (studio == null) {
+            return;
+        }
+        int chunkMinimumX = chunkX << 4;
+        int chunkMinimumZ = chunkZ << 4;
+        for (JigsawStudioBay workcell : studio.generator().getLayout().bays()) {
+            if (workcell.bounds().intersectsHorizontal(
+                    chunkMinimumX,
+                    chunkMinimumZ,
+                    chunkMinimumX + 15,
+                    chunkMinimumZ + 15)) {
+                schedule(studio, workcell.stableId(), chunkX, chunkZ);
+            }
+        }
+    }
+
+    static int paintFloorChunk(
+            World world,
+            JigsawStudioGenerator generator,
+            JigsawStudioBay workcell,
+            int chunkX,
+            int chunkZ
+    ) {
+        JigsawStudioBounds bounds = workcell.bounds();
+        int minimumX = Math.max(bounds.originX(), chunkX << 4);
+        int maximumX = Math.min(bounds.maxX(), (chunkX << 4) + 15);
+        int minimumZ = Math.max(bounds.originZ(), chunkZ << 4);
+        int maximumZ = Math.min(bounds.maxZ(), (chunkZ << 4) + 15);
+        if (minimumX > maximumX || minimumZ > maximumZ) {
+            return 0;
+        }
+        JigsawStudioFloorGlyph glyph = generator.floorGlyph(workcell);
+        int floorY = bounds.originY() - 1;
+        int changed = 0;
+        for (int worldX = minimumX; worldX <= maximumX; worldX++) {
+            for (int worldZ = minimumZ; worldZ <= maximumZ; worldZ++) {
+                JigsawStudioFloorGlyph.Cell cell = glyph.cell(
+                        worldX - bounds.originX(),
+                        worldZ - bounds.originZ());
+                NativeBlockState state = generator.floorState(cell);
+                if (!(state.nativeHandle() instanceof BlockData expected)) {
+                    throw new IllegalStateException("Jigsaw Studio floor block '" + state.key()
+                            + "' has no Bukkit block-data representation");
+                }
+                Block block = world.getBlockAt(worldX, floorY, worldZ);
+                if (!block.getBlockData().equals(expected)) {
+                    block.setBlockData(expected, false);
+                    changed++;
+                }
+            }
+        }
+        return changed;
+    }
+
+    private void schedule(ActiveStudio studio, String workcellId, int chunkX, int chunkZ) {
+        J.runRegion(studio.world(), chunkX, chunkZ, () -> paint(studio, workcellId, chunkX, chunkZ));
+    }
+
+    private void paint(ActiveStudio studio, String workcellId, int chunkX, int chunkZ) {
+        if (!service.enabled
+                || service.studios.get(studio.worldId()) != studio
+                || !studio.world().isChunkLoaded(chunkX, chunkZ)) {
+            return;
+        }
+        JigsawStudioBay workcell = studio.generator().getLayout().get(workcellId);
+        if (workcell == null) {
+            return;
+        }
+        try {
+            paintFloorChunk(studio.world(), studio.generator(), workcell, chunkX, chunkZ);
+        } catch (Throwable exception) {
+            IrisLogging.reportError("Jigsaw Studio could not refresh the connector floor of workcell "
+                    + workcellId + " in chunk " + chunkX + "," + chunkZ, exception);
+        }
+    }
+}

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioGraphMapper.java

@@ -44,13 +44,7 @@ public final class JigsawStudioGraphMapper {
                 ? JigsawStudioMode.PLANAR_JIGSAW
                 : JigsawStudioMode.SPATIAL_JIGSAW;
         JigsawStudioVariantCatalog catalog = catalog(data, structure, mode);
-        IrisPosition configuredCell = structure.getCellSize();
+        JigsawStudioCellDimensions dimensions = configuredCellDimensions(structure);
-        JigsawStudioCellDimensions dimensions = configuredCell == null
-                ? new JigsawStudioCellDimensions(15, 15, 15)
-                : new JigsawStudioCellDimensions(
-                        Math.max(1, configuredCell.getX()),
-                        Math.max(1, configuredCell.getY()),
-                        Math.max(1, configuredCell.getZ()));
         if (mode == JigsawStudioMode.SPATIAL_JIGSAW) {
             dimensions = expandSpatialDimensions(data, catalog, dimensions);
             return JigsawStudioLayout.createSpatial(
@@ -129,26 +123,54 @@ public final class JigsawStudioGraphMapper {
         if (data.getObjectLoader() == null) {
             return configured;
         }
-        int width = configured.width();
+        SpatialExtent extent = SpatialExtent.of(configured);
-        int height = configured.height();
-        int depth = configured.depth();
         for (JigsawStudioVariant variant : catalog.spatialVariants()) {
             IrisObject object = data.getObjectLoader().load(variant.objectKey());
-            if (object == null) {
+            if (object != null) {
+                extent = extent.include(object.getW(), object.getH(), object.getD(), variant.rotatable());
+            }
+        }
+        return new JigsawStudioCellDimensions((int) extent.width(), (int) extent.height(), (int) extent.depth());
+    }
+
+    static JigsawStudioCellDimensions configuredCellDimensions(IrisStructure structure) {
+        IrisPosition configuredCell = structure.getCellSize();
+        return configuredCell == null
+                ? new JigsawStudioCellDimensions(15, 15, 15)
+                : new JigsawStudioCellDimensions(
+                        Math.max(1, configuredCell.getX()),
+                        Math.max(1, configuredCell.getY()),
+                        Math.max(1, configuredCell.getZ()));
+    }
+
+    static String spatialFootprintFailure(
+            IrisData data,
+            JigsawStudioCellDimensions configured,
+            JigsawStudioVariantCatalog catalog,
+            SpatialChange change
+    ) {
+        SpatialExtent extent = SpatialExtent.of(configured);
+        for (JigsawStudioVariant variant : catalog.spatialVariants()) {
+            if (variant.pieceKey().equals(change.pieceKey())) {
                 continue;
             }
-            int objectWidth = object.getW();
+            IrisObject object = data.getObjectLoader() == null ? null : data.getObjectLoader().load(variant.objectKey());
-            int objectDepth = object.getD();
+            if (object != null) {
-            if (variant.rotatable()) {
+                extent = extent.include(object.getW(), object.getH(), object.getD(), variant.rotatable());
-                int horizontalSpan = Math.max(objectWidth, objectDepth);
-                objectWidth = horizontalSpan;
-                objectDepth = horizontalSpan;
             }
-            width = Math.max(width, objectWidth);
-            height = Math.max(height, object.getH());
-            depth = Math.max(depth, objectDepth);
         }
-        return new JigsawStudioCellDimensions(width, height, depth);
+        JigsawStudioCellDimensions changed = change.dimensions();
+        extent = extent.include(changed.width(), changed.height(), changed.depth(), change.rotatable());
+        long volume = extent.width() * extent.height() * extent.depth();
+        if (extent.width() <= JigsawStudioCellDimensions.MAX_HORIZONTAL_AXIS
+                && extent.depth() <= JigsawStudioCellDimensions.MAX_HORIZONTAL_AXIS
+                && extent.height() <= JigsawStudioCellDimensions.MAX_HEIGHT
+                && volume <= JigsawStudioCellDimensions.MAX_VOLUME) {
+            return "";
+        }
+        return "Spatial workcells would grow to " + extent.width() + "x" + extent.height() + "x" + extent.depth()
+                + " (" + volume + " blocks), past the " + JigsawStudioCellDimensions.MAX_VOLUME
+                + "-block workcell limit. Make this variant smaller or keep rotation disabled.";
     }
 
     private static void traversePools(
@@ -378,4 +400,25 @@ public final class JigsawStudioGraphMapper {
             return new OwnedResources(Set.of(), Set.of(), Set.of(), false);
         }
     }
+
+    record SpatialChange(String pieceKey, JigsawStudioCellDimensions dimensions, boolean rotatable) {
+        SpatialChange {
+            Objects.requireNonNull(pieceKey, "Spatial change piece key");
+            Objects.requireNonNull(dimensions, "Spatial change dimensions");
+        }
+    }
+
+    private record SpatialExtent(long width, long height, long depth) {
+        static SpatialExtent of(JigsawStudioCellDimensions dimensions) {
+            return new SpatialExtent(dimensions.width(), dimensions.height(), dimensions.depth());
+        }
+
+        SpatialExtent include(int objectWidth, int objectHeight, int objectDepth, boolean rotatable) {
+            int horizontalSpan = Math.max(objectWidth, objectDepth);
+            return new SpatialExtent(
+                    Math.max(width, rotatable ? horizontalSpan : objectWidth),
+                    Math.max(height, objectHeight),
+                    Math.max(depth, rotatable ? horizontalSpan : objectDepth));
+        }
+    }
 }

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioGraphMutations.java

@@ -199,6 +199,7 @@ final class JigsawStudioGraphMutations {
         for (JigsawStudioBay workcell : result.layout().bays()) {
             service.playerContext.refreshWorkcellContext(studio.worldId(), workcell.stableId());
         }
+        service.floorPainter.refreshAll(studio);
         service.evaluator.scheduleEvaluation(studio);
         message(player, result.message());
         finishGraphMutation(requestId);
@@ -273,15 +274,20 @@ final class JigsawStudioGraphMutations {
             String failure,
             Throwable cause
     ) {
-        boolean scheduled = J.runEntity(
+        Runnable abandon = () -> {
-                player,
-                () -> completeLiveRelayout(player, studio, requestId, result, failure, cause));
-        if (!scheduled) {
             service.saveLifecycle.reopenRequiredRequests.add(requestId);
             finishGraphMutation(requestId);
             if (cause != null) {
                 IrisLogging.reportError(cause);
             }
+        };
+        boolean scheduled = J.runEntity(
+                player,
+                () -> completeLiveRelayout(player, studio, requestId, result, failure, cause),
+                0,
+                abandon);
+        if (!scheduled) {
+            abandon.run();
         }
     }
 

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioLayout.java

@@ -15,6 +15,7 @@ public final class JigsawStudioLayout {
     public static final int PLANAR_GAP = 1;
     public static final int MAX_VARIANTS = 512;
     public static final String SPATIAL_WORKCELL_ID = "workcell/spatial";
+    public static final int COLUMN_HEADROOM = 4;
 
     private static final int FIRST_ORIGIN = 16;
     private static final JigsawStudioControlPosition CONTROL_POSITION =
@@ -208,6 +209,18 @@ public final class JigsawStudioLayout {
         return null;
     }
 
+    public JigsawStudioBay findColumn(int worldX, int worldY, int worldZ) {
+        for (JigsawStudioBay bay : bays) {
+            JigsawStudioBounds bounds = bay.bounds();
+            if (worldX >= bounds.originX() && worldX <= bounds.maxX()
+                    && worldZ >= bounds.originZ() && worldZ <= bounds.maxZ()
+                    && worldY >= bounds.originY() - 1 && worldY <= bounds.maxY() + COLUMN_HEADROOM) {
+                return bay;
+            }
+        }
+        return null;
+    }
+
     public List<JigsawStudioVariant> variants(JigsawStudioBay workcell) {
         JigsawStudioBay activeWorkcell = requireWorkcell(workcell);
         if (activeWorkcell.kind() == JigsawStudioBayKind.SPATIAL_WORKCELL) {
@@ -276,7 +289,7 @@ public final class JigsawStudioLayout {
 
     private JigsawStudioBay requireWorkcell(JigsawStudioBay workcell) {
         JigsawStudioBay activeWorkcell = Objects.requireNonNull(workcell, "Jigsaw Studio workcell");
-        if (byStableId.get(activeWorkcell.stableId()) != activeWorkcell) {
+        if (!activeWorkcell.equals(byStableId.get(activeWorkcell.stableId()))) {
             throw new IllegalArgumentException("Workcell does not belong to this Jigsaw Studio layout");
         }
         return activeWorkcell;

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioMainMenu.java

@@ -6,6 +6,7 @@ import art.arcane.volmlib.util.inventorygui.UIWindow;
 import org.bukkit.ChatColor;
 import org.bukkit.Material;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
 
@@ -27,6 +28,9 @@ import static art.arcane.iris.studio.jigsaw.JigsawStudioMenuFormat.workcellStatu
 import static art.arcane.iris.studio.jigsaw.JigsawStudioMenuFormat.yesNo;
 
 final class JigsawStudioMainMenu {
+    static final int WORKCELL_ROW_CAPACITY = 6;
+    static final int WORKCELLS_PER_PAGE = 5;
+
     private final JigsawStudioMenuController controller;
 
     JigsawStudioMainMenu(JigsawStudioMenuController controller) {
@@ -103,51 +107,113 @@ final class JigsawStudioMainMenu {
     }
 
     private void addWorkcells(UIWindow window, JigsawStudioMenuState state, String selectedWorkcellId) {
-        int count = state.workcells().size();
+        List<JigsawStudioMenuState.Workcell> workcells = state.workcells();
-        int start = count == 1 ? 0 : -(count / 2);
+        int viewedIndex = 0;
-        for (int index = 0; index < count; index++) {
+        for (int index = 0; index < workcells.size(); index++) {
-            JigsawStudioMenuState.Workcell workcell = state.workcells().get(index);
+            if (workcells.get(index).stableId().equals(selectedWorkcellId)) {
-            boolean selected = workcell.stableId().equals(selectedWorkcellId);
+                viewedIndex = index;
-            UIElement element = element(
-                    "workcell-" + index,
-                    workcellMaterial(workcell, selected),
-                    (selected ? ChatColor.AQUA : workcell.enabled() ? ChatColor.WHITE : ChatColor.GRAY)
-                            + safe(workcell.displayName()))
-                    .setEnchanted(selected);
-            element.addLore(workcell.enabled()
-                    ? ChatColor.GREEN + "Enabled"
-                    : ChatColor.RED + "Disabled for assembly and export");
-            if (!workcell.canonicalName().equals(workcell.displayName())) {
-                element.addLore(ChatColor.GRAY + "Solver role: " + safe(workcell.canonicalName()));
             }
-            element.addLore(ChatColor.GRAY + "Capacity: " + dimensions(workcell.capacity()));
-            element.addLore(ChatColor.GRAY + "Variants: " + workcell.variants().size());
-            JigsawStudioMenuState.Variant active = workcell.activeVariant();
-            element.addLore(ChatColor.GRAY + "Loaded: "
-                    + (active == null ? "None" : safe(active.displayName())));
-            element.addLore(workcellStatus(workcell));
-            element.addLore(ChatColor.GRAY + "Connector blocks: "
-                    + (workcell.connectorsVisible() ? "Visible" : "Hidden"));
-            element.addLore(ChatColor.YELLOW + "Left-click to select and teleport");
-            element.addLore(ChatColor.YELLOW + "Right-click for workcell settings");
-            if (workcell.dirty() && !workcell.saving()) {
-                element.addLore(ChatColor.GOLD + "Shift-left: Flush Autosave Now");
-                element.onShiftLeftClick(clicked -> controller.flushNow(
-                        window.getViewer(), state.requestId(), workcell.stableId()));
-            }
-            element.onLeftClick(clicked -> controller.selectWorkcell(
-                    window.getViewer(),
-                    state.requestId(),
-                    workcell.stableId()));
-            element.onRightClick(clicked -> J.runEntity(
-                    window.getViewer(),
-                    () -> controller.openWorkcellSettings(
-                            window.getViewer(),
-                            state.requestId(),
-                            workcell.stableId()),
-                    1));
-            window.setElement(start + index, 0, element);
         }
+        WorkcellRow row = workcellRow(workcells.size(), viewedIndex);
+        for (int position = 0; position < row.indices().size(); position++) {
+            int index = row.indices().get(position);
+            JigsawStudioMenuState.Workcell workcell = workcells.get(index);
+            window.setElement(row.slots().get(position), 0, workcellElement(
+                    window,
+                    state,
+                    workcell,
+                    index,
+                    workcell.stableId().equals(selectedWorkcellId)));
+        }
+        if (row.previousTarget() >= 0) {
+            JigsawStudioMenuState.Workcell target = workcells.get(row.previousTarget());
+            UIElement previous = element("workcells-previous", Material.ARROW, ChatColor.YELLOW + "Previous Workcells");
+            previous.addLore(ChatColor.GRAY + "Workcells " + (row.previousTarget() + 1) + "-"
+                    + (row.previousTarget() + WORKCELLS_PER_PAGE) + " of " + workcells.size());
+            previous.onLeftClick(clicked -> controller.refreshMain(
+                    window.getViewer(), state.requestId(), target.stableId(), 0));
+            window.setElement(-4, 0, previous);
+        }
+        if (row.nextTarget() >= 0) {
+            JigsawStudioMenuState.Workcell target = workcells.get(row.nextTarget());
+            UIElement next = element("workcells-next", Material.ARROW, ChatColor.YELLOW + "Next Workcells");
+            next.addLore(ChatColor.GRAY + "Workcells " + (row.nextTarget() + 1) + "-"
+                    + Math.min(workcells.size(), row.nextTarget() + WORKCELLS_PER_PAGE)
+                    + " of " + workcells.size());
+            next.onLeftClick(clicked -> controller.refreshMain(
+                    window.getViewer(), state.requestId(), target.stableId(), 0));
+            window.setElement(2, 0, next);
+        }
+    }
+
+    static WorkcellRow workcellRow(int count, int viewedIndex) {
+        List<Integer> indices = new ArrayList<>(Math.min(count, WORKCELL_ROW_CAPACITY));
+        List<Integer> slots = new ArrayList<>(Math.min(count, WORKCELL_ROW_CAPACITY));
+        if (count <= WORKCELL_ROW_CAPACITY) {
+            int start = count == 1 ? 0 : -(count / 2);
+            for (int index = 0; index < count; index++) {
+                indices.add(index);
+                slots.add(start + index);
+            }
+            return new WorkcellRow(indices, slots, -1, -1);
+        }
+        int page = Math.max(0, Math.min(viewedIndex, count - 1)) / WORKCELLS_PER_PAGE;
+        int first = page * WORKCELLS_PER_PAGE;
+        for (int offset = 0; offset < WORKCELLS_PER_PAGE && first + offset < count; offset++) {
+            indices.add(first + offset);
+            slots.add(-3 + offset);
+        }
+        int previous = page == 0 ? -1 : first - WORKCELLS_PER_PAGE;
+        int next = first + WORKCELLS_PER_PAGE < count ? first + WORKCELLS_PER_PAGE : -1;
+        return new WorkcellRow(indices, slots, previous, next);
+    }
+
+    private UIElement workcellElement(
+            UIWindow window,
+            JigsawStudioMenuState state,
+            JigsawStudioMenuState.Workcell workcell,
+            int index,
+            boolean selected
+    ) {
+        UIElement element = element(
+                "workcell-" + index,
+                workcellMaterial(workcell, selected),
+                (selected ? ChatColor.AQUA : workcell.enabled() ? ChatColor.WHITE : ChatColor.GRAY)
+                        + safe(workcell.displayName()))
+                .setEnchanted(selected);
+        element.addLore(workcell.enabled()
+                ? ChatColor.GREEN + "Enabled"
+                : ChatColor.RED + "Disabled for assembly and export");
+        if (!workcell.canonicalName().equals(workcell.displayName())) {
+            element.addLore(ChatColor.GRAY + "Solver role: " + safe(workcell.canonicalName()));
+        }
+        element.addLore(ChatColor.GRAY + "Capacity: " + dimensions(workcell.capacity()));
+        element.addLore(ChatColor.GRAY + "Variants: " + workcell.variants().size());
+        JigsawStudioMenuState.Variant active = workcell.activeVariant();
+        element.addLore(ChatColor.GRAY + "Loaded: "
+                + (active == null ? "None" : safe(active.displayName())));
+        element.addLore(workcellStatus(workcell));
+        element.addLore(ChatColor.GRAY + "Connector blocks: "
+                + (workcell.connectorsVisible() ? "Visible" : "Hidden"));
+        element.addLore(ChatColor.YELLOW + "Left-click to select and teleport");
+        element.addLore(ChatColor.YELLOW + "Right-click for workcell settings");
+        if (workcell.dirty() && !workcell.saving()) {
+            element.addLore(ChatColor.GOLD + "Shift-left: Flush Autosave Now");
+            element.onShiftLeftClick(clicked -> controller.flushNow(
+                    window.getViewer(), state.requestId(), workcell.stableId()));
+        }
+        element.onLeftClick(clicked -> controller.selectWorkcell(
+                window.getViewer(),
+                state.requestId(),
+                workcell.stableId()));
+        element.onRightClick(clicked -> J.runEntity(
+                window.getViewer(),
+                () -> controller.openWorkcellSettings(
+                        window.getViewer(),
+                        state.requestId(),
+                        workcell.stableId()),
+                1));
+        return element;
     }
 
     private void addVariants(
@@ -283,4 +349,11 @@ final class JigsawStudioMainMenu {
                 window.getViewer(), state.requestId(), workcell.stableId(), 0));
         window.setElement(4, 5, toolbox);
     }
+
+    record WorkcellRow(List<Integer> indices, List<Integer> slots, int previousTarget, int nextTarget) {
+        WorkcellRow {
+            indices = List.copyOf(indices);
+            slots = List.copyOf(slots);
+        }
+    }
 }

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioMaterializer.java

@@ -6,7 +6,9 @@ import art.arcane.iris.studio.jigsaw.JigsawStudioService.ActiveStudio;
 import art.arcane.iris.studio.generation.JigsawStudioGenerator;
 import art.arcane.iris.spi.IrisLogging;
 import art.arcane.iris.world.task.J;
+import org.bukkit.Material;
 import org.bukkit.World;
+import org.bukkit.block.Block;
 import org.bukkit.entity.Player;
 
 import java.io.IOException;
@@ -24,7 +26,7 @@ import java.util.concurrent.atomic.AtomicReference;
 
 import static art.arcane.iris.studio.jigsaw.JigsawStudioCapture.chunkIntersections;
 import static art.arcane.iris.studio.jigsaw.JigsawStudioChunkWriter.hydrateChunk;
-import static art.arcane.iris.studio.jigsaw.JigsawStudioChunkWriter.restoreConnectorChunk;
+import static art.arcane.iris.studio.jigsaw.JigsawStudioChunkWriter.restoreChunkPositions;
 import static art.arcane.iris.studio.jigsaw.JigsawStudioChunkWriter.validateMaterialization;
 import static art.arcane.iris.studio.jigsaw.JigsawStudioChunkWriter.writeMaterializedChunk;
 import static art.arcane.iris.studio.jigsaw.JigsawStudioService.chunkKey;
@@ -139,6 +141,51 @@ final class JigsawStudioMaterializer {
         }
     }
 
+    ConnectorEditReservation beginConnectorEdit(ActiveStudio studio, String workcellId) {
+        UUID requestId = studio.generator().getRequest().requestId();
+        service.tileWatcher.finalizeJigsawTileWatches(requestId);
+        JigsawStudioSession session = studio.generator().getSession();
+        synchronized (service.saveLifecycleLock) {
+            if (!service.isCurrentRequest(studio, requestId)) {
+                return ConnectorEditReservation.blocked("This Jigsaw Studio session is no longer active.");
+            }
+            if (service.saveLifecycle.closingRequests.contains(requestId)) {
+                return ConnectorEditReservation.blocked("This Jigsaw Studio is closing and cannot edit connectors.");
+            }
+            if (service.saveLifecycle.reopenRequiredRequests.contains(requestId)) {
+                return ConnectorEditReservation.blocked("Close and reopen Jigsaw Studio before editing connectors.");
+            }
+            if (session.layout().get(workcellId) == null) {
+                return ConnectorEditReservation.blocked("The targeted workcell no longer exists.");
+            }
+            JigsawStudioSession.WorkcellSnapshot snapshot = session.workcellSnapshot(workcellId);
+            if (snapshot.dirty() || snapshot.saveInProgress()
+                    || service.saveLifecycle.savesInProgress.contains(requestId)) {
+                return ConnectorEditReservation.busy("Saving your latest edits before changing connectors...");
+            }
+            if (service.graphMutations.graphMutationsInProgress.contains(requestId)) {
+                return ConnectorEditReservation.busy("Waiting for the current graph update before changing connectors...");
+            }
+            if (service.saveLifecycle.exportsInProgress.contains(requestId)) {
+                return ConnectorEditReservation.busy("Waiting for the current export before changing connectors...");
+            }
+            if (session.operationInProgress()) {
+                return ConnectorEditReservation.busy("Waiting for the current workcell operation before changing connectors...");
+            }
+            if (service.tileWatcher.hasJigsawTileWatch(requestId)) {
+                return ConnectorEditReservation.busy("Waiting for the vanilla jigsaw-block editor to close...");
+            }
+            if (!materializationsInProgress.add(requestId)) {
+                return ConnectorEditReservation.busy("Waiting for the current variant load or connector edit to finish...");
+            }
+            return ConnectorEditReservation.started();
+        }
+    }
+
+    void finishConnectorEdit(UUID requestId) {
+        finishMaterialization(requestId);
+    }
+
     boolean scheduleConnectorRepair(
             Player player,
             ActiveStudio studio,
@@ -146,39 +193,55 @@ final class JigsawStudioMaterializer {
             JigsawStudioGenerator.RenderedBay rendered,
             boolean connectorsVisible
     ) {
-        Map<Long, List<JigsawStudioGenerator.RenderedConnector>> connectorsByChunk = new HashMap<>();
         JigsawStudioBounds bounds = workcell.bounds();
+        JigsawStudioBounds variantBounds = new JigsawStudioBounds(
+                bounds.originX(),
+                bounds.originY(),
+                bounds.originZ(),
+                rendered.dimensions());
+        Map<LocalPosition, JigsawStudioGenerator.RenderedConnector> renderedConnectors = new HashMap<>();
         for (JigsawStudioGenerator.RenderedConnector connector : rendered.connectors()) {
-            int worldX = bounds.originX() + connector.x();
+            renderedConnectors.put(new LocalPosition(connector.x(), connector.y(), connector.z()), connector);
-            int worldZ = bounds.originZ() + connector.z();
-            connectorsByChunk.computeIfAbsent(
-                    chunkKey(worldX >> 4, worldZ >> 4),
-                    ignored -> new ArrayList<>()).add(connector);
         }
-        AtomicInteger remaining = new AtomicInteger(connectorsByChunk.size());
-        AtomicReference<String> failure = new AtomicReference<>("");
-        AtomicReference<Throwable> cause = new AtomicReference<>();
-        AtomicBoolean scheduledAny = new AtomicBoolean(false);
         Map<LocalPosition, JigsawStudioGenerator.RenderedBlock> renderedBlocks = new HashMap<>();
         for (JigsawStudioGenerator.RenderedBlock block : rendered.blocks()) {
             renderedBlocks.put(new LocalPosition(block.x(), block.y(), block.z()), block);
         }
-        for (Map.Entry<Long, List<JigsawStudioGenerator.RenderedConnector>> entry
+        List<ChunkCaptureArea> areas = chunkIntersections(variantBounds);
-                : connectorsByChunk.entrySet()) {
+        AtomicInteger remaining = new AtomicInteger(areas.size());
-            int chunkX = (int) (entry.getKey() >> 32);
+        AtomicInteger cleared = new AtomicInteger();
-            int chunkZ = (int) entry.getKey().longValue();
+        AtomicReference<String> failure = new AtomicReference<>("");
+        AtomicReference<Throwable> cause = new AtomicReference<>();
+        AtomicBoolean scheduledAny = new AtomicBoolean(false);
+        for (ChunkCaptureArea area : areas) {
+            int chunkX = area.chunkX();
+            int chunkZ = area.chunkZ();
             boolean scheduled = J.runRegion(studio.world(), chunkX, chunkZ, () -> {
                 try {
                     if (!studio.world().isChunkLoaded(chunkX, chunkZ)) {
                         throw new IOException("connector chunk " + chunkX + "," + chunkZ
                                 + " is not loaded");
                     }
-                    restoreConnectorChunk(
+                    Set<LocalPosition> strays = strayMarkerPositions(
+                            studio.world(),
+                            variantBounds,
+                            area,
+                            renderedConnectors.keySet(),
+                            connectorsVisible);
+                    Set<LocalPosition> positions = new HashSet<>(strays);
+                    for (LocalPosition position : renderedConnectors.keySet()) {
+                        if (area.contains(position.x(), position.z())) {
+                            positions.add(position);
+                        }
+                    }
+                    restoreChunkPositions(
                             studio.world(),
                             workcell,
-                            entry.getValue(),
+                            positions,
+                            renderedConnectors,
                             renderedBlocks,
                             connectorsVisible);
+                    cleared.addAndGet(strays.size());
                 } catch (Throwable exception) {
                     failure.compareAndSet("", failureMessage(exception));
                     cause.compareAndSet(null, exception);
@@ -188,6 +251,7 @@ final class JigsawStudioMaterializer {
                             player,
                             studio,
                             rendered.connectors().size(),
+                            cleared.get(),
                             failure.get(),
                             cause.get());
                 }
@@ -202,6 +266,7 @@ final class JigsawStudioMaterializer {
                             player,
                             studio,
                             rendered.connectors().size(),
+                            cleared.get(),
                             failure.get(),
                             cause.get());
                 }
@@ -213,31 +278,61 @@ final class JigsawStudioMaterializer {
         return scheduledAny.get();
     }
 
+    static Set<LocalPosition> strayMarkerPositions(
+            World world,
+            JigsawStudioBounds variantBounds,
+            ChunkCaptureArea area,
+            Set<LocalPosition> savedConnectors,
+            boolean connectorsVisible
+    ) {
+        Set<LocalPosition> strays = new HashSet<>();
+        for (int x = area.minimumX(); x < area.maximumX(); x++) {
+            for (int y = 0; y < variantBounds.dimensions().height(); y++) {
+                for (int z = area.minimumZ(); z < area.maximumZ(); z++) {
+                    Block block = world.getBlockAt(
+                            variantBounds.originX() + x,
+                            variantBounds.originY() + y,
+                            variantBounds.originZ() + z);
+                    if (block.getType() != Material.JIGSAW) {
+                        continue;
+                    }
+                    LocalPosition position = new LocalPosition(x, y, z);
+                    if (!connectorsVisible || !savedConnectors.contains(position)) {
+                        strays.add(position);
+                    }
+                }
+            }
+        }
+        return strays;
+    }
+
     private void completeConnectorRepair(
             Player player,
             ActiveStudio studio,
             int connectorCount,
+            int clearedMarkers,
             String failure,
             Throwable cause
     ) {
         UUID requestId = studio.generator().getRequest().requestId();
-        boolean scheduled = J.runEntity(player, () -> {
+        Runnable release = () -> {
             finishMaterialization(requestId);
             if (cause != null) {
                 IrisLogging.reportError(cause);
             }
+        };
+        boolean scheduled = J.runEntity(player, () -> {
+            release.run();
             if (!failure.isEmpty()) {
                 message(player, "Connector reset was incomplete: " + failure + ". Retry after visiting the workcell.");
                 return;
             }
             message(player, "Restored " + connectorCount
-                    + " connector block(s) from the last saved iteration.");
+                    + " connector block(s) from the last saved iteration"
-        });
+                    + (clearedMarkers == 0 ? "." : " and cleared " + clearedMarkers + " unsaved marker(s)."));
+        }, 0, release);
         if (!scheduled) {
-            finishMaterialization(requestId);
+            release.run();
-            if (cause != null) {
-                IrisLogging.reportError(cause);
-            }
         }
     }
 
@@ -474,6 +569,7 @@ final class JigsawStudioMaterializer {
             try {
                 work.studio().generator().invalidateRender(work.workcell().stableId());
                 work.studio().replacePopulation(work.workcell(), work.target(), "", true);
+                service.floorPainter.refresh(work.studio(), work.workcell().stableId());
                 service.playerContext.refreshWorkcellContext(work.studio().worldId(), work.workcell().stableId());
                 message(work.player(), work.connectorVisibilityChange()
                         ? "Connector blocks are now "
@@ -564,6 +660,7 @@ final class JigsawStudioMaterializer {
                 work.studio().generator().invalidateRender(work.workcell().stableId());
                 if (rollbackFailure.isEmpty() && released) {
                     work.studio().replacePopulation(work.workcell(), work.previous(), "", true);
+                    service.floorPainter.refresh(work.studio(), work.workcell().stableId());
                     service.playerContext.refreshWorkcellContext(work.studio().worldId(), work.workcell().stableId());
                     message(work.player(), candidateFailure + " The previous variant was restored.");
                     return;
@@ -572,6 +669,7 @@ final class JigsawStudioMaterializer {
                         ? "The previous variant could not be restored because the Studio session changed."
                         : rollbackFailure;
                 work.studio().replacePopulation(work.workcell(), work.previous(), failure, false);
+                service.floorPainter.refresh(work.studio(), work.workcell().stableId());
                 service.playerContext.refreshWorkcellContext(work.studio().worldId(), work.workcell().stableId());
                 message(work.player(), candidateFailure + " Automatic rollback also failed: " + failure
                         + " Do not save this workcell until it is reopened.");
@@ -614,6 +712,31 @@ final class JigsawStudioMaterializer {
         }
     }
 
+    enum ConnectorEditStatus {
+        STARTED,
+        BUSY,
+        BLOCKED
+    }
+
+    record ConnectorEditReservation(ConnectorEditStatus status, String message) {
+        ConnectorEditReservation {
+            Objects.requireNonNull(status, "Jigsaw Studio connector edit status");
+            message = message == null ? "" : message;
+        }
+
+        static ConnectorEditReservation started() {
+            return new ConnectorEditReservation(ConnectorEditStatus.STARTED, "");
+        }
+
+        static ConnectorEditReservation busy(String message) {
+            return new ConnectorEditReservation(ConnectorEditStatus.BUSY, message);
+        }
+
+        static ConnectorEditReservation blocked(String message) {
+            return new ConnectorEditReservation(ConnectorEditStatus.BLOCKED, message);
+        }
+    }
+
     public record VariantReloadRequest(
             String workcellId,
             JigsawStudioGenerator.RenderedBay previous

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioMenuController.java

@@ -857,7 +857,7 @@ public final class JigsawStudioMenuController {
         }
         JigsawStudioMenuState.Workcell workcell = current.get().workcell(workcellId);
         JigsawStudioMenuState.Variant target = variant(workcell, pieceKey);
-        if (target == null || !target.owned() || target.active()) {
+        if (!current.get().canDeleteVariant(workcell, target)) {
             stale(player);
             return;
         }

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioMenuState.java

@@ -54,6 +54,20 @@ public record JigsawStudioMenuState(
         }
     }
 
+    public boolean canDeleteVariant(Workcell workcell, Variant variant) {
+        if (workcell == null || variant == null || !variant.owned()) {
+            return false;
+        }
+        if (mode == JigsawStudioMode.SPATIAL_JIGSAW) {
+            int variants = 0;
+            for (Workcell current : workcells) {
+                variants += current.variants().size();
+            }
+            return variants > 1;
+        }
+        return !variant.active() && workcell.variants().size() > 1;
+    }
+
     public Workcell selectedWorkcell() {
         if (selectedWorkcellId.isEmpty()) {
             return null;

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioPlayerContext.java

@@ -59,7 +59,7 @@ final class JigsawStudioPlayerContext {
             return;
         }
         JigsawStudioSession session = studio.generator().getSession();
-        JigsawStudioBay workcell = session.layout().findAt(
+        JigsawStudioBay workcell = session.layout().findColumn(
                 target.getBlockX(), target.getBlockY(), target.getBlockZ());
         boolean owner = ownerMatches(player, studio);
         selectEnteredWorkcell(session, workcell, owner);

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioProjectCreator.java

@@ -36,13 +36,9 @@ import java.util.Objects;
 
 public final class JigsawStudioProjectCreator {
     private static final Gson GSON = new GsonBuilder().setPrettyPrinting().create();
-    private static final List<IrisDirection> SPATIAL_CONNECTOR_ORDER = List.of(
+    private static final int DEFAULT_MAX_DEPTH = 7;
-            IrisDirection.NORTH_NEGATIVE_Z,
+    private static final int SPATIAL_PORTABLE_MAX_DEPTH = 4;
-            IrisDirection.SOUTH_POSITIVE_Z,
+    private static final int SPATIAL_MAXIMUM_PLACEMENTS = 4;
-            IrisDirection.EAST_POSITIVE_X,
-            IrisDirection.WEST_NEGATIVE_X,
-            IrisDirection.UP_POSITIVE_Y,
-            IrisDirection.DOWN_NEGATIVE_Y);
 
     private JigsawStudioProjectCreator() {
     }
@@ -59,7 +55,7 @@ public final class JigsawStudioProjectCreator {
         StructureKey ownershipKey = new StructureKey("iris", resourceKey);
         IrisStructure structure = new IrisStructure()
                 .setStartPool(resourceKey + "/start")
-                .setMaxDepth(7)
+                .setMaxDepth(maxDepth(options))
                 .setMaxSizeChunks(8)
                 .setMode(toModelMode(options.mode()))
                 .setCompatibility(toModelCompatibility(options.compatibilityTarget()))
@@ -94,6 +90,13 @@ public final class JigsawStudioProjectCreator {
         return output.toByteArray();
     }
 
+    private static int maxDepth(Options options) {
+        return options.mode() == JigsawStudioMode.SPATIAL_JIGSAW
+                && options.compatibilityTarget() == JigsawStudioCompatibilityTarget.VANILLA_PORTABLE
+                ? SPATIAL_PORTABLE_MAX_DEPTH
+                : DEFAULT_MAX_DEPTH;
+    }
+
     private static IrisJigsawMode toModelMode(JigsawStudioMode mode) {
         return mode == JigsawStudioMode.PLANAR_JIGSAW
                 ? IrisJigsawMode.PLANAR_JIGSAW
@@ -129,14 +132,11 @@ public final class JigsawStudioProjectCreator {
         IrisJigsawPool piecePool = new IrisJigsawPool().setFallback(capPoolKey);
         IrisJigsawPool capPool = new IrisJigsawPool();
         for (JigsawPlanarArchetype archetype : JigsawPlanarArchetype.values()) {
-            String key = options.structureKey() + "/" + archetype.name().toLowerCase(Locale.ROOT);
+            String key = archetypeKey(options, archetype);
             IrisJigsawPiece piece = planarPiece(key, piecePoolKey, size, archetype);
             if (options.compatibilityTarget() == JigsawStudioCompatibilityTarget.IRIS_EXTENDED) {
                 piece.getThemes().add("variant-1");
             }
-            if (archetype == JigsawPlanarArchetype.CROSS) {
-                pool.getPieces().add(new IrisJigsawPieceEntry(key, 1));
-            }
             if (archetype != JigsawPlanarArchetype.BLANK) {
                 piecePool.getPieces().add(new IrisJigsawPieceEntry(key, 1));
             }
@@ -159,6 +159,8 @@ public final class JigsawStudioProjectCreator {
                     dimensions.depth())));
             bundle.textResource("jigsaw-pieces/" + key + ".json", GSON.toJson(piece) + "\n");
         }
+        pool.getPieces().add(new IrisJigsawPieceEntry(archetypeKey(options, JigsawPlanarArchetype.CROSS), 3));
+        pool.getPieces().add(new IrisJigsawPieceEntry(archetypeKey(options, JigsawPlanarArchetype.BLANK), 1));
         capPool.getPieces().add(new IrisJigsawPieceEntry().setEmpty(true));
         bundle.textResource("jigsaw-pools/" + piecePoolKey + ".json", GSON.toJson(piecePool) + "\n");
         bundle.textResource("jigsaw-pools/" + capPoolKey + ".json", GSON.toJson(capPool) + "\n");
@@ -172,26 +174,25 @@ public final class JigsawStudioProjectCreator {
         JigsawStudioCellDimensions dimensions = options.cellDimensions();
         String piecePoolKey = options.structureKey() + "/pieces";
         IrisJigsawPool piecePool = new IrisJigsawPool();
-        for (int connectorCount = 0; connectorCount <= SPATIAL_CONNECTOR_ORDER.size(); connectorCount++) {
+        boolean irisExtended = options.compatibilityTarget() == JigsawStudioCompatibilityTarget.IRIS_EXTENDED;
-            String key = options.structureKey() + "/"
+        for (SpatialVerticalClass vertical : SpatialVerticalClass.values()) {
-                    + (connectorCount == 0 ? "start" : "connectors-" + connectorCount);
+            for (JigsawPlanarArchetype horizontal : JigsawPlanarArchetype.values()) {
-            IrisJigsawPiece piece = spatialPiece(
+                String key = archetypeKey(options, horizontal) + vertical.keySuffix();
-                    key,
+                IrisJigsawPiece piece = spatialPiece(key, piecePoolKey, dimensions, horizontal, vertical);
-                    piecePoolKey,
+                if (irisExtended) {
-                    dimensions,
+                    piece.getThemes().add("variant-1");
-                    connectorCount);
+                    piece.setRules(new IrisJigsawPieceRules().setMaximumPlacements(SPATIAL_MAXIMUM_PLACEMENTS));
-            if (options.compatibilityTarget() == JigsawStudioCompatibilityTarget.IRIS_EXTENDED) {
+                }
-                piece.getThemes().add("variant-1");
+                pool.getPieces().add(new IrisJigsawPieceEntry(key, 1));
+                if (!piece.getConnectors().isEmpty()) {
+                    piecePool.getPieces().add(new IrisJigsawPieceEntry(key, 1));
+                }
+                bundle.resource("objects/" + key + ".iob", serialize(new IrisObject(
+                        dimensions.width(),
+                        dimensions.height(),
+                        dimensions.depth())));
+                bundle.textResource("jigsaw-pieces/" + key + ".json", GSON.toJson(piece) + "\n");
             }
-            pool.getPieces().add(new IrisJigsawPieceEntry(key, 1));
-            if (connectorCount > 0) {
-                piecePool.getPieces().add(new IrisJigsawPieceEntry(key, 1));
-            }
-            bundle.resource("objects/" + key + ".iob", serialize(new IrisObject(
-                    dimensions.width(),
-                    dimensions.height(),
-                    dimensions.depth())));
-            bundle.textResource("jigsaw-pieces/" + key + ".json", GSON.toJson(piece) + "\n");
         }
         piecePool.getPieces().add(new IrisJigsawPieceEntry().setEmpty(true));
         bundle.textResource("jigsaw-pools/" + piecePoolKey + ".json", GSON.toJson(piecePool) + "\n");
@@ -201,30 +202,40 @@ public final class JigsawStudioProjectCreator {
             String objectKey,
             String poolKey,
             JigsawStudioCellDimensions dimensions,
-            int connectorCount
+            JigsawPlanarArchetype horizontal,
+            SpatialVerticalClass vertical
     ) {
         IrisJigsawPiece piece = new IrisJigsawPiece()
-                .setDisplayName(connectorCount + (connectorCount == 1 ? " Connector" : " Connectors"))
+                .setDisplayName(horizontal.displayName() + vertical.displaySuffix())
                 .setObject(objectKey)
-                .setRotatable(true)
+                .setRotatable(true);
-                .setRules(new IrisJigsawPieceRules().setMaximumPlacements(16));
+        for (JigsawPlanarDirection planarDirection : horizontal.canonicalTopology().directions()) {
-        for (int index = 0; index < connectorCount; index++) {
+            piece.getConnectors().add(spatialConnector(dimensions, planarDirection.irisDirection(), poolKey));
-            IrisDirection direction = SPATIAL_CONNECTOR_ORDER.get(index);
+        }
-            piece.getConnectors().add(new IrisJigsawConnector()
+        for (IrisDirection direction : vertical.directions()) {
-                    .setPosition(spatialConnectorPosition(dimensions, direction))
+            piece.getConnectors().add(spatialConnector(dimensions, direction, poolKey));
-                    .setDirection(direction)
-                    .setTop(direction.isVertical()
-                            ? IrisDirection.NORTH_NEGATIVE_Z
-                            : IrisDirection.UP_POSITIVE_Y)
-                    .setPool(poolKey)
-                    .setName("iris:spatial")
-                    .setTargetName("iris:spatial")
-                    .setJoint(JigsawJoint.ROLLABLE)
-                    .setFinalState("minecraft:structure_void"));
         }
         return piece;
     }
 
+    private static IrisJigsawConnector spatialConnector(
+            JigsawStudioCellDimensions dimensions,
+            IrisDirection direction,
+            String poolKey
+    ) {
+        return new IrisJigsawConnector()
+                .setPosition(spatialConnectorPosition(dimensions, direction))
+                .setDirection(direction)
+                .setTop(direction.isVertical()
+                        ? IrisDirection.NORTH_NEGATIVE_Z
+                        : IrisDirection.UP_POSITIVE_Y)
+                .setPool(poolKey)
+                .setName("iris:spatial")
+                .setTargetName("iris:spatial")
+                .setJoint(JigsawJoint.ROLLABLE)
+                .setFinalState("minecraft:structure_void");
+    }
+
     private static IrisPosition spatialConnectorPosition(
             JigsawStudioCellDimensions dimensions,
             IrisDirection direction
@@ -242,6 +253,10 @@ public final class JigsawStudioProjectCreator {
         };
     }
 
+    private static String archetypeKey(Options options, JigsawPlanarArchetype archetype) {
+        return options.structureKey() + "/" + archetype.name().toLowerCase(Locale.ROOT);
+    }
+
     private static IrisJigsawPiece planarPiece(
             String objectKey,
             String poolKey,
@@ -291,4 +306,33 @@ public final class JigsawStudioProjectCreator {
             return key;
         }
     }
+
+    private enum SpatialVerticalClass {
+        NONE("", "", List.of()),
+        UP("-up", " + Up", List.of(IrisDirection.UP_POSITIVE_Y)),
+        DOWN("-down", " + Down", List.of(IrisDirection.DOWN_NEGATIVE_Y)),
+        UP_DOWN("-up-down", " + Up/Down", List.of(IrisDirection.UP_POSITIVE_Y, IrisDirection.DOWN_NEGATIVE_Y));
+
+        private final String keySuffix;
+        private final String displaySuffix;
+        private final List<IrisDirection> directions;
+
+        SpatialVerticalClass(String keySuffix, String displaySuffix, List<IrisDirection> directions) {
+            this.keySuffix = keySuffix;
+            this.displaySuffix = displaySuffix;
+            this.directions = directions;
+        }
+
+        private String keySuffix() {
+            return keySuffix;
+        }
+
+        private String displaySuffix() {
+            return displaySuffix;
+        }
+
+        private List<IrisDirection> directions() {
+            return directions;
+        }
+    }
 }

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioProtection.java

@@ -128,7 +128,7 @@ final class JigsawStudioProtection {
 
     static boolean blocksMutatingCommand(UUID ownerId, UUID actorId, String commandLine) {
         return !ownerMatches(ownerId, actorId)
-                && !isSafeNonOwnerCommand(commandLine);
+                && isMutatingCommand(commandLine);
     }
 
     static boolean blocksNonEditableWorkcellMutation(
@@ -231,17 +231,25 @@ final class JigsawStudioProtection {
     }
 
     boolean isUnauthorizedStudioEdit(Player player, Block block) {
-        if (player == null || block == null) {
+        String refusal = studioEditRefusal(player, block);
+        if (refusal.isEmpty()) {
             return false;
         }
+        message(player, refusal);
+        return true;
+    }
+
+    String studioEditRefusal(Player player, Block block) {
+        if (player == null || block == null) {
+            return "";
+        }
         ActiveStudio studio = service.studios.get(block.getWorld().getUID());
         if (studio == null) {
-            return false;
+            return "";
         }
         UUID requestId = studio.generator().getRequest().requestId();
         if (service.previewRenderer.contains(requestId, block.getX(), block.getY(), block.getZ())) {
-            message(player, "The seed-1337 Jigsaw preview is read-only and refreshes automatically.");
+            return "The seed-1337 Jigsaw preview is read-only and refreshes automatically.";
-            return true;
         }
         JigsawStudioSession session = studio.generator().getSession();
         JigsawStudioBay bay = session.layout().findAt(block.getX(), block.getY(), block.getZ());
@@ -249,24 +257,20 @@ final class JigsawStudioProtection {
                 ? null
                 : session.activeVariant(bay.stableId()).orElse(null);
         if (bay != null && (variant == null || !variant.owned())) {
-            message(player, variant == null
+            return variant == null
                     ? "This empty Jigsaw Studio workcell has no loaded editable variant. Load one before editing it."
-                    : "This Jigsaw Studio variant is read-only. Adopt or clone its graph before editing it.");
+                    : "This Jigsaw Studio variant is read-only. Adopt or clone its graph before editing it.";
-            return true;
         }
         if (service.saveLifecycle.reopenRequiredRequests.contains(requestId)) {
-            message(player, "Close and reopen Jigsaw Studio before editing the resized layout.");
+            return "Close and reopen Jigsaw Studio before editing the resized layout.";
-            return true;
         }
         if (materializationInProgress(studio)) {
-            message(player, "Wait for the current Jigsaw Studio variant load or rollback to finish.");
+            return "Wait for the current Jigsaw Studio variant load or rollback to finish.";
-            return true;
         }
         if (!blocksStudioEdit(studio.generator().getRequest().ownerId(), player.getUniqueId())) {
-            return false;
+            return "";
         }
-        message(player, "This Jigsaw Studio is owned by another player session.");
+        return "This Jigsaw Studio is owned by another player session.";
-        return true;
     }
 
     boolean materializationInProgress(ActiveStudio studio) {

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioProtectionListener.java

@@ -105,6 +105,7 @@ final class JigsawStudioProtectionListener implements Listener {
         ActiveStudio studio = service.studios.get(event.getWorld().getUID());
         if (studio != null) {
             service.registry.markChunkAvailable(studio, event.getChunk().getX(), event.getChunk().getZ());
+            service.floorPainter.refreshChunk(studio, event.getChunk().getX(), event.getChunk().getZ());
         }
     }
 
@@ -119,6 +120,7 @@ final class JigsawStudioProtectionListener implements Listener {
         service.toolbelt.closeMenu(event.getPlayer());
         service.tileWatcher.finalizeJigsawTileWatchesForPlayer(event.getPlayer().getUniqueId());
         service.tripleSneakTracker.clearPlayer(event.getPlayer().getUniqueId());
+        service.connectorTool.clearPlayer(event.getPlayer().getUniqueId());
         service.visualization.visualizationLoops.remove(event.getPlayer().getUniqueId());
         service.visualization.assemblyPreviews.remove(event.getPlayer().getUniqueId());
         service.playerContext.playerWorkcells.remove(event.getPlayer().getUniqueId());
@@ -133,6 +135,7 @@ final class JigsawStudioProtectionListener implements Listener {
         service.tileWatcher.finalizeJigsawTileWatchesForPlayer(playerId);
         service.tripleSneakTracker.clearPlayer(playerId);
         service.toolbelt.toolConfirmations.remove(playerId);
+        service.connectorTool.clearPlayer(playerId);
         service.visualization.visualizationLoops.remove(playerId);
         service.particlesDisabled.remove(playerId);
         service.visualization.assemblyPreviews.remove(playerId);
@@ -170,15 +173,29 @@ final class JigsawStudioProtectionListener implements Listener {
                 || (event.getClickedBlock() != null && event.useInteractedBlock() == Event.Result.DENY)) {
             return;
         }
-        if (event.getHand() != EquipmentSlot.HAND
+        if (event.getHand() != EquipmentSlot.HAND || event.getAction() == Action.PHYSICAL) {
-                || (event.getAction() != Action.RIGHT_CLICK_AIR
-                && event.getAction() != Action.RIGHT_CLICK_BLOCK)) {
             return;
         }
+        boolean leftClick = event.getAction() == Action.LEFT_CLICK_AIR
+                || event.getAction() == Action.LEFT_CLICK_BLOCK;
         Optional<JigsawStudioToolPayload> decoded = service.toolbelt.toolCodec.decode(event.getItem());
         if (decoded.isEmpty()) {
             return;
         }
+        if (decoded.get().action() == JigsawStudioToolAction.CONNECTOR_TOOL) {
+            service.tileWatcher.finalizeJigsawTileWatchesForPlayer(event.getPlayer().getUniqueId());
+            event.setCancelled(true);
+            service.connectorTool.handleClick(
+                    event.getPlayer(),
+                    decoded.get(),
+                    leftClick,
+                    event.getClickedBlock(),
+                    event.getBlockFace());
+            return;
+        }
+        if (leftClick) {
+            return;
+        }
         service.tileWatcher.finalizeJigsawTileWatchesForPlayer(event.getPlayer().getUniqueId());
         event.setCancelled(true);
         service.toolbelt.useTool(event.getPlayer(), decoded.get(), event.getItem(), event.getPlayer().isSneaking());
@@ -237,6 +254,13 @@ final class JigsawStudioProtectionListener implements Listener {
 
     @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
     public void onProtectedBlockBreak(BlockBreakEvent event) {
+        if (service.studios.containsKey(event.getBlock().getWorld().getUID())
+                && service.toolbelt.toolCodec.decode(event.getPlayer().getInventory().getItemInMainHand())
+                .filter(payload -> payload.action() == JigsawStudioToolAction.CONNECTOR_TOOL)
+                .isPresent()) {
+            event.setCancelled(true);
+            return;
+        }
         if (service.protection.isControlChest(event.getBlock())) {
             event.setCancelled(true);
             message(event.getPlayer(), "The Jigsaw Studio control chest cannot be removed.");
@@ -264,9 +288,17 @@ final class JigsawStudioProtectionListener implements Listener {
 
     @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
     public void onUnauthorizedInteract(PlayerInteractEvent event) {
-        if (event.getAction() == Action.RIGHT_CLICK_BLOCK
+        if (event.getAction() != Action.RIGHT_CLICK_BLOCK
-                && !service.protection.isControlChest(event.getClickedBlock())
+                || service.protection.isControlChest(event.getClickedBlock())) {
-                && service.protection.isUnauthorizedStudioEdit(event.getPlayer(), event.getClickedBlock())) {
+            return;
+        }
+        if (ProtectionProbe.isProbe(event)) {
+            if (!service.protection.studioEditRefusal(event.getPlayer(), event.getClickedBlock()).isEmpty()) {
+                event.setCancelled(true);
+            }
+            return;
+        }
+        if (service.protection.isUnauthorizedStudioEdit(event.getPlayer(), event.getClickedBlock())) {
             event.setCancelled(true);
         }
     }
@@ -337,7 +369,8 @@ final class JigsawStudioProtectionListener implements Listener {
     @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
     public void onProtectedPistonExtend(BlockPistonExtendEvent event) {
         if (service.protection.materializationInProgress(service.studios.get(event.getBlock().getWorld().getUID()))
-                || service.protection.movesProtectedBlocks(event.getBlocks(), event.getDirection())) {
+                || service.protection.movesProtectedBlocks(event.getBlocks(), event.getDirection())
+                || service.protection.isImmutableStudioBlock(event.getBlock().getRelative(event.getDirection()))) {
             event.setCancelled(true);
         }
     }

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioResourceBundleAssembler.java

@@ -129,6 +129,11 @@ final class JigsawStudioResourceBundleAssembler {
         return new Assembly(bundle.build(), objectKey, piece, StructureHash.sha256(manifestContent));
     }
 
+    static byte[] ownedResourceContent(Path packRoot, String relativePath) throws IOException {
+        Path root = Objects.requireNonNull(packRoot, "Jigsaw Studio pack root").toAbsolutePath().normalize();
+        return Files.readAllBytes(resolveOwnedResource(root, relativePath));
+    }
+
     private static Set<String> resourcePaths(StructurePackageClosure closure) {
         Set<String> resources = new LinkedHashSet<>();
         addPaths(resources, "structures", closure.structures(), ".json");

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioSaveLifecycle.java

@@ -286,7 +286,7 @@ final class JigsawStudioSaveLifecycle {
         String selected = session.selectedBayId().orElse(null);
         if (selected == null) {
             Location location = player.getLocation();
-            JigsawStudioBay underPlayer = session.layout().findAt(
+            JigsawStudioBay underPlayer = session.layout().findColumn(
                     location.getBlockX(), location.getBlockY(), location.getBlockZ());
             if (underPlayer != null) {
                 selected = underPlayer.stableId();

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioService.java

@@ -73,6 +73,8 @@ public final class JigsawStudioService implements IrisService, JigsawStudioMenuA
     final JigsawStudioAutosaveScheduler autosaveScheduler = new JigsawStudioAutosaveScheduler(this);
     final JigsawStudioTileWatcher tileWatcher = new JigsawStudioTileWatcher(this);
     final JigsawStudioVisualization visualization = new JigsawStudioVisualization(this);
+    final JigsawStudioFloorPainter floorPainter = new JigsawStudioFloorPainter(this);
+    final JigsawStudioConnectorTool connectorTool = new JigsawStudioConnectorTool(this);
     final JigsawStudioPlayerContext playerContext = new JigsawStudioPlayerContext(this);
 
     public static JigsawStudioService get() {

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioToolAction.java

@@ -4,6 +4,7 @@ import java.util.Objects;
 
 public enum JigsawStudioToolAction {
     OPEN_MENU("Open Control Menu", false),
+    CONNECTOR_TOOL("Connector Tool", false),
     SELECT_WORKCELL("Select Workcell", false),
     TOGGLE_WORKCELL("Toggle Workcell", false),
     LOAD_VARIANT("Load Variant", false),

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioToolCodec.java

@@ -140,6 +140,13 @@ public final class JigsawStudioToolCodec {
         if (payload.amount() != 0) {
             lore.add(ChatColor.GRAY + "Amount: " + payload.amount());
         }
+        if (payload.action() == JigsawStudioToolAction.CONNECTOR_TOOL) {
+            lore.add(ChatColor.YELLOW + "Right-click: place, select, or move a connector");
+            lore.add(ChatColor.YELLOW + "Left-click: remove a connector");
+            lore.add(ChatColor.GRAY + "Faces out of the clicked face; sneak to face into it");
+            lore.add(ChatColor.GRAY + "Planar: right-click a side to seat its socket");
+            return List.copyOf(lore);
+        }
         lore.add(payload.action().destructive()
                 ? ChatColor.RED + "Right-click twice to confirm"
                 : ChatColor.YELLOW + "Right-click to use");

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioToolbelt.java

@@ -29,6 +29,7 @@ import static art.arcane.iris.studio.jigsaw.JigsawStudioVariantProperties.canRes
 
 final class JigsawStudioToolbelt {
     private static final long TOOL_CONFIRM_NANOS = 10_000_000_000L;
+    private static final long TOOL_CONFIRM_MINIMUM_NANOS = 500_000_000L;
 
     private final JigsawStudioService service;
     final Map<UUID, DeferredDuplication> deferredDuplications = new ConcurrentHashMap<>();
@@ -184,13 +185,27 @@ final class JigsawStudioToolbelt {
             message(player, "This Jigsaw Studio tool is stale or belongs to another session.");
             return false;
         }
-        if (payload.action().destructive() && !confirmTool(player, payload)) {
+        if (payload.action().destructive()) {
-            message(player, "Right-click the same tool again within 10 seconds to confirm "
+            ToolConfirmationState confirmation = confirmTool(player, payload);
-                    + payload.action().displayName() + ".");
+            if (confirmation == ToolConfirmationState.ARMED) {
-            return true;
+                message(player, "Right-click the same tool again within 10 seconds to confirm "
+                        + payload.action().displayName() + ".");
+                return true;
+            }
+            if (confirmation == ToolConfirmationState.HELD) {
+                return true;
+            }
+        }
+        if (requiresBoundVariant(payload) && activeOwnedVariant(
+                player,
+                studio,
+                payload.workcellId(),
+                payload.pieceKey()) == null) {
+            return false;
         }
         return switch (payload.action()) {
             case OPEN_MENU -> openControlMenu(player);
+            case CONNECTOR_TOOL -> service.connectorTool.handleClick(player, payload, false, null, null);
             case SELECT_WORKCELL -> selectWorkcell(player, payload.workcellId());
             case LOAD_VARIANT -> service.variantEditor.switchVariant(
                     player,
@@ -349,19 +364,40 @@ final class JigsawStudioToolbelt {
         return state.isPresent() && service.workcellEditor.setRequireCaps(player, !state.get().requireCaps());
     }
 
-    private boolean confirmTool(Player player, JigsawStudioToolPayload payload) {
+    private ToolConfirmationState confirmTool(Player player, JigsawStudioToolPayload payload) {
         long now = System.nanoTime();
         ToolConfirmation previous = toolConfirmations.get(player.getUniqueId());
-        if (previous != null
+        ToolConfirmationState state = confirmationState(previous, payload, now);
-                && previous.expiresAtNanos() >= now
+        if (state == ToolConfirmationState.CONFIRMED) {
-                && previous.payload().equals(payload)) {
             toolConfirmations.remove(player.getUniqueId(), previous);
-            return true;
+        } else if (state == ToolConfirmationState.ARMED) {
+            toolConfirmations.put(
+                    player.getUniqueId(),
+                    new ToolConfirmation(payload, now, now + TOOL_CONFIRM_NANOS));
         }
-        toolConfirmations.put(
+        return state;
-                player.getUniqueId(),
+    }
-                new ToolConfirmation(payload, now + TOOL_CONFIRM_NANOS));
+
-        return false;
+    static ToolConfirmationState confirmationState(
+            ToolConfirmation previous,
+            JigsawStudioToolPayload payload,
+            long nowNanos
+    ) {
+        if (previous == null
+                || previous.expiresAtNanos() < nowNanos
+                || !previous.payload().equals(payload)) {
+            return ToolConfirmationState.ARMED;
+        }
+        return nowNanos - previous.armedAtNanos() < TOOL_CONFIRM_MINIMUM_NANOS
+                ? ToolConfirmationState.HELD
+                : ToolConfirmationState.CONFIRMED;
+    }
+
+    static boolean requiresBoundVariant(JigsawStudioToolPayload payload) {
+        return !payload.pieceKey().isEmpty() && switch (payload.action()) {
+            case DUPLICATE_VARIANT, TOGGLE_ROTATION, EXPAND_TO_CELL -> true;
+            default -> false;
+        };
     }
 
     JigsawStudioVariant activeOwnedVariant(
@@ -677,7 +713,13 @@ final class JigsawStudioToolbelt {
         }
     }
 
-    record ToolConfirmation(JigsawStudioToolPayload payload, long expiresAtNanos) {
+    enum ToolConfirmationState {
+        ARMED,
+        HELD,
+        CONFIRMED
+    }
+
+    record ToolConfirmation(JigsawStudioToolPayload payload, long armedAtNanos, long expiresAtNanos) {
         ToolConfirmation {
             Objects.requireNonNull(payload, "Jigsaw Studio tool confirmation payload");
         }

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioToolboxMenu.java

@@ -105,6 +105,9 @@ final class JigsawStudioToolboxMenu {
                 "Jigsaw Studio toolbox workcell");
         UUID requestId = menu.requestId();
         List<ToolboxTool> tools = new ArrayList<>();
+        tools.add(new ToolboxTool(
+                "Connector Tool",
+                JigsawStudioToolPayload.request(JigsawStudioToolAction.CONNECTOR_TOOL, requestId)));
         tools.add(new ToolboxTool(
                 "Open Control Menu",
                 JigsawStudioToolPayload.request(JigsawStudioToolAction.OPEN_MENU, requestId)));
@@ -216,6 +219,15 @@ final class JigsawStudioToolboxMenu {
                                 selected.stableId(),
                                 active.pieceKey())));
             }
+            if (menu.mode() == JigsawStudioMode.SPATIAL_JIGSAW && menu.canDeleteVariant(selected, active)) {
+                tools.add(new ToolboxTool(
+                        "Delete " + active.displayName(),
+                        JigsawStudioToolPayload.variant(
+                                JigsawStudioToolAction.DELETE_VARIANT,
+                                requestId,
+                                selected.stableId(),
+                                active.pieceKey())));
+            }
             if (active.owned()) {
                 for (JigsawStudioMenuState.Membership membership : active.memberships()) {
                     addMembershipTools(
@@ -255,7 +267,7 @@ final class JigsawStudioToolboxMenu {
                                 selected.stableId(),
                                 variant.pieceKey())));
             }
-            if (variant.owned() && selected.variants().size() > 1) {
+            if (menu.canDeleteVariant(selected, variant)) {
                 tools.add(new ToolboxTool(
                         "Delete " + variant.displayName(),
                         JigsawStudioToolPayload.variant(

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioVariantProperties.java

@@ -174,12 +174,20 @@ final class JigsawStudioVariantProperties {
             return false;
         }
         JigsawStudioSession session = studio.generator().getSession();
+        boolean rotatable = !variant.rotatable();
+        if (variant.dimensions().isPresent()) {
+            String footprintFailure = spatialFootprintFailure(studio, variant,
+                    new JigsawStudioGraphMapper.SpatialChange(variant.pieceKey(), variant.dimensions().get(), rotatable));
+            if (!footprintFailure.isEmpty()) {
+                message(player, footprintFailure);
+                return false;
+            }
+        }
         String reservationFailure = service.graphMutations.beginGraphMutation(studio, session);
         if (!reservationFailure.isEmpty()) {
             message(player, reservationFailure);
             return false;
         }
-        boolean rotatable = !variant.rotatable();
         return service.graphMutations.scheduleGraphMutation(
                 player,
                 studio,
@@ -268,6 +276,12 @@ final class JigsawStudioVariantProperties {
                     + dimensions.width() + "x" + dimensions.height() + "x" + dimensions.depth() + ".");
             return false;
         }
+        String footprintFailure = spatialFootprintFailure(studio, variant,
+                new JigsawStudioGraphMapper.SpatialChange(variant.pieceKey(), dimensions, variant.rotatable()));
+        if (!footprintFailure.isEmpty()) {
+            message(player, footprintFailure);
+            return false;
+        }
         boolean active = session.activeVariant(workcellId)
                 .map(activeVariant -> activeVariant.pieceKey().equals(pieceKey))
                 .orElse(false);
@@ -536,4 +550,23 @@ final class JigsawStudioVariantProperties {
                 || canonical.height() < target.height()
                 || canonical.depth() < target.depth());
     }
+
+    private static String spatialFootprintFailure(
+            ActiveStudio studio,
+            JigsawStudioVariant variant,
+            JigsawStudioGraphMapper.SpatialChange change
+    ) {
+        if (variant.mode() != JigsawStudioMode.SPATIAL_JIGSAW) {
+            return "";
+        }
+        IrisStructure structure = loadStudioStructure(studio);
+        if (structure == null) {
+            return "The structure could not be loaded to check the spatial workcell size.";
+        }
+        return JigsawStudioGraphMapper.spatialFootprintFailure(
+                studio.generator().getRequest().source(),
+                JigsawStudioGraphMapper.configuredCellDimensions(structure),
+                studio.generator().getSession().layout().variantCatalog(),
+                change);
+    }
 }

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioVisualization.java

@@ -17,6 +17,7 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
@@ -35,6 +36,9 @@ final class JigsawStudioVisualization {
     private static final Color VALID_CONNECTOR_COLOR = Color.LIME;
     private static final Color ASSEMBLY_PREVIEW_COLOR = Color.fromRGB(180, 90, 255);
     private static final Color LIVE_PREVIEW_WARNING_COLOR = Color.fromRGB(255, 180, 55);
+    private static final Color TOOL_SELECTED_COLOR = Color.YELLOW;
+    private static final Color TOOL_PLACE_COLOR = Color.WHITE;
+    private static final Color TOOL_EXISTING_COLOR = Color.ORANGE;
     private static final long ASSEMBLY_PREVIEW_MILLIS = 10_000L;
 
     private final JigsawStudioService service;
@@ -124,7 +128,7 @@ final class JigsawStudioVisualization {
         JigsawStudioSession session = studio.generator().getSession();
         JigsawStudioLayout layout = session.layout();
         Location playerLocation = player.getLocation();
-        JigsawStudioBay focused = layout.findAt(
+        JigsawStudioBay focused = layout.findColumn(
                 playerLocation.getBlockX(),
                 playerLocation.getBlockY(),
                 playerLocation.getBlockZ());
@@ -134,6 +138,7 @@ final class JigsawStudioVisualization {
             drawConnectors(player, playerLocation, studio, focused, budget);
             drawBounds(player, playerLocation, focused.bounds(), focusedColor, 1.15F, 1.0D, budget);
         }
+        drawConnectorToolFeedback(player, playerLocation, studio, budget);
         drawLivePreview(player, playerLocation, studio, budget);
         drawAssemblyPreview(player, playerLocation, budget);
         for (JigsawStudioBay bay : layout.bays()) {
@@ -148,6 +153,57 @@ final class JigsawStudioVisualization {
         }
     }
 
+    private void drawConnectorToolFeedback(
+            Player player,
+            Location playerLocation,
+            ActiveStudio studio,
+            ParticleBudget budget
+    ) {
+        UUID requestId = studio.generator().getRequest().requestId();
+        boolean holdingTool = service.toolbelt.toolCodec.decode(player.getInventory().getItemInMainHand())
+                .filter(payload -> payload.action() == JigsawStudioToolAction.CONNECTOR_TOOL
+                        && payload.requestId().equals(requestId))
+                .isPresent();
+        Optional<JigsawStudioConnectorTool.Feedback> feedback =
+                service.connectorTool.feedback(player, studio, holdingTool);
+        if (feedback.isEmpty()) {
+            return;
+        }
+        feedback.get().selected().ifPresent(cell ->
+                drawCell(player, playerLocation, cell, TOOL_SELECTED_COLOR, budget));
+        feedback.get().hover().ifPresent(hover -> {
+            Color color = hover.existingConnector() ? TOOL_EXISTING_COLOR : TOOL_PLACE_COLOR;
+            drawCell(player, playerLocation, hover.cell(), color, budget);
+            drawConnectorLine(
+                    player,
+                    playerLocation,
+                    hover.cell().x() + 0.5D,
+                    hover.cell().y() + 0.5D,
+                    hover.cell().z() + 0.5D,
+                    hover.facing(),
+                    color,
+                    budget);
+        });
+    }
+
+    private static void drawCell(
+            Player player,
+            Location playerLocation,
+            JigsawStudioConnectorPlacement.Cell cell,
+            Color color,
+            ParticleBudget budget
+    ) {
+        drawBounds(
+                player,
+                playerLocation,
+                new JigsawStudioPreviewRenderer.PreviewBounds(
+                        cell.x(), cell.y(), cell.z(), cell.x(), cell.y(), cell.z()),
+                color,
+                0.75F,
+                0.25D,
+                budget);
+    }
+
     private void drawLivePreview(
             Player player,
             Location playerLocation,

core/src/main/java/art/arcane/iris/studio/jigsaw/JigsawStudioWorkcellEditor.java

@@ -114,10 +114,6 @@ final class JigsawStudioWorkcellEditor {
             message(player, "Connector blocks cannot reset: " + validationFailure);
             return false;
         }
-        if (rendered.connectors().isEmpty()) {
-            message(player, "The active variant has no saved connectors to reset.");
-            return false;
-        }
         String reservationFailure = service.materializer.beginConnectorRepair(studio);
         if (!reservationFailure.isEmpty()) {
             message(player, reservationFailure);
@@ -125,7 +121,7 @@ final class JigsawStudioWorkcellEditor {
         }
         boolean connectorsVisible = session.workcellSnapshot(workcellId).connectorsVisible();
         message(player, "Resetting " + rendered.connectors().size()
-                + " connector block(s) from the last saved iteration...");
+                + " connector block(s) from the last saved iteration and clearing unsaved markers...");
         return service.materializer.scheduleConnectorRepair(
                 player,
                 studio,
@@ -383,6 +379,16 @@ final class JigsawStudioWorkcellEditor {
             message(player, "Unknown Jigsaw Studio workcell '" + workcellId + "'.");
             return false;
         }
+        JigsawStudioVariant spatialVariant = workcell.archetype().isPresent()
+                ? null
+                : session.activeVariant(workcellId).orElse(null);
+        if (spatialVariant != null) {
+            return service.variantProperties.updateVariantDisplayName(
+                    player,
+                    workcellId,
+                    spatialVariant.pieceKey(),
+                    displayName);
+        }
         String normalizedName;
         try {
             normalizedName = JigsawStudioGraphEditor.normalizeDisplayName(displayName);

core/src/test/java/art/arcane/iris/pack/schema/SchemaBuilderIdentityTest.java

@@ -83,7 +83,7 @@ public class SchemaBuilderIdentityTest {
     @ClassRule
     public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
 
-    private static final String EXPECTED_SCHEMA_DIGEST = "6935e8d3914e5cde852522151d87fe898f79de3b394826e544c5c5bfbfceba57";
+    private static final String EXPECTED_SCHEMA_DIGEST = "b8dd16d1a3188e8150a68a9d5b2964aed5094d679c0f941e3703aec675f87e20";
 
     private static final List<Class<?>> SCHEMA_ROOTS = List.of(
             IrisDimension.class,

core/src/test/java/art/arcane/iris/structure/export/VanillaJigsawDatapackExporterTest.java

@@ -167,6 +167,33 @@ public class VanillaJigsawDatapackExporterTest {
         }
     }
 
+    @Test
+    public void exports1211WithRuntimeDefaultSettingsDerivedFromTheStructure() throws Exception {
+        when(IrisPlatforms.get().minecraftVersion()).thenReturn("1.21.1");
+        try {
+            TestGraph graph = connectorGraph();
+            VanillaJigsawExportResult staticDefaults = new VanillaJigsawDatapackExporter().export(
+                    request(graph, temporaryFolder.getRoot().toPath().resolve("static-defaults-1211"))
+                            .settings(VanillaJigsawExportSettings.defaults()).build());
+            assertTrue(hasCode(staticDefaults, VanillaJigsawExportDiagnostic.Code.INVALID_MAX_DISTANCE));
+
+            Path output = temporaryFolder.getRoot().toPath().resolve("runtime-defaults-1211");
+            VanillaJigsawExportSettings settings = VanillaJigsawExportSettings.runtimeDefaults(graph.structure);
+            VanillaJigsawExportResult result = new VanillaJigsawDatapackExporter().export(
+                    request(graph, output).namespace("studio").resourcePath("village/test").settings(settings).build());
+
+            assertEquals(graph.structure.getMaxSizeChunks() * 16, settings.maxDistanceVertical());
+            assertTrue(result.diagnostics().toString(), result.isSuccess());
+            JsonObject structure = json(output.resolve("data/studio/worldgen/structure/village/test.json"));
+            assertEquals(graph.structure.getMaxSizeChunks() * 16,
+                    structure.get("max_distance_from_center").getAsInt());
+        } finally {
+            when(IrisPlatforms.get().minecraftVersion()).thenReturn("26.2");
+        }
+        assertEquals(VanillaJigsawExportSettings.defaults().maxDistanceVertical(),
+                VanillaJigsawExportSettings.runtimeDefaults(connectorGraph().structure).maxDistanceVertical());
+    }
+
     @Test
     public void rejects1211VanillaExportWithDifferentVerticalDistance() throws Exception {
         when(IrisPlatforms.get().minecraftVersion()).thenReturn("1.21.1");

core/src/test/java/art/arcane/iris/structure/placement/StructureAssemblerTest.java

@@ -38,7 +38,10 @@ import art.arcane.volmlib.util.math.RNG;
 import org.junit.ClassRule;
 import org.junit.Test;
 
+import java.util.EnumSet;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -310,6 +313,82 @@ public class StructureAssemblerTest {
         assertEquals(west.getMaxX() + 1, start.getMinX());
     }
 
+    @Test
+    public void rotatableCandidatesAttachThroughEitherCornerConnectorAcrossSeeds() {
+        Fixture fixture = new Fixture();
+        IrisJigsawPiece startPiece = piece("start-object", false,
+                connector(IrisDirection.NORTH_NEGATIVE_Z, "turns", "door", "door")
+                        .setPosition(new IrisPosition(1, 0, 0))
+                        .setJoint(JigsawJoint.ALIGNED));
+        IrisJigsawPiece cornerPiece = piece("corner-object", true,
+                connector(IrisDirection.NORTH_NEGATIVE_Z, "", "door", "door")
+                        .setPosition(new IrisPosition(1, 0, 0))
+                        .setJoint(JigsawJoint.ALIGNED),
+                connector(IrisDirection.EAST_POSITIVE_X, "", "door", "door")
+                        .setPosition(new IrisPosition(2, 0, 1))
+                        .setJoint(JigsawJoint.ALIGNED));
+        fixture.pool("start", pool("", "start-piece"));
+        fixture.pool("turns", pool("", "corner-piece"));
+        fixture.piece("start-piece", startPiece);
+        fixture.piece("corner-piece", cornerPiece);
+        fixture.object("start-object", new IrisObject(3, 1, 3));
+        fixture.object("corner-object", new IrisObject(3, 1, 3));
+        StructureAssembler assembler = fixture.assembler(structure("start", 1), 0, 0, 0);
+
+        Set<Integer> attachedConnectors = new HashSet<>();
+        for (long seed = 0; seed < 64; seed++) {
+            PlacedStructurePiece corner = requirePlacedPiece(completedPieces(assembler, new RNG(seed)), cornerPiece);
+            for (int index = 0; index < cornerPiece.getConnectors().size(); index++) {
+                if (corner.getRotation().rotate(cornerPiece.getConnectors().get(index).getDirection())
+                        == IrisDirection.SOUTH_POSITIVE_Z) {
+                    attachedConnectors.add(index);
+                }
+            }
+        }
+
+        assertEquals(Set.of(0, 1), attachedConnectors);
+    }
+
+    @Test
+    public void planarJunctionPlacesAPieceOpenTowardEveryOccupiedNeighbor() {
+        Fixture fixture = planarJunctionFixture("straight-piece", "corner-piece");
+        IrisJigsawPiece corner = planarPiece(true,
+                IrisDirection.NORTH_NEGATIVE_Z, IrisDirection.EAST_POSITIVE_X);
+        fixture.piece("straight-piece", planarPiece(true,
+                IrisDirection.NORTH_NEGATIVE_Z, IrisDirection.SOUTH_POSITIVE_Z));
+        fixture.piece("corner-piece", corner);
+        StructureAssembler assembler = fixture.assembler(planarJunctionStructure(), 0, 64, 0);
+
+        for (long seed = 0; seed < 32; seed++) {
+            List<PlacedStructurePiece> placed = completedPieces(assembler, new RNG(seed));
+            PlacedStructurePiece junction = placed.get(3);
+
+            assertEquals(4, placed.size());
+            assertSame("seed " + seed, corner, junction.getPiece());
+            assertEquals("seed " + seed,
+                    Set.of(IrisDirection.WEST_NEGATIVE_X, IrisDirection.SOUTH_POSITIVE_Z),
+                    worldFacings(junction));
+        }
+    }
+
+    @Test
+    public void planarJunctionWithoutAFittingPieceKeepsTheAttachmentOnlyPlacementInsteadOfFailing() {
+        Fixture fixture = planarJunctionFixture("straight-piece");
+        IrisJigsawPiece straight = planarPiece(true,
+                IrisDirection.NORTH_NEGATIVE_Z, IrisDirection.SOUTH_POSITIVE_Z);
+        fixture.piece("straight-piece", straight);
+        StructureAssembler assembler = fixture.assembler(planarJunctionStructure(), 0, 64, 0);
+
+        for (long seed = 0; seed < 8; seed++) {
+            List<PlacedStructurePiece> placed = completedPieces(assembler, new RNG(seed));
+
+            assertEquals(4, placed.size());
+            assertSame(straight, placed.get(3).getPiece());
+            assertEquals(Set.of(IrisDirection.WEST_NEGATIVE_X, IrisDirection.EAST_POSITIVE_X),
+                    worldFacings(placed.get(3)));
+        }
+    }
+
     @Test
     public void selectionPriorityProcessesHigherConnectorsFirstAndPreservesStableTies() {
         Fixture fixture = new Fixture();
@@ -1115,6 +1194,53 @@ public class StructureAssemblerTest {
         return fixture.assembler(structure("start", 1), 0, 0, 0).assemble(new RNG(137L));
     }
 
+    private static Fixture planarJunctionFixture(String... junctionPieces) {
+        Fixture fixture = new Fixture();
+        fixture.pool("start", pool("", "start-piece"));
+        fixture.pool("north", pool("", "north-elbow"));
+        fixture.pool("east", pool("", "east-elbow"));
+        fixture.pool("junction", pool("", junctionPieces));
+        fixture.piece("start-piece", piece("cell-object", false,
+                planarConnector(IrisDirection.NORTH_NEGATIVE_Z, "north"),
+                planarConnector(IrisDirection.EAST_POSITIVE_X, "east")));
+        fixture.piece("north-elbow", piece("cell-object", false,
+                planarConnector(IrisDirection.SOUTH_POSITIVE_Z, ""),
+                planarConnector(IrisDirection.EAST_POSITIVE_X, "junction")));
+        fixture.piece("east-elbow", piece("cell-object", false,
+                planarConnector(IrisDirection.WEST_NEGATIVE_X, ""),
+                planarConnector(IrisDirection.NORTH_NEGATIVE_Z, "")));
+        fixture.object("cell-object", new IrisObject(3, 1, 3));
+        return fixture;
+    }
+
+    private static IrisJigsawPiece planarPiece(boolean rotatable, IrisDirection... directions) {
+        IrisJigsawPiece piece = new IrisJigsawPiece().setObject("cell-object").setRotatable(rotatable);
+        for (IrisDirection direction : directions) {
+            piece.getConnectors().add(planarConnector(direction, ""));
+        }
+        return piece;
+    }
+
+    private static IrisJigsawConnector planarConnector(IrisDirection direction, String pool) {
+        return connector(direction, pool, "door", "door")
+                .setPosition(IrisJigsawConnector.canonicalPlanarPosition(new IrisPosition(3, 1, 3), direction))
+                .setJoint(JigsawJoint.ALIGNED);
+    }
+
+    private static IrisStructure planarJunctionStructure() {
+        return structure("start", 3)
+                .setMode(IrisJigsawMode.PLANAR_JIGSAW)
+                .setCellSize(new IrisPosition(3, 1, 3));
+    }
+
+    private static Set<IrisDirection> worldFacings(PlacedStructurePiece piece) {
+        Set<IrisDirection> facings = EnumSet.noneOf(IrisDirection.class);
+        for (IrisJigsawConnector connector : piece.getPiece().getConnectors()) {
+            facings.add(piece.getRotation().rotate(connector.getDirection()));
+        }
+        return facings;
+    }
+
     private static IrisStructure structure(String startPool, int maxDepth) {
         return new IrisStructure().setStartPool(startPool).setMaxDepth(maxDepth).setMaxSizeChunks(8);
     }

core/src/test/java/art/arcane/iris/studio/generation/JigsawStudioGeneratorTest.java

@@ -2,8 +2,6 @@ package art.arcane.iris.studio.generation;
 
 import art.arcane.iris.pack.loading.IrisData;
 import art.arcane.iris.pack.loading.ResourceLoader;
-import art.arcane.iris.studio.jigsaw.JigsawPlanarArchetype;
-import art.arcane.iris.studio.jigsaw.JigsawPlanarDirection;
 import art.arcane.iris.studio.jigsaw.JigsawPlanarTopology;
 import art.arcane.iris.studio.jigsaw.JigsawStudioActivation;
 import art.arcane.iris.studio.jigsaw.JigsawStudioBay;
@@ -52,6 +50,7 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.mockStatic;
@@ -168,57 +167,123 @@ public class JigsawStudioGeneratorTest {
     }
 
     @Test
-    public void paintsCanonicalWoolGlyphsBelowCaptureAndOneControlChest() {
+    @SuppressWarnings("unchecked")
+    public void paintsActiveVariantConnectorLinesBelowCaptureAndOneControlChest() {
+        IrisData source = mock(IrisData.class);
+        ResourceLoader<IrisJigsawPiece> pieceLoader = mock(ResourceLoader.class);
+        ResourceLoader<IrisObject> objectLoader = mock(ResourceLoader.class);
+        when(source.getJigsawPieceLoader()).thenReturn(pieceLoader);
+        when(source.getObjectLoader()).thenReturn(objectLoader);
         JigsawStudioCellDimensions dimensions = new JigsawStudioCellDimensions(7, 5, 7);
+        IrisJigsawPiece piece = new IrisJigsawPiece()
+                .setObject("village/corner")
+                .setConnectors(new KList<>());
+        piece.getConnectors().add(connector(new IrisPosition(3, 2, 0), IrisDirection.NORTH_NEGATIVE_Z));
+        piece.getConnectors().add(connector(new IrisPosition(6, 2, 3), IrisDirection.EAST_POSITIVE_X));
+        when(pieceLoader.load("village/corner", false)).thenReturn(piece);
+        when(objectLoader.load("village/corner", false)).thenReturn(new IrisObject(7, 5, 7));
+        JigsawStudioVariant variant = planarVariant("village/corner", JigsawPlanarTopology.NORTH_EAST_CORNER);
         GeneratorFixture fixture = fixture(
+                source,
                 JigsawStudioMode.PLANAR_JIGSAW,
                 dimensions,
-                JigsawStudioVariantCatalog.empty());
+                new JigsawStudioVariantCatalog(List.of(variant)));
         JigsawStudioBay corner = fixture.layout().get("workcell/corner");
-        int glyphY = corner.bounds().originY() - 1;
+        int floorY = corner.bounds().originY() - 1;
         int centerX = dimensions.width() / 2;
         int centerZ = dimensions.depth() / 2;
 
-        assertSame(fixture.connectorCap(), stateAt(
+        try (MockedStatic<B> ignored = mockStatic(B.class)) {
-                fixture.generator(),
+            assertSame(fixture.palette().horizontalSocket(), stateAt(
-                corner.bounds().originX() + centerX,
+                    fixture.generator(), corner.bounds().originX() + centerX, floorY, corner.bounds().originZ()));
-                glyphY,
+            assertSame(fixture.palette().horizontalSocket(), stateAt(
-                corner.bounds().originZ()));
+                    fixture.generator(), corner.bounds().maxX(), floorY, corner.bounds().originZ() + centerZ));
-        assertSame(fixture.connectorCap(), stateAt(
+            assertSame(fixture.palette().line(), stateAt(
-                fixture.generator(),
+                    fixture.generator(), corner.bounds().originX() + centerX, floorY, corner.bounds().originZ() + 1));
-                corner.bounds().maxX(),
+            assertSame(fixture.palette().line(), stateAt(
-                glyphY,
+                    fixture.generator(),
-                corner.bounds().originZ() + centerZ));
+                    corner.bounds().originX() + centerX + 1,
-        assertSame(fixture.topologyPath(), stateAt(
+                    floorY,
-                fixture.generator(),
+                    corner.bounds().originZ() + centerZ));
-                corner.bounds().originX() + centerX,
+            assertSame(fixture.palette().base(), stateAt(
-                glyphY,
+                    fixture.generator(), corner.bounds().originX(), floorY, corner.bounds().originZ()));
-                corner.bounds().originZ() + 1));
+            assertFalse(fixture.palette().base() == stateAt(
-        assertSame(fixture.topologyPath(), stateAt(
+                    fixture.generator(),
-                fixture.generator(),
+                    corner.bounds().originX() + centerX,
-                corner.bounds().originX() + centerX + 1,
+                    corner.bounds().originY(),
-                glyphY,
+                    corner.bounds().originZ() + centerZ));
-                corner.bounds().originZ() + centerZ));
-        assertSame(fixture.topologyBase(), stateAt(
-                fixture.generator(),
-                corner.bounds().originX(),
-                glyphY,
-                corner.bounds().originZ()));
-        assertFalse(fixture.topologyBase() == stateAt(
-                fixture.generator(),
-                corner.bounds().originX() + centerX,
-                corner.bounds().originY(),
-                corner.bounds().originZ() + centerZ));
 
-        JigsawStudioBay blank = fixture.layout().get("workcell/blank");
+            JigsawStudioBay blank = fixture.layout().get("workcell/blank");
-        assertSame(fixture.topologyBase(), stateAt(
+            assertSame(fixture.palette().base(), stateAt(
-                fixture.generator(),
+                    fixture.generator(),
-                blank.bounds().originX() + centerX,
+                    blank.bounds().originX() + centerX,
-                blank.bounds().originY() - 1,
+                    blank.bounds().originY() - 1,
-                blank.bounds().originZ() + centerZ));
+                    blank.bounds().originZ() + centerZ));
-        JigsawStudioControlPosition control = fixture.layout().controlPosition();
+            JigsawStudioBay tee = fixture.layout().get("workcell/tee");
-        assertSame(fixture.controlChest(), stateAt(
+            assertSame(fixture.palette().base(), stateAt(
-                fixture.generator(), control.worldX(), control.worldY(), control.worldZ()));
+                    fixture.generator(),
+                    tee.bounds().originX() + centerX,
+                    tee.bounds().originY() - 1,
+                    tee.bounds().originZ()));
+            JigsawStudioControlPosition control = fixture.layout().controlPosition();
+            assertSame(fixture.controlChest(), stateAt(
+                    fixture.generator(), control.worldX(), control.worldY(), control.worldZ()));
+        }
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void spatialWorkcellsPaintVerticalSocketsUnderTheirConnectorColumns() {
+        IrisData source = mock(IrisData.class);
+        ResourceLoader<IrisJigsawPiece> pieceLoader = mock(ResourceLoader.class);
+        ResourceLoader<IrisObject> objectLoader = mock(ResourceLoader.class);
+        when(source.getJigsawPieceLoader()).thenReturn(pieceLoader);
+        when(source.getObjectLoader()).thenReturn(objectLoader);
+        IrisJigsawPiece piece = new IrisJigsawPiece()
+                .setObject("stronghold/shaft")
+                .setConnectors(new KList<>());
+        piece.getConnectors().add(connector(new IrisPosition(2, 4, 2), IrisDirection.UP_POSITIVE_Y)
+                .setTop(IrisDirection.NORTH_NEGATIVE_Z));
+        piece.getConnectors().add(connector(new IrisPosition(2, 0, 2), IrisDirection.DOWN_NEGATIVE_Y)
+                .setTop(IrisDirection.NORTH_NEGATIVE_Z));
+        piece.getConnectors().add(connector(new IrisPosition(0, 1, 4), IrisDirection.DOWN_NEGATIVE_Y)
+                .setTop(IrisDirection.NORTH_NEGATIVE_Z));
+        piece.getConnectors().add(connector(new IrisPosition(2, 2, 0), IrisDirection.NORTH_NEGATIVE_Z));
+        when(pieceLoader.load("stronghold/shaft", false)).thenReturn(piece);
+        when(objectLoader.load("stronghold/shaft", false)).thenReturn(new IrisObject(5, 5, 5));
+        JigsawStudioVariant variant = new JigsawStudioVariant(
+                "stronghold/shaft",
+                "stronghold/shaft",
+                "",
+                Optional.of(new JigsawStudioCellDimensions(5, 5, 5)),
+                JigsawStudioMode.SPATIAL_JIGSAW,
+                Optional.empty(),
+                true,
+                true,
+                List.of(),
+                new JigsawStudioPieceRules(0, 30, 0, 0, false),
+                List.of());
+        GeneratorFixture fixture = fixture(
+                source,
+                JigsawStudioMode.SPATIAL_JIGSAW,
+                new JigsawStudioCellDimensions(5, 5, 5),
+                new JigsawStudioVariantCatalog(List.of(variant)));
+        JigsawStudioBay workcell = fixture.layout().bays().getFirst();
+        int originX = workcell.bounds().originX();
+        int originZ = workcell.bounds().originZ();
+        int floorY = workcell.bounds().originY() - 1;
+
+        try (MockedStatic<B> ignored = mockStatic(B.class)) {
+            assertSame(fixture.palette().upAndDownSocket(), stateAt(fixture.generator(), originX + 2, floorY, originZ + 2));
+            assertSame(fixture.palette().downSocket(), stateAt(fixture.generator(), originX, floorY, originZ + 4));
+            assertSame(fixture.palette().horizontalSocket(), stateAt(fixture.generator(), originX + 2, floorY, originZ));
+            assertSame(fixture.palette().line(), stateAt(fixture.generator(), originX + 2, floorY, originZ + 1));
+            assertSame(fixture.palette().line(), stateAt(fixture.generator(), originX + 1, floorY, originZ + 3));
+            assertSame(fixture.palette().base(), stateAt(fixture.generator(), originX + 4, floorY, originZ + 4));
+        }
+        assertSame(
+                fixture.palette().upAndDownSocket(),
+                fixture.generator().floorState(fixture.generator().floorGlyph(workcell).cell(2, 2)));
     }
 
     @Test
@@ -247,77 +312,6 @@ public class JigsawStudioGeneratorTest {
                 workcell.bounds().originZ()));
     }
 
-    @Test
-    public void glyphMathHandlesAllArchetypesAndSmallEvenAndOddCells() {
-        int[] sizes = {1, 2, 3, 4, 7, 16};
-        for (int size : sizes) {
-            JigsawStudioCellDimensions dimensions = new JigsawStudioCellDimensions(size, 1, size);
-            int center = size / 2;
-            for (JigsawPlanarArchetype archetype : JigsawPlanarArchetype.values()) {
-                JigsawPlanarTopology topology = archetype.canonicalTopology();
-                boolean centerPath = JigsawStudioGenerator.isTopologyPath(
-                        topology, center, center, center, center);
-                assertEquals(archetype != JigsawPlanarArchetype.BLANK, centerPath);
-                if (topology.connects(JigsawPlanarDirection.NORTH)) {
-                    assertTrue(JigsawStudioGenerator.isConnectorCap(
-                            topology, dimensions, center, 0, center, center));
-                }
-                if (topology.connects(JigsawPlanarDirection.EAST)) {
-                    assertTrue(JigsawStudioGenerator.isConnectorCap(
-                            topology, dimensions, size - 1, center, center, center));
-                }
-            }
-        }
-    }
-
-    @Test
-    public void connectorCapsOnlyOccupyConnectedFaceCenters() {
-        int[] sizes = {3, 4, 7, 16};
-        for (int size : sizes) {
-            JigsawStudioCellDimensions dimensions = new JigsawStudioCellDimensions(size, 1, size);
-            int center = size / 2;
-            for (JigsawPlanarArchetype archetype : JigsawPlanarArchetype.values()) {
-                JigsawPlanarTopology topology = archetype.canonicalTopology();
-                for (int z = 0; z < size; z++) {
-                    for (int x = 0; x < size; x++) {
-                        boolean expected = topology.connects(JigsawPlanarDirection.NORTH)
-                                && x == center && z == 0
-                                || topology.connects(JigsawPlanarDirection.EAST)
-                                && x == size - 1 && z == center
-                                || topology.connects(JigsawPlanarDirection.SOUTH)
-                                && x == center && z == size - 1
-                                || topology.connects(JigsawPlanarDirection.WEST)
-                                && x == 0 && z == center;
-                        assertEquals(expected, JigsawStudioGenerator.isConnectorCap(
-                                topology, dimensions, x, z, center, center));
-                    }
-                }
-            }
-        }
-    }
-
-    @Test
-    public void canonicalFiveByFivePathsMatchEveryArchetype() {
-        Map<JigsawPlanarArchetype, List<String>> expected = Map.of(
-                JigsawPlanarArchetype.BLANK, List.of(".....", ".....", ".....", ".....", "....."),
-                JigsawPlanarArchetype.END, List.of("..#..", "..#..", "..#..", ".....", "....."),
-                JigsawPlanarArchetype.STRAIGHT, List.of("..#..", "..#..", "..#..", "..#..", "..#.."),
-                JigsawPlanarArchetype.CORNER, List.of("..#..", "..#..", "..###", ".....", "....."),
-                JigsawPlanarArchetype.TEE, List.of("..#..", "..#..", "#####", ".....", "....."),
-                JigsawPlanarArchetype.CROSS, List.of("..#..", "..#..", "#####", "..#..", "..#.."));
-
-        for (JigsawPlanarArchetype archetype : JigsawPlanarArchetype.values()) {
-            List<String> rows = expected.get(archetype);
-            for (int z = 0; z < 5; z++) {
-                for (int x = 0; x < 5; x++) {
-                    boolean path = JigsawStudioGenerator.isTopologyPath(
-                            archetype.canonicalTopology(), x, z, 2, 2);
-                    assertEquals(rows.get(z).charAt(x) == '#', path);
-                }
-            }
-        }
-    }
-
     @Test
     public void clipsLargeGlyphPaintingToOneChunkFootprint() {
         GeneratorFixture fixture = fixture(
@@ -331,10 +325,7 @@ public class JigsawStudioGeneratorTest {
 
         fixture.generator().paintChunk(chunk, chunkX, chunkZ);
 
-        int glyphBlocks = chunk.countState(fixture.topologyBase())
+        assertEquals(256, chunk.countState(fixture.palette().base()));
-                + chunk.countState(fixture.topologyPath())
-                + chunk.countState(fixture.connectorCap());
-        assertEquals(256, glyphBlocks);
     }
 
     @Test
@@ -467,6 +458,29 @@ public class JigsawStudioGeneratorTest {
         assertNotSame(nextGeneration, fixture.generator().renderVariant(workcell, variant, 5L));
     }
 
+    @Test
+    public void workcellsFromAnEquivalentReplacedLayoutStillRender() {
+        JigsawStudioCellDimensions dimensions = new JigsawStudioCellDimensions(5, 5, 5);
+        GeneratorFixture fixture = fixture(
+                JigsawStudioMode.PLANAR_JIGSAW,
+                dimensions,
+                JigsawStudioVariantCatalog.empty());
+        JigsawStudioBay stale = fixture.layout().get("workcell/end");
+
+        fixture.generator().getSession().replaceLayout(JigsawStudioLayout.create(
+                JigsawStudioMode.PLANAR_JIGSAW,
+                dimensions,
+                JigsawStudioVariantCatalog.empty()));
+
+        assertNotSame(stale, fixture.generator().getLayout().get("workcell/end"));
+        assertTrue(fixture.generator().renderBay(stale).valid());
+        fixture.generator().getSession().replaceLayout(JigsawStudioLayout.create(
+                JigsawStudioMode.PLANAR_JIGSAW,
+                new JigsawStudioCellDimensions(6, 5, 5),
+                JigsawStudioVariantCatalog.empty()));
+        assertThrows(IllegalArgumentException.class, () -> fixture.generator().renderBay(stale));
+    }
+
     @Test
     public void mapsAllVanillaJigsawOrientations() {
         assertEquals("north_up", JigsawStudioGenerator.orientation(
@@ -535,9 +549,13 @@ public class JigsawStudioGeneratorTest {
         NativeBlockState lightFloor = mock(NativeBlockState.class);
         NativeBlockState darkFloor = mock(NativeBlockState.class);
         NativeBlockState frame = mock(NativeBlockState.class);
-        NativeBlockState topologyBase = mock(NativeBlockState.class);
+        JigsawStudioGenerator.FloorPalette palette = new JigsawStudioGenerator.FloorPalette(
-        NativeBlockState topologyPath = mock(NativeBlockState.class);
+                mock(NativeBlockState.class),
-        NativeBlockState connectorCap = mock(NativeBlockState.class);
+                mock(NativeBlockState.class),
+                mock(NativeBlockState.class),
+                mock(NativeBlockState.class),
+                mock(NativeBlockState.class),
+                mock(NativeBlockState.class));
         NativeBlockState invalidMarker = mock(NativeBlockState.class);
         NativeBlockState controlChest = mock(NativeBlockState.class);
         JigsawStudioGenerator generator = new JigsawStudioGenerator(
@@ -547,9 +565,7 @@ public class JigsawStudioGeneratorTest {
                 lightFloor,
                 darkFloor,
                 frame,
-                topologyBase,
+                palette,
-                topologyPath,
-                connectorCap,
                 invalidMarker,
                 controlChest,
                 JigsawStudioGeneratorTest::renderFinalState);
@@ -557,12 +573,22 @@ public class JigsawStudioGeneratorTest {
                 generator,
                 layout,
                 frame,
-                topologyBase,
+                palette,
-                topologyPath,
-                connectorCap,
                 controlChest);
     }
 
+    private static IrisJigsawConnector connector(IrisPosition position, IrisDirection direction) {
+        return new IrisJigsawConnector()
+                .setPosition(position)
+                .setDirection(direction)
+                .setTop(IrisDirection.UP_POSITIVE_Y)
+                .setPool("test/pieces")
+                .setName("iris:planar")
+                .setTargetName("iris:planar")
+                .setJoint(JigsawJoint.ALIGNED)
+                .setFinalState("minecraft:structure_void");
+    }
+
     private static JigsawStudioVariant planarVariant(String key, JigsawPlanarTopology topology) {
         return new JigsawStudioVariant(
                 key,
@@ -596,9 +622,7 @@ public class JigsawStudioGeneratorTest {
             JigsawStudioGenerator generator,
             JigsawStudioLayout layout,
             NativeBlockState frame,
-            NativeBlockState topologyBase,
+            JigsawStudioGenerator.FloorPalette palette,
-            NativeBlockState topologyPath,
-            NativeBlockState connectorCap,
             NativeBlockState controlChest
     ) {
     }

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawDefaultKitAssemblyTest.java

@@ -0,0 +1,509 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.pack.value.IrisDirection;
+import art.arcane.iris.pack.value.IrisPosition;
+import art.arcane.iris.structure.authoring.StructureResourceBundle;
+import art.arcane.iris.structure.authoring.StructureWriteResult;
+import art.arcane.iris.structure.graph.StructureAssemblyResult;
+import art.arcane.iris.structure.graph.StructureAssemblyStatus;
+import art.arcane.iris.structure.graph.StructureGraphCompilation;
+import art.arcane.iris.structure.graph.StructureResourceBundleGraphCompiler;
+import art.arcane.iris.structure.jigsaw.IrisJigsawConnector;
+import art.arcane.iris.structure.jigsaw.IrisJigsawPiece;
+import art.arcane.iris.structure.jigsaw.IrisJigsawPieceEntry;
+import art.arcane.iris.structure.jigsaw.IrisJigsawPool;
+import art.arcane.iris.structure.jigsaw.JigsawJoint;
+import art.arcane.iris.structure.object.IrisObject;
+import art.arcane.iris.structure.placement.IrisStructure;
+import art.arcane.iris.structure.placement.PlacedStructurePiece;
+import art.arcane.iris.structure.placement.StructureAssembler;
+import art.arcane.iris.testsupport.DurabilityMode;
+import art.arcane.volmlib.util.math.RNG;
+import com.google.gson.Gson;
+import org.junit.ClassRule;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeMap;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+public class JigsawDefaultKitAssemblyTest {
+    @ClassRule
+    public static final DurabilityMode DURABILITY = DurabilityMode.relaxed();
+
+    private static final Gson GSON = new Gson();
+    private static final int SEEDS = 160;
+    private static final int SPATIAL_IRIS_PIECE_BOUND = 23 * 4 + 1;
+    private static final int SPATIAL_PORTABLE_PIECE_BOUND = 129;
+    private static final List<JigsawStudioCellDimensions> PLANAR_DIMENSIONS = List.of(
+            new JigsawStudioCellDimensions(16, 16, 16),
+            new JigsawStudioCellDimensions(15, 9, 15));
+    private static final List<JigsawStudioCellDimensions> SPATIAL_DIMENSIONS = List.of(
+            new JigsawStudioCellDimensions(15, 15, 15),
+            new JigsawStudioCellDimensions(16, 12, 16));
+
+    @Rule
+    public TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+    @Test
+    public void planarDefaultKitOpensEveryOccupiedNeighborOnTheCellGrid() throws IOException {
+        for (JigsawStudioCellDimensions dimensions : PLANAR_DIMENSIONS) {
+            for (JigsawStudioCompatibilityTarget target : JigsawStudioCompatibilityTarget.values()) {
+                StructureGraphCompilation compilation = compile(JigsawStudioMode.PLANAR_JIGSAW, target, dimensions);
+                int closedFaces = 0;
+                for (long seed = 0; seed < SEEDS; seed++) {
+                    List<PlacedStructurePiece> pieces = complete(compilation, seed);
+                    for (PlacedStructurePiece piece : pieces) {
+                        for (IrisJigsawConnector connector : piece.getPiece().getConnectors()) {
+                            IrisDirection facing = piece.getRotation().rotate(connector.getDirection());
+                            IrisPosition targetCell = offset(planarSocket(piece, facing), facing);
+                            PlacedStructurePiece neighbor = containing(pieces, targetCell);
+                            if (neighbor == null) {
+                                continue;
+                            }
+                            String context = target + " " + dimensions + " seed " + seed + ": "
+                                    + piece.getPiece().getObject() + " faces " + facing + " into "
+                                    + neighbor.getPiece().getObject();
+                            assertTrue(context, hasPlanarSocket(
+                                    neighbor,
+                                    facing.reverse(),
+                                    targetCell,
+                                    piece.getRotation().rotate(connector.getTop())));
+                            assertSharedFace(context, piece, neighbor, facing);
+                            closedFaces++;
+                        }
+                    }
+                }
+                assertTrue(closedFaces > SEEDS);
+            }
+        }
+    }
+
+    @Test
+    public void planarDefaultKitTurnsBothWaysThroughCornersAndTees() throws IOException {
+        StructureGraphCompilation compilation = compile(
+                JigsawStudioMode.PLANAR_JIGSAW,
+                JigsawStudioCompatibilityTarget.IRIS_EXTENDED,
+                PLANAR_DIMENSIONS.getFirst());
+        Map<String, Set<Integer>> attachments = new TreeMap<>();
+        for (long seed = 0; seed < SEEDS; seed++) {
+            List<PlacedStructurePiece> pieces = complete(compilation, seed);
+            for (int index = 1; index < pieces.size(); index++) {
+                PlacedStructurePiece piece = pieces.get(index);
+                int attachment = soleEarlierPlanarAttachment(pieces, index);
+                if (attachment >= 0) {
+                    attachments.computeIfAbsent(baseName(piece), ignored -> new HashSet<>()).add(attachment);
+                }
+            }
+        }
+        assertEquals(attachments.toString(), Set.of(0, 1), attachments.get("corner"));
+        Set<Integer> teeAttachments = attachments.get("tee");
+        assertNotNull(attachments.toString(), teeAttachments);
+        assertTrue(attachments.toString(), teeAttachments.contains(0));
+        assertTrue(attachments.toString(), teeAttachments.contains(1) || teeAttachments.contains(2));
+    }
+
+    @Test
+    public void connectorlessBlankPiecesGenerateAsStandaloneStructures() throws IOException {
+        for (JigsawStudioMode mode : JigsawStudioMode.values()) {
+            JigsawStudioCellDimensions dimensions = mode == JigsawStudioMode.PLANAR_JIGSAW
+                    ? PLANAR_DIMENSIONS.getFirst()
+                    : SPATIAL_DIMENSIONS.getFirst();
+            StructureGraphCompilation compilation = compile(
+                    mode,
+                    JigsawStudioCompatibilityTarget.IRIS_EXTENDED,
+                    dimensions);
+            int standaloneBlanks = 0;
+            int multiPieceAssemblies = 0;
+            for (long seed = 0; seed < SEEDS * 8 && (standaloneBlanks == 0 || seed < SEEDS); seed++) {
+                List<PlacedStructurePiece> pieces = complete(compilation, seed);
+                if (pieces.size() == 1 && pieces.getFirst().getPiece().getConnectors().isEmpty()) {
+                    assertEquals("blank", baseName(pieces.getFirst()));
+                    standaloneBlanks++;
+                    continue;
+                }
+                multiPieceAssemblies++;
+                for (PlacedStructurePiece piece : pieces) {
+                    assertFalse(mode + " seed " + seed, piece.getPiece().getConnectors().isEmpty());
+                }
+            }
+            assertTrue(mode + " never generated its connectorless piece", standaloneBlanks > 0);
+            assertTrue(mode + " generated only standalone pieces", multiPieceAssemblies > standaloneBlanks);
+        }
+
+        StructureResourceBundle planar = JigsawStudioProjectCreator.bundle(options(
+                JigsawStudioMode.PLANAR_JIGSAW,
+                JigsawStudioCompatibilityTarget.VANILLA_PORTABLE,
+                PLANAR_DIMENSIONS.getLast()));
+        IrisJigsawPool start = pool(planar, "kit/test/start");
+        assertEquals(2, start.getPieces().size());
+        assertEquals("kit/test/cross", start.getPieces().get(0).getPiece());
+        assertEquals(3, start.getPieces().get(0).getWeight());
+        assertEquals("kit/test/blank", start.getPieces().get(1).getPiece());
+        assertEquals(1, start.getPieces().get(1).getWeight());
+        for (IrisJigsawPieceEntry entry : pool(planar, "kit/test/pieces").getPieces()) {
+            assertFalse("kit/test/blank".equals(entry.getPiece()));
+        }
+    }
+
+    @Test
+    public void spatialDefaultKitCoversEveryYRotationTopologyOnce() throws IOException {
+        for (JigsawStudioCompatibilityTarget target : JigsawStudioCompatibilityTarget.values()) {
+            JigsawStudioCellDimensions dimensions = SPATIAL_DIMENSIONS.getLast();
+            StructureResourceBundle bundle = JigsawStudioProjectCreator.bundle(
+                    options(JigsawStudioMode.SPATIAL_JIGSAW, target, dimensions));
+            Map<String, IrisJigsawPiece> pieces = pieces(bundle);
+            Map<Integer, String> bySignature = new HashMap<>();
+            for (Map.Entry<String, IrisJigsawPiece> entry : pieces.entrySet()) {
+                IrisJigsawPiece piece = entry.getValue();
+                int horizontal = 0;
+                int vertical = 0;
+                for (IrisJigsawConnector connector : piece.getConnectors()) {
+                    IrisDirection direction = connector.getDirection();
+                    assertEquals(spatialFaceCenter(dimensions, direction), connector.getPosition());
+                    assertEquals(direction.isVertical() ? IrisDirection.NORTH_NEGATIVE_Z : IrisDirection.UP_POSITIVE_Y,
+                            connector.getTop());
+                    assertEquals(JigsawJoint.ROLLABLE, connector.getJoint());
+                    assertEquals("kit/test/pieces", connector.getPool());
+                    horizontal |= horizontalBit(direction);
+                    vertical |= verticalBit(direction);
+                }
+                assertTrue(piece.isRotatable());
+                assertEquals(entry.getKey(), piece.getObject());
+                assertEquals(expectedSpatialKey(canonicalMask(horizontal), vertical), entry.getKey());
+                String previous = bySignature.put(canonicalMask(horizontal) | vertical, entry.getKey());
+                assertEquals("duplicate topology " + entry.getKey() + " and " + previous, null, previous);
+                if (target == JigsawStudioCompatibilityTarget.IRIS_EXTENDED) {
+                    assertEquals(List.of("variant-1"), List.copyOf(piece.getThemes()));
+                    assertEquals(4, piece.resolvedRules().getMaximumPlacements());
+                } else {
+                    assertTrue(piece.getThemes().isEmpty());
+                    assertEquals(0, piece.resolvedRules().getMaximumPlacements());
+                }
+            }
+            assertEquals(24, pieces.size());
+            assertEquals(24, bySignature.size());
+
+            IrisJigsawPool start = pool(bundle, "kit/test/start");
+            assertEquals(24, start.getPieces().size());
+            IrisJigsawPool piecePool = pool(bundle, "kit/test/pieces");
+            assertEquals(24, piecePool.getPieces().size());
+            assertTrue(piecePool.getPieces().getLast().isEmpty());
+            for (IrisJigsawPieceEntry entry : piecePool.getPieces()) {
+                assertFalse("kit/test/blank".equals(entry.getPiece()));
+            }
+        }
+    }
+
+    @Test
+    public void spatialDefaultKitAttachesEveryPieceThroughAlignedConnectorsAndTurnsBothWays() throws IOException {
+        for (JigsawStudioCellDimensions dimensions : SPATIAL_DIMENSIONS) {
+            for (JigsawStudioCompatibilityTarget target : JigsawStudioCompatibilityTarget.values()) {
+                StructureGraphCompilation compilation = compile(JigsawStudioMode.SPATIAL_JIGSAW, target, dimensions);
+                int bound = target == JigsawStudioCompatibilityTarget.IRIS_EXTENDED
+                        ? SPATIAL_IRIS_PIECE_BOUND
+                        : SPATIAL_PORTABLE_PIECE_BOUND;
+                Set<String> placedKinds = new HashSet<>();
+                Set<Integer> cornerAttachments = new HashSet<>();
+                for (long seed = 0; seed < SEEDS; seed++) {
+                    List<PlacedStructurePiece> pieces = complete(compilation, seed);
+                    String context = target + " " + dimensions + " seed " + seed;
+                    assertTrue(context + " placed " + pieces.size(), pieces.size() <= bound);
+                    for (int index = 0; index < pieces.size(); index++) {
+                        placedKinds.add(baseName(pieces.get(index)));
+                        if (index == 0) {
+                            continue;
+                        }
+                        List<Integer> attachments = earlierSpatialAttachments(pieces, index);
+                        assertFalse(context + " left " + baseName(pieces.get(index)) + " unattached",
+                                attachments.isEmpty());
+                        if (attachments.size() == 1 && baseName(pieces.get(index)).startsWith("corner")
+                                && attachments.getFirst() < 2) {
+                            cornerAttachments.add(attachments.getFirst());
+                        }
+                    }
+                }
+                assertEquals(target + " " + dimensions, Set.of(0, 1), cornerAttachments);
+                assertFalse(placedKinds.contains("blank"));
+                assertEquals(target + " " + dimensions + " placed " + placedKinds, 23, placedKinds.size());
+            }
+        }
+    }
+
+    @Test
+    public void vanillaPortableSpatialProjectIsCreatedWithAViableGraph() throws IOException {
+        Path packRoot = temporaryFolder.getRoot().toPath();
+        JigsawStudioProjectCreator.Options options = options(
+                JigsawStudioMode.SPATIAL_JIGSAW,
+                JigsawStudioCompatibilityTarget.VANILLA_PORTABLE,
+                SPATIAL_DIMENSIONS.getFirst());
+
+        StructureWriteResult result = JigsawStudioProjectCreator.create(packRoot, options);
+
+        assertTrue(result.successful());
+        IrisStructure structure = GSON.fromJson(Files.readString(
+                packRoot.resolve("structures/kit/test.json"), StandardCharsets.UTF_8), IrisStructure.class);
+        assertEquals(4, structure.getMaxDepth());
+        assertTrue(Files.isRegularFile(packRoot.resolve("jigsaw-pieces/kit/test/corner-up-down.json")));
+        assertTrue(Files.isRegularFile(packRoot.resolve("objects/kit/test/blank.iob")));
+    }
+
+    private static JigsawStudioProjectCreator.Options options(
+            JigsawStudioMode mode,
+            JigsawStudioCompatibilityTarget target,
+            JigsawStudioCellDimensions dimensions
+    ) {
+        return new JigsawStudioProjectCreator.Options("kit/test", mode, target, dimensions);
+    }
+
+    private static StructureGraphCompilation compile(
+            JigsawStudioMode mode,
+            JigsawStudioCompatibilityTarget target,
+            JigsawStudioCellDimensions dimensions
+    ) throws IOException {
+        StructureGraphCompilation compilation = StructureResourceBundleGraphCompiler.compile(
+                JigsawStudioProjectCreator.bundle(options(mode, target, dimensions))).getFirst();
+        assertFalse(compilation.getDiagnostics().toString(), compilation.hasErrors());
+        return compilation;
+    }
+
+    private static List<PlacedStructurePiece> complete(StructureGraphCompilation compilation, long seed) {
+        StructureAssemblyResult result = StructureAssembler.forCompilation(
+                compilation,
+                new IrisPosition(0, 64, 0)).assemble(new RNG(seed));
+        assertEquals("seed " + seed + ": " + result.detail(), StructureAssemblyStatus.COMPLETE, result.status());
+        return result.pieces();
+    }
+
+    private static int soleEarlierPlanarAttachment(List<PlacedStructurePiece> pieces, int index) {
+        PlacedStructurePiece piece = pieces.get(index);
+        int attachment = -1;
+        int pairings = 0;
+        for (int connectorIndex = 0; connectorIndex < piece.getPiece().getConnectors().size(); connectorIndex++) {
+            IrisJigsawConnector connector = piece.getPiece().getConnectors().get(connectorIndex);
+            IrisDirection facing = piece.getRotation().rotate(connector.getDirection());
+            IrisPosition targetCell = offset(planarSocket(piece, facing), facing);
+            for (int earlier = 0; earlier < index; earlier++) {
+                PlacedStructurePiece neighbor = pieces.get(earlier);
+                if (contains(neighbor, targetCell) && hasPlanarSocket(
+                        neighbor,
+                        facing.reverse(),
+                        targetCell,
+                        piece.getRotation().rotate(connector.getTop()))) {
+                    attachment = connectorIndex;
+                    pairings++;
+                }
+            }
+        }
+        return pairings == 1 ? attachment : -1;
+    }
+
+    private static List<Integer> earlierSpatialAttachments(List<PlacedStructurePiece> pieces, int index) {
+        PlacedStructurePiece piece = pieces.get(index);
+        List<Integer> attachments = new ArrayList<>();
+        for (int connectorIndex = 0; connectorIndex < piece.getPiece().getConnectors().size(); connectorIndex++) {
+            IrisJigsawConnector connector = piece.getPiece().getConnectors().get(connectorIndex);
+            IrisPosition socket = spatialSocket(piece, connector);
+            IrisDirection facing = piece.getRotation().rotate(connector.getDirection());
+            for (int earlier = 0; earlier < index; earlier++) {
+                PlacedStructurePiece neighbor = pieces.get(earlier);
+                for (IrisJigsawConnector other : neighbor.getPiece().getConnectors()) {
+                    IrisDirection otherFacing = neighbor.getRotation().rotate(other.getDirection());
+                    if (otherFacing == facing.reverse()
+                            && offset(spatialSocket(neighbor, other), otherFacing).equals(socket)) {
+                        attachments.add(connectorIndex);
+                    }
+                }
+            }
+        }
+        return attachments;
+    }
+
+    private static boolean hasPlanarSocket(
+            PlacedStructurePiece piece,
+            IrisDirection facing,
+            IrisPosition position,
+            IrisDirection top
+    ) {
+        if (!planarSocket(piece, facing).equals(position)) {
+            return false;
+        }
+        for (IrisJigsawConnector connector : piece.getPiece().getConnectors()) {
+            if (piece.getRotation().rotate(connector.getDirection()) == facing
+                    && piece.getRotation().rotate(connector.getTop()) == top) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private static void assertSharedFace(
+            String context,
+            PlacedStructurePiece piece,
+            PlacedStructurePiece neighbor,
+            IrisDirection facing
+    ) {
+        assertEquals(context, piece.getMinY(), neighbor.getMinY());
+        assertEquals(context, piece.getMaxY(), neighbor.getMaxY());
+        switch (facing) {
+            case EAST_POSITIVE_X -> assertEquals(context, piece.getMaxX() + 1, neighbor.getMinX());
+            case WEST_NEGATIVE_X -> assertEquals(context, piece.getMinX() - 1, neighbor.getMaxX());
+            case SOUTH_POSITIVE_Z -> assertEquals(context, piece.getMaxZ() + 1, neighbor.getMinZ());
+            case NORTH_NEGATIVE_Z -> assertEquals(context, piece.getMinZ() - 1, neighbor.getMaxZ());
+            case UP_POSITIVE_Y, DOWN_NEGATIVE_Y -> throw new AssertionError(context + " uses a vertical socket");
+        }
+        if (facing.x() != 0) {
+            assertEquals(context, piece.getMinZ(), neighbor.getMinZ());
+            assertEquals(context, piece.getMaxZ(), neighbor.getMaxZ());
+        } else {
+            assertEquals(context, piece.getMinX(), neighbor.getMinX());
+            assertEquals(context, piece.getMaxX(), neighbor.getMaxX());
+        }
+    }
+
+    private static IrisPosition planarSocket(PlacedStructurePiece piece, IrisDirection facing) {
+        IrisPosition size = new IrisPosition(
+                piece.getMaxX() - piece.getMinX() + 1,
+                piece.getMaxY() - piece.getMinY() + 1,
+                piece.getMaxZ() - piece.getMinZ() + 1);
+        IrisPosition local = IrisJigsawConnector.canonicalPlanarPosition(size, facing);
+        return new IrisPosition(
+                piece.getMinX() + local.getX(),
+                piece.getMinY() + local.getY(),
+                piece.getMinZ() + local.getZ());
+    }
+
+    private static IrisPosition spatialSocket(PlacedStructurePiece piece, IrisJigsawConnector connector) {
+        IrisObject object = piece.getObject();
+        IrisPosition relative = new IrisPosition(
+                connector.getPosition().getX() - object.getW() / 2,
+                connector.getPosition().getY() - object.getH() / 2,
+                connector.getPosition().getZ() - object.getD() / 2);
+        IrisPosition rotated = piece.getRotation().rotate(relative);
+        return new IrisPosition(
+                piece.getX() + rotated.getX(),
+                piece.getY() + rotated.getY(),
+                piece.getZ() + rotated.getZ());
+    }
+
+    private static IrisPosition spatialFaceCenter(JigsawStudioCellDimensions dimensions, IrisDirection direction) {
+        int centerX = dimensions.width() / 2;
+        int centerY = dimensions.height() / 2;
+        int centerZ = dimensions.depth() / 2;
+        return switch (direction) {
+            case NORTH_NEGATIVE_Z -> new IrisPosition(centerX, centerY, 0);
+            case SOUTH_POSITIVE_Z -> new IrisPosition(centerX, centerY, dimensions.depth() - 1);
+            case EAST_POSITIVE_X -> new IrisPosition(dimensions.width() - 1, centerY, centerZ);
+            case WEST_NEGATIVE_X -> new IrisPosition(0, centerY, centerZ);
+            case UP_POSITIVE_Y -> new IrisPosition(centerX, dimensions.height() - 1, centerZ);
+            case DOWN_NEGATIVE_Y -> new IrisPosition(centerX, 0, centerZ);
+        };
+    }
+
+    private static IrisPosition offset(IrisPosition position, IrisDirection direction) {
+        return new IrisPosition(
+                position.getX() + direction.x(),
+                position.getY() + direction.y(),
+                position.getZ() + direction.z());
+    }
+
+    private static PlacedStructurePiece containing(List<PlacedStructurePiece> pieces, IrisPosition position) {
+        for (PlacedStructurePiece piece : pieces) {
+            if (contains(piece, position)) {
+                return piece;
+            }
+        }
+        return null;
+    }
+
+    private static boolean contains(PlacedStructurePiece piece, IrisPosition position) {
+        return position.getX() >= piece.getMinX() && position.getX() <= piece.getMaxX()
+                && position.getY() >= piece.getMinY() && position.getY() <= piece.getMaxY()
+                && position.getZ() >= piece.getMinZ() && position.getZ() <= piece.getMaxZ();
+    }
+
+    private static String baseName(PlacedStructurePiece piece) {
+        String key = piece.getPiece().getObject();
+        return key.substring(key.lastIndexOf('/') + 1);
+    }
+
+    private static int horizontalBit(IrisDirection direction) {
+        return switch (direction) {
+            case NORTH_NEGATIVE_Z -> 1;
+            case EAST_POSITIVE_X -> 2;
+            case SOUTH_POSITIVE_Z -> 4;
+            case WEST_NEGATIVE_X -> 8;
+            case UP_POSITIVE_Y, DOWN_NEGATIVE_Y -> 0;
+        };
+    }
+
+    private static int verticalBit(IrisDirection direction) {
+        return switch (direction) {
+            case UP_POSITIVE_Y -> 16;
+            case DOWN_NEGATIVE_Y -> 32;
+            case NORTH_NEGATIVE_Z, EAST_POSITIVE_X, SOUTH_POSITIVE_Z, WEST_NEGATIVE_X -> 0;
+        };
+    }
+
+    private static int canonicalMask(int mask) {
+        int canonical = mask;
+        for (int quarterTurns = 1; quarterTurns < 4; quarterTurns++) {
+            canonical = Math.min(canonical, ((mask << quarterTurns) | (mask >>> (4 - quarterTurns))) & 15);
+        }
+        return canonical;
+    }
+
+    private static String expectedSpatialKey(int canonicalHorizontal, int vertical) {
+        String horizontal = switch (canonicalHorizontal) {
+            case 0 -> "blank";
+            case 1 -> "end";
+            case 3 -> "corner";
+            case 5 -> "straight";
+            case 7 -> "tee";
+            case 15 -> "cross";
+            default -> throw new AssertionError("Unexpected horizontal topology " + canonicalHorizontal);
+        };
+        String suffix = switch (vertical) {
+            case 0 -> "";
+            case 16 -> "-up";
+            case 32 -> "-down";
+            case 48 -> "-up-down";
+            default -> throw new AssertionError("Unexpected vertical topology " + vertical);
+        };
+        return "kit/test/" + horizontal + suffix;
+    }
+
+    private static Map<String, IrisJigsawPiece> pieces(StructureResourceBundle bundle) {
+        Map<String, IrisJigsawPiece> pieces = new TreeMap<>();
+        for (StructureResourceBundle.Resource resource : bundle.resources().values()) {
+            String path = resource.relativePath();
+            if (path.startsWith("jigsaw-pieces/") && path.endsWith(".json")) {
+                pieces.put(
+                        path.substring("jigsaw-pieces/".length(), path.length() - ".json".length()),
+                        GSON.fromJson(new String(resource.content(), StandardCharsets.UTF_8), IrisJigsawPiece.class));
+            }
+        }
+        return pieces;
+    }
+
+    private static IrisJigsawPool pool(StructureResourceBundle bundle, String key) {
+        StructureResourceBundle.Resource resource = bundle.resources().get("jigsaw-pools/" + key + ".json");
+        assertNotNull(key, resource);
+        return GSON.fromJson(new String(resource.content(), StandardCharsets.UTF_8), IrisJigsawPool.class);
+    }
+}

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioCaptureFinalStateTest.java

@@ -0,0 +1,101 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.pack.value.IrisDirection;
+import art.arcane.iris.pack.value.IrisPosition;
+import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.structure.jigsaw.IrisJigsawConnector;
+import art.arcane.iris.structure.jigsaw.IrisJigsawPiece;
+import art.arcane.iris.structure.jigsaw.JigsawJoint;
+import art.arcane.iris.structure.object.IrisObject;
+import art.arcane.volmlib.nativelib.terrain.NativeBlockState;
+import art.arcane.volmlib.util.collection.KList;
+import org.bukkit.Bukkit;
+import org.bukkit.Material;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.block.data.BlockData;
+import org.bukkit.entity.Player;
+import org.junit.Test;
+import org.mockito.MockedStatic;
+
+import java.io.ByteArrayInputStream;
+import java.util.List;
+import java.util.UUID;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.when;
+
+public class JigsawStudioCaptureFinalStateTest {
+    @Test
+    public void hiddenConnectorOverDugOutAirStoresExplicitAirLikeVisibleMarkers() throws Throwable {
+        JigsawStudioBounds bounds = new JigsawStudioBounds(0, 64, 0, new JigsawStudioCellDimensions(1, 1, 1));
+        IrisJigsawPiece piece = new IrisJigsawPiece().setConnectors(new KList<>());
+        piece.getConnectors().add(new IrisJigsawConnector()
+                .setPosition(new IrisPosition(0, 0, 0))
+                .setDirection(IrisDirection.NORTH_NEGATIVE_Z)
+                .setTop(IrisDirection.UP_POSITIVE_Y)
+                .setPool("fort/pieces")
+                .setName("iris:door")
+                .setTargetName("iris:door")
+                .setJoint(JigsawJoint.ALIGNED)
+                .setFinalState("minecraft:structure_void"));
+        BlockData air = mock(BlockData.class);
+        when(air.getMaterial()).thenReturn(Material.AIR);
+        when(air.getAsString()).thenReturn("minecraft:air");
+        Block block = mock(Block.class);
+        when(block.getBlockData()).thenReturn(air);
+        World world = mock(World.class);
+        when(world.getBlockAt(0, 64, 0)).thenReturn(block);
+        JigsawStudioCapture.ChunkCaptureArea area = JigsawStudioCapture.chunkIntersections(bounds).getFirst();
+
+        JigsawStudioCapture.ChunkSnapshot snapshot = JigsawStudioCapture.captureChunkIntersection(
+                world, bounds, piece, new IrisObject(1, 1, 1), area, 0, false);
+        JigsawStudioCapture.Capture capture = JigsawStudioCapture.aggregateSnapshots(
+                bounds, List.of(area), List.of(snapshot));
+
+        assertEquals("minecraft:air", capture.connectors().getFirst().getFinalState());
+        NativeBlockState restoredAir = mock(NativeBlockState.class);
+        when(restoredAir.key()).thenReturn("minecraft:air");
+        IrisObject restored = read(capture.objectContent(), restoredAir);
+        assertTrue(restored.getBlocks().containsKey(restored.getSigned(0, 0, 0)));
+        assertEquals("minecraft:air", restored.getBlocks().get(restored.getSigned(0, 0, 0)).key());
+    }
+
+    @Test
+    public void autosaveNotificationsFallBackToTheOnlineOwner() {
+        Player explicit = mock(Player.class);
+        Player owner = mock(Player.class);
+        UUID ownerId = UUID.randomUUID();
+        try (MockedStatic<Bukkit> server = mockStatic(Bukkit.class)) {
+            server.when(() -> Bukkit.getPlayer(ownerId)).thenReturn(owner);
+
+            assertSame(explicit, JigsawStudioCaptureScheduler.notificationTarget(explicit, ownerId));
+            assertSame(owner, JigsawStudioCaptureScheduler.notificationTarget(null, ownerId));
+            assertNull(JigsawStudioCaptureScheduler.notificationTarget(null, null));
+        }
+    }
+
+    private static IrisObject read(byte[] content, NativeBlockState restoredState) throws Throwable {
+        PlatformRegistries registries = mock(PlatformRegistries.class);
+        when(registries.block(anyString())).thenReturn(restoredState);
+        IrisPlatform platform = mock(IrisPlatform.class);
+        when(platform.registries()).thenReturn(registries);
+        IrisPlatforms.unbind();
+        IrisPlatforms.bind(platform);
+        try {
+            IrisObject restored = new IrisObject();
+            restored.read(new ByteArrayInputStream(content));
+            return restored;
+        } finally {
+            IrisPlatforms.unbind();
+        }
+    }
+}

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioConnectorPlacementTest.java

@@ -0,0 +1,383 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.pack.value.IrisDirection;
+import art.arcane.iris.pack.value.IrisPosition;
+import art.arcane.iris.structure.jigsaw.IrisJigsawConnector;
+import art.arcane.iris.structure.jigsaw.JigsawJoint;
+import art.arcane.iris.studio.jigsaw.JigsawStudioCapture.LocalPosition;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Box;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.BlockClick;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Cell;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.CellContent;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.CellContents;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Decision;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Frame;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Identity;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Operation;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Ray;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.ReseatResult;
+import art.arcane.iris.studio.jigsaw.JigsawStudioConnectorPlacement.Target;
+import org.junit.Test;
+
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
+
+public class JigsawStudioConnectorPlacementTest {
+    private static final Box BOX = new Box(16, 65, 16, 20, 69, 20);
+    private static final CellContents EMPTY = position -> Optional.empty();
+    private static final Identity SPATIAL = new Identity("demo/pieces", "iris:spatial", "iris:spatial", JigsawJoint.ROLLABLE);
+
+    @Test
+    public void clickedBlockInsideTheVariantBecomesTheConnectorFacingOutOfTheClickedFace() {
+        Optional<Target> target = JigsawStudioConnectorPlacement.target(
+                BOX,
+                new Ray(18.5D, 67.5D, 25.0D, 0.0D, 0.0D, -1.0D),
+                Optional.of(new BlockClick(18, 67, 20, IrisDirection.SOUTH_POSITIVE_Z)),
+                Set.of(),
+                false);
+
+        assertEquals(Optional.of(new Target(18, 67, 20, IrisDirection.SOUTH_POSITIVE_Z)), target);
+    }
+
+    @Test
+    public void sneakingFacesTheConnectorIntoTheClickedFace() {
+        Optional<Target> target = JigsawStudioConnectorPlacement.target(
+                BOX,
+                new Ray(18.5D, 67.5D, 25.0D, 0.0D, 0.0D, -1.0D),
+                Optional.of(new BlockClick(18, 67, 20, IrisDirection.SOUTH_POSITIVE_Z)),
+                Set.of(),
+                true);
+
+        assertEquals(Optional.of(new Target(18, 67, 20, IrisDirection.NORTH_NEGATIVE_Z)), target);
+    }
+
+    @Test
+    public void clickingTheStudioFloorPlacesADownConnectorOnTheBottomLayer() {
+        Optional<Target> target = JigsawStudioConnectorPlacement.target(
+                BOX,
+                new Ray(18.5D, 70.0D, 18.5D, 0.0D, -1.0D, 0.0D),
+                Optional.of(new BlockClick(18, 64, 18, IrisDirection.UP_POSITIVE_Y)),
+                Set.of(),
+                false);
+
+        assertEquals(Optional.of(new Target(18, 65, 18, IrisDirection.DOWN_NEGATIVE_Y)), target);
+    }
+
+    @Test
+    public void pointingAtAirFromInsideUsesTheBoundaryCellWhereTheRayLeaves() {
+        Optional<Target> target = JigsawStudioConnectorPlacement.target(
+                BOX,
+                new Ray(18.5D, 67.5D, 18.5D, 0.0D, 0.0D, -1.0D),
+                Optional.empty(),
+                Set.of(),
+                false);
+
+        assertEquals(Optional.of(new Target(18, 67, 16, IrisDirection.NORTH_NEGATIVE_Z)), target);
+    }
+
+    @Test
+    public void pointingAtAirFromOutsideUsesTheBoundaryCellWhereTheRayEnters() {
+        Optional<Target> target = JigsawStudioConnectorPlacement.target(
+                BOX,
+                new Ray(18.5D, 67.5D, 30.0D, 0.0D, 0.0D, -1.0D),
+                Optional.empty(),
+                Set.of(),
+                false);
+
+        assertEquals(Optional.of(new Target(18, 67, 20, IrisDirection.SOUTH_POSITIVE_Z)), target);
+    }
+
+    @Test
+    public void connectorCellsInFrontOfTheClickedBlockWinSoHiddenConnectorsStaySelectable() {
+        Optional<Target> target = JigsawStudioConnectorPlacement.target(
+                BOX,
+                new Ray(18.5D, 67.5D, 18.5D, 0.0D, 0.0D, -1.0D),
+                Optional.of(new BlockClick(18, 67, 16, IrisDirection.SOUTH_POSITIVE_Z)),
+                Set.of(new Cell(18, 67, 17)),
+                false);
+
+        assertEquals(Optional.of(new Target(18, 67, 17, IrisDirection.SOUTH_POSITIVE_Z)), target);
+    }
+
+    @Test
+    public void raysThatMissTheVariantResolveNothing() {
+        Optional<Target> target = JigsawStudioConnectorPlacement.target(
+                BOX,
+                new Ray(30.5D, 67.5D, 30.5D, 0.0D, 0.0D, 1.0D),
+                Optional.empty(),
+                Set.of(),
+                false);
+
+        assertTrue(target.isEmpty());
+    }
+
+    @Test
+    public void spatialRightClicksAddSelectMoveReorientAndDeselect() {
+        LocalPosition door = new LocalPosition(2, 1, 0);
+        LocalPosition other = new LocalPosition(4, 1, 2);
+        LocalPosition empty = new LocalPosition(0, 1, 2);
+        Map<LocalPosition, IrisDirection> connectors = Map.of(
+                door, IrisDirection.NORTH_NEGATIVE_Z,
+                other, IrisDirection.EAST_POSITIVE_X);
+
+        assertEquals(Operation.ADD, spatial(false, empty, IrisDirection.WEST_NEGATIVE_X, connectors, null));
+        assertEquals(Operation.SELECT, spatial(false, door, IrisDirection.NORTH_NEGATIVE_Z, connectors, null));
+        assertEquals(Operation.MOVE, spatial(false, empty, IrisDirection.WEST_NEGATIVE_X, connectors, door));
+        assertEquals(Operation.DESELECT, spatial(false, door, IrisDirection.NORTH_NEGATIVE_Z, connectors, door));
+        assertEquals(Operation.REORIENT, spatial(false, door, IrisDirection.UP_POSITIVE_Y, connectors, door));
+        assertEquals(Operation.SELECT, spatial(false, other, IrisDirection.EAST_POSITIVE_X, connectors, door));
+        assertEquals(Operation.ADD, spatial(false, empty, IrisDirection.WEST_NEGATIVE_X, connectors, empty));
+    }
+
+    @Test
+    public void spatialLeftClicksRemoveOrClearTheSelection() {
+        LocalPosition door = new LocalPosition(2, 1, 0);
+        Map<LocalPosition, IrisDirection> connectors = Map.of(door, IrisDirection.NORTH_NEGATIVE_Z);
+        LocalPosition empty = new LocalPosition(1, 1, 1);
+
+        assertEquals(Operation.REMOVE, spatial(true, door, IrisDirection.NORTH_NEGATIVE_Z, connectors, null));
+        assertEquals(Operation.CLEAR_SELECTION, spatial(true, empty, IrisDirection.UP_POSITIVE_Y, connectors, door));
+        assertEquals(Operation.NONE, spatial(true, empty, IrisDirection.UP_POSITIVE_Y, connectors, null));
+    }
+
+    @Test
+    public void planarRightClicksReseatOnlyTheWorkcellsTopologySides() {
+        JigsawStudioCellDimensions dimensions = new JigsawStudioCellDimensions(5, 5, 5);
+        Map<LocalPosition, IrisDirection> connectors = Map.of();
+
+        Decision east = JigsawStudioConnectorPlacement.decidePlanar(false, new LocalPosition(4, 2, 2),
+                IrisDirection.EAST_POSITIVE_X, dimensions, JigsawPlanarTopology.NORTH_EAST_WEST_TEE, connectors, "T Junction");
+        Decision south = JigsawStudioConnectorPlacement.decidePlanar(false, new LocalPosition(2, 2, 4),
+                IrisDirection.SOUTH_POSITIVE_Z, dimensions, JigsawPlanarTopology.NORTH_EAST_WEST_TEE, connectors, "T Junction");
+        Decision floor = JigsawStudioConnectorPlacement.decidePlanar(false, new LocalPosition(0, 0, 3),
+                IrisDirection.DOWN_NEGATIVE_Y, dimensions, JigsawPlanarTopology.NORTH_EAST_WEST_TEE, connectors, "T Junction");
+
+        assertEquals(Operation.RESEAT, east.operation());
+        assertEquals(JigsawPlanarDirection.EAST, east.side());
+        assertEquals(Operation.REFUSE, south.operation());
+        assertTrue(south.message().contains("north, east, and west"));
+        assertEquals(Operation.RESEAT, floor.operation());
+        assertEquals(JigsawPlanarDirection.WEST, floor.side());
+    }
+
+    @Test
+    public void planarLeftClicksRefuseTheOnlySocketOfAConnectedSideButRemoveStrays() {
+        JigsawStudioCellDimensions dimensions = new JigsawStudioCellDimensions(5, 5, 5);
+        LocalPosition socket = new LocalPosition(2, 2, 0);
+        LocalPosition stray = new LocalPosition(1, 2, 0);
+        Map<LocalPosition, IrisDirection> single = Map.of(socket, IrisDirection.NORTH_NEGATIVE_Z);
+        Map<LocalPosition, IrisDirection> doubled = Map.of(
+                socket, IrisDirection.NORTH_NEGATIVE_Z,
+                stray, IrisDirection.NORTH_NEGATIVE_Z);
+
+        Decision refused = JigsawStudioConnectorPlacement.decidePlanar(true, socket,
+                IrisDirection.NORTH_NEGATIVE_Z, dimensions, JigsawPlanarTopology.NORTH_END, single, "End Cap");
+        Decision removed = JigsawStudioConnectorPlacement.decidePlanar(true, stray,
+                IrisDirection.NORTH_NEGATIVE_Z, dimensions, JigsawPlanarTopology.NORTH_END, doubled, "End Cap");
+
+        assertEquals(Operation.REFUSE, refused.operation());
+        assertEquals(Operation.REMOVE, removed.operation());
+    }
+
+    @Test
+    public void framesRoundTripPositionsAndDirectionsForEveryQuarterTurn() {
+        JigsawStudioCellDimensions source = new JigsawStudioCellDimensions(6, 3, 4);
+        for (int quarterTurns = 0; quarterTurns < 4; quarterTurns++) {
+            Frame frame = new Frame(source, quarterTurns);
+            for (int x = 0; x < 6; x++) {
+                for (int z = 0; z < 4; z++) {
+                    IrisPosition position = new IrisPosition(x, 1, z);
+                    LocalPosition display = frame.display(position);
+                    JigsawStudioCellDimensions dimensions = frame.displayDimensions();
+                    assertTrue(display.x() >= 0 && display.x() < dimensions.width());
+                    assertTrue(display.z() >= 0 && display.z() < dimensions.depth());
+                    assertEquals(position, frame.source(display));
+                }
+            }
+            for (IrisDirection direction : IrisDirection.values()) {
+                assertEquals(direction, frame.sourceDirection(frame.displayDirection(direction)));
+            }
+        }
+    }
+
+    @Test
+    public void addConvertsDisplayPlacementIntoSourceSpaceWithDefaultIdentity() {
+        Frame frame = new Frame(new JigsawStudioCellDimensions(6, 3, 4), 1);
+        LocalPosition target = new LocalPosition(0, 1, 2);
+
+        List<IrisJigsawConnector> added = JigsawStudioConnectorPlacement.add(
+                List.of(), frame, target, IrisDirection.WEST_NEGATIVE_X, IrisDirection.UP_POSITIVE_Y, SPATIAL, EMPTY);
+
+        IrisJigsawConnector connector = added.getFirst();
+        assertEquals(target, frame.display(connector.getPosition()));
+        assertEquals(IrisDirection.WEST_NEGATIVE_X, frame.displayDirection(connector.getDirection()));
+        assertEquals(IrisDirection.UP_POSITIVE_Y, connector.getTop());
+        assertEquals("demo/pieces", connector.getPool());
+        assertEquals("iris:spatial", connector.getName());
+        assertEquals("iris:spatial", connector.getTargetName());
+        assertEquals(JigsawJoint.ROLLABLE, connector.getJoint());
+        assertEquals("minecraft:structure_void", connector.getFinalState());
+        assertEquals("", connector.getChannel());
+    }
+
+    @Test
+    public void connectorsPlacedOnBuiltBlocksKeepThatBlockAsTheirFinalState() {
+        Frame frame = new Frame(new JigsawStudioCellDimensions(5, 5, 5), 0);
+        CellContents wall = position -> Optional.of(new CellContent("minecraft:stone_bricks", false));
+        CellContents chest = position -> Optional.of(new CellContent("minecraft:chest[facing=north]", true));
+
+        List<IrisJigsawConnector> added = JigsawStudioConnectorPlacement.add(
+                List.of(), frame, new LocalPosition(2, 1, 0), IrisDirection.NORTH_NEGATIVE_Z,
+                IrisDirection.UP_POSITIVE_Y, SPATIAL, wall);
+
+        assertEquals("minecraft:stone_bricks", added.getFirst().getFinalState());
+        assertThrows(IllegalArgumentException.class, () -> JigsawStudioConnectorPlacement.add(
+                List.of(), frame, new LocalPosition(2, 1, 0), IrisDirection.NORTH_NEGATIVE_Z,
+                IrisDirection.UP_POSITIVE_Y, SPATIAL, chest));
+    }
+
+    @Test
+    public void addingOntoAnExistingConnectorIsRejected() {
+        Frame frame = new Frame(new JigsawStudioCellDimensions(5, 5, 5), 0);
+        List<IrisJigsawConnector> source = List.of(connector(new IrisPosition(2, 1, 0), IrisDirection.NORTH_NEGATIVE_Z));
+
+        assertThrows(IllegalArgumentException.class, () -> JigsawStudioConnectorPlacement.add(
+                source, frame, new LocalPosition(2, 1, 0), IrisDirection.NORTH_NEGATIVE_Z,
+                IrisDirection.UP_POSITIVE_Y, SPATIAL, EMPTY));
+    }
+
+    @Test
+    public void moveKeepsIdentityAndOrderAndOnlyReplacesTheFinalStateOnBuiltBlocks() {
+        Frame frame = new Frame(new JigsawStudioCellDimensions(5, 5, 5), 0);
+        IrisJigsawConnector first = connector(new IrisPosition(2, 1, 0), IrisDirection.NORTH_NEGATIVE_Z)
+                .setChannel("hall").setFinalState("minecraft:air");
+        IrisJigsawConnector second = connector(new IrisPosition(4, 1, 2), IrisDirection.EAST_POSITIVE_X);
+        List<IrisJigsawConnector> source = List.of(first, second);
+
+        List<IrisJigsawConnector> moved = JigsawStudioConnectorPlacement.move(
+                source, frame, new LocalPosition(2, 1, 0), new LocalPosition(0, 1, 2),
+                IrisDirection.WEST_NEGATIVE_X, IrisDirection.UP_POSITIVE_Y, EMPTY);
+        List<IrisJigsawConnector> onWall = JigsawStudioConnectorPlacement.move(
+                source, frame, new LocalPosition(2, 1, 0), new LocalPosition(0, 1, 2),
+                IrisDirection.WEST_NEGATIVE_X, IrisDirection.UP_POSITIVE_Y,
+                position -> Optional.of(new CellContent("minecraft:stone", false)));
+
+        assertEquals(2, moved.size());
+        assertEquals(new IrisPosition(0, 1, 2), moved.getFirst().getPosition());
+        assertEquals(IrisDirection.WEST_NEGATIVE_X, moved.getFirst().getDirection());
+        assertEquals("hall", moved.getFirst().getChannel());
+        assertEquals("demo/pieces", moved.getFirst().getPool());
+        assertEquals("minecraft:air", moved.getFirst().getFinalState());
+        assertEquals("minecraft:stone", onWall.getFirst().getFinalState());
+        assertEquals(second.getPosition(), moved.get(1).getPosition());
+        assertEquals(new IrisPosition(2, 1, 0), first.getPosition());
+        assertThrows(IllegalArgumentException.class, () -> JigsawStudioConnectorPlacement.move(
+                source, frame, new LocalPosition(2, 1, 0), new LocalPosition(4, 1, 2),
+                IrisDirection.EAST_POSITIVE_X, IrisDirection.UP_POSITIVE_Y, EMPTY));
+    }
+
+    @Test
+    public void removeDropsOnlyTheConnectorAtThatDisplayPosition() {
+        Frame frame = new Frame(new JigsawStudioCellDimensions(5, 5, 5), 2);
+        IrisJigsawConnector north = connector(new IrisPosition(2, 1, 0), IrisDirection.NORTH_NEGATIVE_Z);
+        IrisJigsawConnector east = connector(new IrisPosition(4, 1, 2), IrisDirection.EAST_POSITIVE_X);
+
+        List<IrisJigsawConnector> remaining = JigsawStudioConnectorPlacement.remove(
+                List.of(north, east), frame, frame.display(north.getPosition()));
+
+        assertEquals(1, remaining.size());
+        assertEquals(east.getPosition(), remaining.getFirst().getPosition());
+    }
+
+    @Test
+    public void reseatSnapsAMovedSocketBackToTheSourceFaceCenterAndDropsStrays() {
+        JigsawStudioCellDimensions source = new JigsawStudioCellDimensions(4, 4, 6);
+        Frame frame = new Frame(source, 1);
+        IrisJigsawConnector moved = connector(new IrisPosition(0, 1, 0), IrisDirection.NORTH_NEGATIVE_Z).setChannel("road");
+        IrisJigsawConnector stray = connector(new IrisPosition(3, 1, 0), IrisDirection.NORTH_NEGATIVE_Z);
+        IrisJigsawConnector south = connector(
+                IrisJigsawConnector.canonicalPlanarPosition(new IrisPosition(4, 4, 6), IrisDirection.SOUTH_POSITIVE_Z),
+                IrisDirection.SOUTH_POSITIVE_Z);
+        JigsawPlanarDirection displaySide = JigsawPlanarDirection.EAST;
+        assertEquals(IrisDirection.NORTH_NEGATIVE_Z, frame.sourceDirection(displaySide.irisDirection()));
+
+        ReseatResult result = JigsawStudioConnectorPlacement.reseat(
+                List.of(moved, stray, south), frame, displaySide, SPATIAL, EMPTY);
+
+        assertTrue(result.changed());
+        assertEquals(1, result.removedStrays());
+        assertEquals(2, result.connectors().size());
+        IrisJigsawConnector seated = result.connectors().getFirst();
+        assertEquals(IrisJigsawConnector.canonicalPlanarPosition(
+                new IrisPosition(4, 4, 6), IrisDirection.NORTH_NEGATIVE_Z), seated.getPosition());
+        assertEquals("road", seated.getChannel());
+        assertEquals(south.getPosition(), result.connectors().get(1).getPosition());
+
+        ReseatResult unchanged = JigsawStudioConnectorPlacement.reseat(
+                result.connectors(), frame, displaySide, SPATIAL, EMPTY);
+        assertFalse(unchanged.changed());
+    }
+
+    @Test
+    public void reseatAddsAMissingSocketWithTheDefaultIdentity() {
+        Frame frame = new Frame(new JigsawStudioCellDimensions(5, 5, 5), 0);
+        Identity planar = new Identity("demo/pieces", "iris:planar", "iris:planar", JigsawJoint.ALIGNED);
+
+        ReseatResult result = JigsawStudioConnectorPlacement.reseat(
+                List.of(), frame, JigsawPlanarDirection.WEST, planar, EMPTY);
+
+        assertTrue(result.changed());
+        IrisJigsawConnector added = result.connectors().getFirst();
+        assertEquals(new IrisPosition(0, 2, 2), added.getPosition());
+        assertEquals(IrisDirection.WEST_NEGATIVE_X, added.getDirection());
+        assertEquals(IrisDirection.UP_POSITIVE_Y, added.getTop());
+        assertEquals(JigsawJoint.ALIGNED, added.getJoint());
+        assertEquals("iris:planar", added.getName());
+    }
+
+    @Test
+    public void changedPositionsListEveryDisplayCellWhoseConnectorDiffers() {
+        Frame frame = new Frame(new JigsawStudioCellDimensions(5, 5, 5), 0);
+        IrisJigsawConnector north = connector(new IrisPosition(2, 1, 0), IrisDirection.NORTH_NEGATIVE_Z);
+        IrisJigsawConnector east = connector(new IrisPosition(4, 1, 2), IrisDirection.EAST_POSITIVE_X);
+        List<IrisJigsawConnector> before = List.of(north, east);
+        List<IrisJigsawConnector> after = JigsawStudioConnectorPlacement.move(
+                before, frame, new LocalPosition(2, 1, 0), new LocalPosition(0, 1, 2),
+                IrisDirection.WEST_NEGATIVE_X, IrisDirection.UP_POSITIVE_Y, EMPTY);
+
+        Set<LocalPosition> changed = JigsawStudioConnectorPlacement.changedPositions(before, after, frame);
+
+        assertEquals(Set.of(new LocalPosition(2, 1, 0), new LocalPosition(0, 1, 2)), changed);
+    }
+
+    private static Operation spatial(
+            boolean primary,
+            LocalPosition target,
+            IrisDirection facing,
+            Map<LocalPosition, IrisDirection> connectors,
+            LocalPosition selection
+    ) {
+        return JigsawStudioConnectorPlacement.decideSpatial(
+                primary, target, facing, new LinkedHashMap<>(connectors), Optional.ofNullable(selection)).operation();
+    }
+
+    private static IrisJigsawConnector connector(IrisPosition position, IrisDirection direction) {
+        return new IrisJigsawConnector()
+                .setPosition(position)
+                .setDirection(direction)
+                .setTop(IrisDirection.UP_POSITIVE_Y)
+                .setPool("demo/pieces")
+                .setName("iris:spatial")
+                .setTargetName("iris:spatial")
+                .setJoint(JigsawJoint.ROLLABLE)
+                .setFinalState("minecraft:structure_void");
+    }
+}

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioConnectorRepairTest.java

@@ -0,0 +1,40 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.studio.jigsaw.JigsawStudioCapture.LocalPosition;
+import org.bukkit.Material;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.junit.Test;
+
+import java.util.Set;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class JigsawStudioConnectorRepairTest {
+    @Test
+    public void resetFindsUnsavedMarkersSoTopologyErrorsCanBeRepaired() {
+        JigsawStudioBounds bounds = new JigsawStudioBounds(0, 65, 0, new JigsawStudioCellDimensions(3, 2, 3));
+        World world = mock(World.class);
+        Block air = mock(Block.class);
+        when(air.getType()).thenReturn(Material.AIR);
+        Block saved = mock(Block.class);
+        when(saved.getType()).thenReturn(Material.JIGSAW);
+        Block stray = mock(Block.class);
+        when(stray.getType()).thenReturn(Material.JIGSAW);
+        when(world.getBlockAt(anyInt(), anyInt(), anyInt())).thenReturn(air);
+        when(world.getBlockAt(1, 65, 0)).thenReturn(saved);
+        when(world.getBlockAt(1, 66, 1)).thenReturn(stray);
+        JigsawStudioCapture.ChunkCaptureArea area = JigsawStudioCapture.chunkIntersections(bounds).getFirst();
+        Set<LocalPosition> savedConnectors = Set.of(new LocalPosition(1, 0, 0));
+
+        assertEquals(
+                Set.of(new LocalPosition(1, 1, 1)),
+                JigsawStudioMaterializer.strayMarkerPositions(world, bounds, area, savedConnectors, true));
+        assertEquals(
+                Set.of(new LocalPosition(1, 0, 0), new LocalPosition(1, 1, 1)),
+                JigsawStudioMaterializer.strayMarkerPositions(world, bounds, area, savedConnectors, false));
+    }
+}

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioEditorRoutingTest.java

@@ -0,0 +1,143 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.iris.pack.loading.IrisData;
+import art.arcane.iris.studio.generation.JigsawStudioGenerator;
+import art.arcane.iris.world.task.J;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockFace;
+import org.bukkit.entity.Player;
+import org.bukkit.event.block.BlockPistonExtendEvent;
+import org.junit.Test;
+import org.mockito.MockedStatic;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class JigsawStudioEditorRoutingTest {
+    private static final UUID REQUEST = UUID.fromString("66666666-6666-6666-6666-666666666666");
+
+    @Test
+    public void renamingASpatialWorkcellRenamesTheVariantThatLabelsIt() throws Exception {
+        JigsawStudioVariant variant = new JigsawStudioVariant(
+                "demo/cross",
+                "demo/cross",
+                "",
+                Optional.of(new JigsawStudioCellDimensions(15, 15, 15)),
+                JigsawStudioMode.SPATIAL_JIGSAW,
+                Optional.empty(),
+                true,
+                true,
+                List.of(),
+                new JigsawStudioPieceRules(0, 30, 0, 0, false),
+                List.of());
+        JigsawStudioLayout layout = JigsawStudioLayout.create(
+                JigsawStudioMode.SPATIAL_JIGSAW,
+                new JigsawStudioCellDimensions(15, 15, 15),
+                new JigsawStudioVariantCatalog(List.of(variant)));
+        JigsawStudioSession session = new JigsawStudioSession(REQUEST, "overworld", "demo", layout);
+        JigsawStudioService service = new JigsawStudioService();
+        JigsawStudioVariantProperties properties = mock(JigsawStudioVariantProperties.class);
+        setField(service, "variantProperties", properties);
+        Player player = register(service, session);
+
+        try (MockedStatic<J> scheduling = mockStatic(J.class)) {
+            scheduling.when(() -> J.isOwnedByCurrentRegion(any(Player.class))).thenReturn(true);
+
+            service.workcellEditor.updateWorkcellDisplayName(player, JigsawStudioLayout.SPATIAL_WORKCELL_ID, "Great Hall");
+
+            verify(properties).updateVariantDisplayName(
+                    player, JigsawStudioLayout.SPATIAL_WORKCELL_ID, "demo/cross", "Great Hall");
+        }
+    }
+
+    @Test
+    public void pistonHeadsCannotExtendIntoProtectedStudioCells() throws Exception {
+        JigsawStudioService service = new JigsawStudioService();
+        JigsawStudioProtection protection = mock(JigsawStudioProtection.class);
+        setField(service, "protection", protection);
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(UUID.randomUUID());
+        Block piston = mock(Block.class);
+        Block head = mock(Block.class);
+        when(piston.getWorld()).thenReturn(world);
+        when(piston.getRelative(BlockFace.EAST)).thenReturn(head);
+        when(protection.isImmutableStudioBlock(head)).thenReturn(true);
+        BlockPistonExtendEvent event = new BlockPistonExtendEvent(piston, List.of(), BlockFace.EAST);
+
+        service.protectionListener.onProtectedPistonExtend(event);
+
+        assertTrue(event.isCancelled());
+    }
+
+    private static Player register(JigsawStudioService service, JigsawStudioSession session) throws Exception {
+        UUID worldId = UUID.randomUUID();
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(worldId);
+        Player player = mock(Player.class);
+        when(player.getWorld()).thenReturn(world);
+        when(player.getUniqueId()).thenReturn(UUID.randomUUID());
+        JigsawStudioActivation.Request request = new JigsawStudioActivation.Request(
+                REQUEST,
+                "overworld",
+                "demo",
+                JigsawStudioMode.SPATIAL_JIGSAW,
+                JigsawStudioCompatibilityTarget.IRIS_EXTENDED,
+                new JigsawStudioCellDimensions(15, 15, 15),
+                mock(IrisData.class),
+                null);
+        JigsawStudioGenerator generator = mock(JigsawStudioGenerator.class);
+        when(generator.getRequest()).thenReturn(request);
+        when(generator.getSession()).thenReturn(session);
+        when(generator.getLayout()).thenAnswer(invocation -> session.layout());
+        Class<?> studioType = Class.forName(JigsawStudioService.class.getName() + "$ActiveStudio");
+        Constructor<?> constructor = studioType.getDeclaredConstructor(
+                UUID.class,
+                World.class,
+                Engine.class,
+                JigsawStudioGenerator.class,
+                ConcurrentHashMap.class,
+                Set.class,
+                AtomicLong.class);
+        constructor.setAccessible(true);
+        Object studio = constructor.newInstance(
+                worldId,
+                world,
+                mock(Engine.class),
+                generator,
+                new ConcurrentHashMap<>(),
+                ConcurrentHashMap.newKeySet(),
+                new AtomicLong());
+        @SuppressWarnings("unchecked")
+        Map<UUID, Object> studios = (Map<UUID, Object>) getField(service, "studios");
+        studios.put(worldId, studio);
+        return player;
+    }
+
+    private static void setField(Object target, String name, Object value) throws Exception {
+        Field field = target.getClass().getDeclaredField(name);
+        field.setAccessible(true);
+        field.set(target, value);
+    }
+
+    private static Object getField(Object target, String name) throws Exception {
+        Field field = target.getClass().getDeclaredField(name);
+        field.setAccessible(true);
+        return field.get(target);
+    }
+}

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioFloorGlyphTest.java

@@ -0,0 +1,139 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.pack.value.IrisDirection;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.Assert.assertEquals;
+
+public class JigsawStudioFloorGlyphTest {
+    @Test
+    public void emptyConnectorListPaintsOnlyTheBase() {
+        JigsawStudioFloorGlyph glyph = JigsawStudioFloorGlyph.of(5, 5, List.of());
+
+        assertRows(glyph, 5, 5, List.of(".....", ".....", ".....", ".....", "....."));
+    }
+
+    @Test
+    public void canonicalPlanarSocketsDrawStraightLinesFromTheCenter() {
+        Map<JigsawPlanarArchetype, List<String>> expected = Map.of(
+                JigsawPlanarArchetype.END, List.of("..o..", "..#..", "..#..", ".....", "....."),
+                JigsawPlanarArchetype.STRAIGHT, List.of("..o..", "..#..", "..#..", "..#..", "..o.."),
+                JigsawPlanarArchetype.CORNER, List.of("..o..", "..#..", "..##o", ".....", "....."),
+                JigsawPlanarArchetype.TEE, List.of("..o..", "..#..", "o###o", ".....", "....."),
+                JigsawPlanarArchetype.CROSS, List.of("..o..", "..#..", "o###o", "..#..", "..o.."));
+
+        for (Map.Entry<JigsawPlanarArchetype, List<String>> entry : expected.entrySet()) {
+            List<JigsawStudioFloorGlyph.Marker> markers = new ArrayList<>();
+            for (JigsawPlanarDirection direction : entry.getKey().canonicalTopology().directions()) {
+                markers.add(canonicalMarker(5, 5, direction.irisDirection()));
+            }
+            assertRows(JigsawStudioFloorGlyph.of(5, 5, markers), 5, 5, entry.getValue());
+        }
+    }
+
+    @Test
+    public void evenFootprintsUseFloorDivisionForTheCenter() {
+        JigsawStudioFloorGlyph glyph = JigsawStudioFloorGlyph.of(4, 4, List.of(
+                canonicalMarker(4, 4, IrisDirection.NORTH_NEGATIVE_Z),
+                canonicalMarker(4, 4, IrisDirection.WEST_NEGATIVE_X)));
+
+        assertRows(glyph, 4, 4, List.of("..o.", "..#.", "o##.", "...."));
+    }
+
+    @Test
+    public void verticalConnectorsUseDistinctSocketsAndMergeOnOneColumn() {
+        JigsawStudioFloorGlyph up = JigsawStudioFloorGlyph.of(5, 5, List.of(
+                new JigsawStudioFloorGlyph.Marker(2, 2, IrisDirection.UP_POSITIVE_Y)));
+        JigsawStudioFloorGlyph down = JigsawStudioFloorGlyph.of(5, 5, List.of(
+                new JigsawStudioFloorGlyph.Marker(2, 2, IrisDirection.DOWN_NEGATIVE_Y)));
+        JigsawStudioFloorGlyph both = JigsawStudioFloorGlyph.of(5, 5, List.of(
+                new JigsawStudioFloorGlyph.Marker(2, 2, IrisDirection.UP_POSITIVE_Y),
+                new JigsawStudioFloorGlyph.Marker(2, 2, IrisDirection.DOWN_NEGATIVE_Y),
+                canonicalMarker(5, 5, IrisDirection.EAST_POSITIVE_X)));
+
+        assertEquals(JigsawStudioFloorGlyph.Cell.UP_SOCKET, up.cell(2, 2));
+        assertEquals(JigsawStudioFloorGlyph.Cell.DOWN_SOCKET, down.cell(2, 2));
+        assertRows(both, 5, 5, List.of(".....", ".....", "..B#o", ".....", "....."));
+    }
+
+    @Test
+    public void offCenterVerticalConnectorsGetALineToTheirColumn() {
+        JigsawStudioFloorGlyph glyph = JigsawStudioFloorGlyph.of(5, 5, List.of(
+                new JigsawStudioFloorGlyph.Marker(0, 2, IrisDirection.DOWN_NEGATIVE_Y)));
+
+        assertRows(glyph, 5, 5, List.of(".....", ".....", "v##..", ".....", "....."));
+    }
+
+    @Test
+    public void interiorHorizontalConnectorsExtendTheirLineOutOfTheFaceTheyOpen() {
+        JigsawStudioFloorGlyph glyph = JigsawStudioFloorGlyph.of(5, 5, List.of(
+                new JigsawStudioFloorGlyph.Marker(3, 2, IrisDirection.SOUTH_POSITIVE_Z)));
+
+        assertRows(glyph, 5, 5, List.of(".....", ".....", "..#o.", "...#.", "...#."));
+    }
+
+    @Test
+    public void diagonalLinesStayConnectedAndInsideTheFootprint() {
+        JigsawStudioFloorGlyph glyph = JigsawStudioFloorGlyph.of(7, 5, List.of(
+                new JigsawStudioFloorGlyph.Marker(6, 0, IrisDirection.EAST_POSITIVE_X)));
+
+        assertEquals(JigsawStudioFloorGlyph.Cell.HORIZONTAL_SOCKET, glyph.cell(6, 0));
+        assertEquals(JigsawStudioFloorGlyph.Cell.LINE, glyph.cell(3, 2));
+        int lineCells = 0;
+        for (int z = 0; z < 5; z++) {
+            for (int x = 0; x < 7; x++) {
+                if (glyph.cell(x, z) == JigsawStudioFloorGlyph.Cell.LINE) {
+                    lineCells++;
+                }
+            }
+        }
+        assertEquals(3, lineCells);
+        assertEquals(JigsawStudioFloorGlyph.Cell.BASE, glyph.cell(-1, 0));
+        assertEquals(JigsawStudioFloorGlyph.Cell.BASE, glyph.cell(7, 0));
+    }
+
+    @Test
+    public void markersOutsideTheFootprintAreClampedToItsEdge() {
+        JigsawStudioFloorGlyph glyph = JigsawStudioFloorGlyph.of(3, 3, List.of(
+                new JigsawStudioFloorGlyph.Marker(9, 1, IrisDirection.EAST_POSITIVE_X)));
+
+        assertRows(glyph, 3, 3, List.of("...", ".#o", "..."));
+    }
+
+    private static JigsawStudioFloorGlyph.Marker canonicalMarker(int width, int depth, IrisDirection direction) {
+        int centerX = width / 2;
+        int centerZ = depth / 2;
+        return switch (direction) {
+            case NORTH_NEGATIVE_Z -> new JigsawStudioFloorGlyph.Marker(centerX, 0, direction);
+            case SOUTH_POSITIVE_Z -> new JigsawStudioFloorGlyph.Marker(centerX, depth - 1, direction);
+            case EAST_POSITIVE_X -> new JigsawStudioFloorGlyph.Marker(width - 1, centerZ, direction);
+            case WEST_NEGATIVE_X -> new JigsawStudioFloorGlyph.Marker(0, centerZ, direction);
+            case UP_POSITIVE_Y, DOWN_NEGATIVE_Y -> new JigsawStudioFloorGlyph.Marker(centerX, centerZ, direction);
+        };
+    }
+
+    private static void assertRows(JigsawStudioFloorGlyph glyph, int width, int depth, List<String> rows) {
+        for (int z = 0; z < depth; z++) {
+            StringBuilder actual = new StringBuilder(width);
+            for (int x = 0; x < width; x++) {
+                actual.append(symbol(glyph.cell(x, z)));
+            }
+            assertEquals("row " + z, rows.get(z), actual.toString());
+        }
+    }
+
+    private static char symbol(JigsawStudioFloorGlyph.Cell cell) {
+        return switch (cell) {
+            case BASE -> '.';
+            case LINE -> '#';
+            case HORIZONTAL_SOCKET -> 'o';
+            case UP_SOCKET -> '^';
+            case DOWN_SOCKET -> 'v';
+            case UP_AND_DOWN_SOCKET -> 'B';
+        };
+    }
+}

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioGraphMapperTest.java

@@ -234,6 +234,60 @@ public class JigsawStudioGraphMapperTest {
         assertEquals(new JigsawStudioCellDimensions(24, 32, 24), dimensions);
     }
 
+    @Test
+    @SuppressWarnings("unchecked")
+    public void spatialFootprintRejectsChangesThatExceedTheWorkcellVolume() {
+        IrisData data = mock(IrisData.class);
+        ResourceLoader<IrisObject> objectLoader = mock(ResourceLoader.class);
+        when(data.getObjectLoader()).thenReturn(objectLoader);
+        when(objectLoader.load("stronghold/tower")).thenReturn(new IrisObject(16, 192, 16));
+        when(objectLoader.load("stronghold/hall")).thenReturn(new IrisObject(128, 10, 20));
+        JigsawStudioVariantCatalog catalog = new JigsawStudioVariantCatalog(List.of(
+                spatialVariant("stronghold/tower", new JigsawStudioCellDimensions(16, 192, 16), false),
+                spatialVariant("stronghold/hall", new JigsawStudioCellDimensions(128, 10, 20), false)));
+        JigsawStudioCellDimensions configured = new JigsawStudioCellDimensions(16, 16, 16);
+
+        assertEquals("", JigsawStudioGraphMapper.spatialFootprintFailure(
+                data,
+                configured,
+                catalog,
+                new JigsawStudioGraphMapper.SpatialChange("stronghold/hall", new JigsawStudioCellDimensions(128, 10, 20), false)));
+        assertFalse(JigsawStudioGraphMapper.spatialFootprintFailure(
+                data,
+                configured,
+                catalog,
+                new JigsawStudioGraphMapper.SpatialChange("stronghold/hall", new JigsawStudioCellDimensions(128, 10, 20), true)).isEmpty());
+        assertFalse(JigsawStudioGraphMapper.spatialFootprintFailure(
+                data,
+                configured,
+                catalog,
+                new JigsawStudioGraphMapper.SpatialChange("stronghold/hall", new JigsawStudioCellDimensions(128, 10, 128), false)).isEmpty());
+        assertEquals("", JigsawStudioGraphMapper.spatialFootprintFailure(
+                data,
+                configured,
+                catalog,
+                new JigsawStudioGraphMapper.SpatialChange("stronghold/tower", new JigsawStudioCellDimensions(16, 64, 16), false)));
+    }
+
+    private static JigsawStudioVariant spatialVariant(
+            String key,
+            JigsawStudioCellDimensions dimensions,
+            boolean rotatable
+    ) {
+        return new JigsawStudioVariant(
+                key,
+                key,
+                "",
+                Optional.of(dimensions),
+                JigsawStudioMode.SPATIAL_JIGSAW,
+                Optional.empty(),
+                rotatable,
+                true,
+                List.of(),
+                new JigsawStudioPieceRules(0, 30, 0, 0, false),
+                List.of());
+    }
+
     @Test
     @SuppressWarnings("unchecked")
     public void mapsAuthorLabelsAndCanonicalPerVariantDimensionsIndependently() {

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioLayoutColumnTest.java

@@ -0,0 +1,27 @@
+package art.arcane.iris.studio.jigsaw;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+
+public class JigsawStudioLayoutColumnTest {
+    @Test
+    public void columnLookupFocusesTheWorkcellFromItsFloorToTheTeleportHeight() {
+        JigsawStudioLayout layout = JigsawStudioLayout.create(
+                JigsawStudioMode.PLANAR_JIGSAW,
+                new JigsawStudioCellDimensions(7, 5, 7),
+                JigsawStudioVariantCatalog.empty());
+        JigsawStudioBay cross = layout.get("workcell/cross");
+        JigsawStudioBounds bounds = cross.bounds();
+        int x = bounds.originX() + 3;
+        int z = bounds.originZ() + 3;
+
+        assertSame(cross, layout.findColumn(x, bounds.originY() - 1, z));
+        assertSame(cross, layout.findColumn(x, bounds.maxY() + 2, z));
+        assertSame(cross, layout.findColumn(x, bounds.maxY() + JigsawStudioLayout.COLUMN_HEADROOM, z));
+        assertNull(layout.findColumn(x, bounds.maxY() + JigsawStudioLayout.COLUMN_HEADROOM + 1, z));
+        assertNull(layout.findColumn(bounds.originX() - 1, bounds.originY(), z));
+        assertNull(layout.findAt(x, bounds.maxY() + 2, z));
+    }
+}

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioMainMenuRowTest.java

@@ -0,0 +1,47 @@
+package art.arcane.iris.studio.jigsaw;
+
+import org.junit.Test;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class JigsawStudioMainMenuRowTest {
+    @Test
+    public void planarRowKeepsAllSixWorkcellsLeftOfTheRowControls() {
+        JigsawStudioMainMenu.WorkcellRow row = JigsawStudioMainMenu.workcellRow(6, 4);
+
+        assertEquals(List.of(0, 1, 2, 3, 4, 5), row.indices());
+        assertEquals(List.of(-3, -2, -1, 0, 1, 2), row.slots());
+        assertEquals(-1, row.previousTarget());
+        assertEquals(-1, row.nextTarget());
+    }
+
+    @Test
+    public void largeSpatialRowsPageWithoutHidingOrOverlappingWorkcells() {
+        for (int count : new int[]{7, 24}) {
+            Set<Integer> reachable = new HashSet<>();
+            for (int viewed = 0; viewed < count; viewed++) {
+                JigsawStudioMainMenu.WorkcellRow row = JigsawStudioMainMenu.workcellRow(count, viewed);
+                assertTrue(row.indices().contains(viewed));
+                assertEquals(row.indices().size(), new HashSet<>(row.slots()).size());
+                for (int slot : row.slots()) {
+                    assertTrue(slot >= -3 && slot <= 1);
+                }
+                reachable.addAll(row.indices());
+                if (row.nextTarget() >= 0) {
+                    assertTrue(JigsawStudioMainMenu.workcellRow(count, row.nextTarget()).indices()
+                            .contains(row.nextTarget()));
+                }
+            }
+            assertEquals(count, reachable.size());
+        }
+        JigsawStudioMainMenu.WorkcellRow last = JigsawStudioMainMenu.workcellRow(24, 23);
+        assertEquals(List.of(20, 21, 22, 23), last.indices());
+        assertEquals(15, last.previousTarget());
+        assertEquals(-1, last.nextTarget());
+    }
+}

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioPersistenceEditorsTest.java

@@ -491,7 +491,7 @@ public class JigsawStudioPersistenceEditorsTest {
         JigsawStudioGraphEditor.VariantFamilyCreation creation = JigsawStudioGraphEditor.duplicateActiveFamily(
                 packRoot,
                 "studio/spatial",
-                Map.of(JigsawStudioLayout.SPATIAL_WORKCELL_ID, "studio/spatial/start"),
+                Map.of(JigsawStudioLayout.SPATIAL_WORKCELL_ID, "studio/spatial/blank"),
                 "variant-2");
 
         assertTrue(creation.writeResult().successful());
@@ -499,7 +499,7 @@ public class JigsawStudioPersistenceEditorsTest {
                 "studio/spatial/variants/spatial/variant-2",
                 creation.pieceKeysByWorkcell().get(JigsawStudioLayout.SPATIAL_WORKCELL_ID));
         JsonObject pool = readJson(packRoot.resolve("jigsaw-pools/studio/spatial/start.json"));
-        assertEquals(8, pool.getAsJsonArray("pieces").size());
+        assertEquals(25, pool.getAsJsonArray("pieces").size());
     }
 
     @Test
@@ -507,10 +507,13 @@ public class JigsawStudioPersistenceEditorsTest {
         Path packRoot = createSpatialProject("spatial-theme-row");
 
         Map<String, String> sources = new LinkedHashMap<>();
-        sources.put(JigsawStudioLayout.SPATIAL_WORKCELL_ID, "studio/spatial/start");
+        for (String vertical : List.of("", "-up", "-down", "-up-down")) {
-        for (int connectorCount = 1; connectorCount <= 6; connectorCount++) {
+            for (String horizontal : List.of("blank", "end", "straight", "corner", "tee", "cross")) {
-            String pieceKey = "studio/spatial/connectors-" + connectorCount;
+                String pieceKey = "studio/spatial/" + horizontal + vertical;
-            sources.put(JigsawStudioLayout.SPATIAL_WORKCELL_ID + "/" + pieceKey, pieceKey);
+                sources.put(sources.isEmpty()
+                        ? JigsawStudioLayout.SPATIAL_WORKCELL_ID
+                        : JigsawStudioLayout.SPATIAL_WORKCELL_ID + "/" + pieceKey, pieceKey);
+            }
         }
         JigsawStudioGraphEditor.VariantFamilyCreation creation = JigsawStudioGraphEditor.duplicateActiveFamily(
                 packRoot,
@@ -519,13 +522,13 @@ public class JigsawStudioPersistenceEditorsTest {
                 "variant-2");
 
         assertTrue(creation.writeResult().successful());
-        assertEquals(7, creation.pieceKeysByWorkcell().size());
+        assertEquals(24, creation.pieceKeysByWorkcell().size());
         for (String targetPieceKey : creation.pieceKeysByWorkcell().values()) {
             assertTrue(Files.isRegularFile(packRoot.resolve("jigsaw-pieces/" + targetPieceKey + ".json")));
             assertTrue(Files.isRegularFile(packRoot.resolve("objects/" + targetPieceKey + ".iob")));
         }
         JsonObject pool = readJson(packRoot.resolve("jigsaw-pools/studio/spatial/start.json"));
-        assertEquals(14, pool.getAsJsonArray("pieces").size());
+        assertEquals(48, pool.getAsJsonArray("pieces").size());
     }
 
     @Test
@@ -557,7 +560,7 @@ public class JigsawStudioPersistenceEditorsTest {
                 "END").get("displayName").getAsString());
 
         Path spatialRoot = createSpatialProject("labels-spatial");
-        Path spatialObject = spatialRoot.resolve("objects/studio/spatial/start.iob");
+        Path spatialObject = spatialRoot.resolve("objects/studio/spatial/blank.iob");
         byte[] spatialBefore = Files.readAllBytes(spatialObject);
 
         assertTrue(JigsawStudioStructureEditor.updateSpatialWorkcellDisplayName(

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioPersistenceIdentityTest.java

@@ -34,7 +34,7 @@ public class JigsawStudioPersistenceIdentityTest {
     private static final String PIECE_POOL_KEY = "studio/identity/pieces";
     private static final String RECORDED_AT_FIELD = "recordedAtEpochMilli";
     private static final String SCRIPTED_SESSION_DIGEST =
-            "318d9338a63a44063c85e59a9e74f869473d6e0f15c362536172f7723d960faa";
+            "42b5d3bed8d74b2ef7a010a58302544d0d425c83faba0dc86efb0e41e69ba627";
 
     @Rule
     public final TemporaryFolder temporaryFolder = new TemporaryFolder();

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioProjectCreatorTest.java

@@ -102,9 +102,15 @@ public class JigsawStudioProjectCreatorTest {
         JsonObject startPool = JsonParser.parseString(Files.readString(
                 temporaryDirectory.resolve("jigsaw-pools/settlement/test/start.json"),
                 StandardCharsets.UTF_8)).getAsJsonObject();
-        assertEquals(1, startPool.getAsJsonArray("pieces").size());
+        assertEquals(2, startPool.getAsJsonArray("pieces").size());
         assertEquals("settlement/test/cross", startPool.getAsJsonArray("pieces").get(0)
                 .getAsJsonObject().get("piece").getAsString());
+        assertEquals(3, startPool.getAsJsonArray("pieces").get(0)
+                .getAsJsonObject().get("weight").getAsInt());
+        assertEquals("settlement/test/blank", startPool.getAsJsonArray("pieces").get(1)
+                .getAsJsonObject().get("piece").getAsString());
+        assertEquals(1, startPool.getAsJsonArray("pieces").get(1)
+                .getAsJsonObject().get("weight").getAsInt());
         JsonObject piecePool = JsonParser.parseString(Files.readString(
                 temporaryDirectory.resolve("jigsaw-pools/settlement/test/pieces.json"),
                 StandardCharsets.UTF_8)).getAsJsonObject();
@@ -229,7 +235,7 @@ public class JigsawStudioProjectCreatorTest {
     }
 
     @Test
-    public void spatialProjectSeedsZeroThroughSixConnectorVariants() throws Exception {
+    public void spatialProjectSeedsEveryYRotationTopologyVariant() throws Exception {
         Path temporaryDirectory = temporaryFolder.getRoot().toPath();
         JigsawStudioProjectCreator.Options options = new JigsawStudioProjectCreator.Options(
                 "stronghold/gallery",
@@ -246,35 +252,48 @@ public class JigsawStudioProjectCreatorTest {
         JsonObject piecePool = JsonParser.parseString(Files.readString(
                 temporaryDirectory.resolve("jigsaw-pools/stronghold/gallery/pieces.json"),
                 StandardCharsets.UTF_8)).getAsJsonObject();
-        assertEquals(7, startPool.getAsJsonArray("pieces").size());
+        assertEquals(24, startPool.getAsJsonArray("pieces").size());
-        assertEquals(7, piecePool.getAsJsonArray("pieces").size());
+        assertEquals("stronghold/gallery/blank", startPool.getAsJsonArray("pieces").get(0)
-        assertEquals("stronghold/gallery/connectors-1", piecePool.getAsJsonArray("pieces").get(0)
                 .getAsJsonObject().get("piece").getAsString());
-        assertTrue(piecePool.getAsJsonArray("pieces").get(6).getAsJsonObject()
+        assertEquals(24, piecePool.getAsJsonArray("pieces").size());
+        assertEquals("stronghold/gallery/end", piecePool.getAsJsonArray("pieces").get(0)
+                .getAsJsonObject().get("piece").getAsString());
+        assertTrue(piecePool.getAsJsonArray("pieces").get(23).getAsJsonObject()
                 .get("empty").getAsBoolean());
-        for (int connectorCount = 0; connectorCount <= 6; connectorCount++) {
+        List<String> horizontalClasses = List.of("blank", "end", "straight", "corner", "tee", "cross");
-            String pieceName = connectorCount == 0 ? "start" : "connectors-" + connectorCount;
+        List<String> verticalClasses = List.of("", "-up", "-down", "-up-down");
-            JsonObject piece = JsonParser.parseString(Files.readString(
+        List<Integer> horizontalCounts = List.of(0, 1, 2, 2, 3, 4);
-                    temporaryDirectory.resolve("jigsaw-pieces/stronghold/gallery/"
+        for (String vertical : verticalClasses) {
-                            + pieceName + ".json"),
+            for (int index = 0; index < horizontalClasses.size(); index++) {
-                    StandardCharsets.UTF_8)).getAsJsonObject();
+                String pieceName = horizontalClasses.get(index) + vertical;
-            assertEquals(connectorCount, piece.getAsJsonArray("connectors").size());
+                JsonObject piece = JsonParser.parseString(Files.readString(
-            assertEquals(connectorCount + (connectorCount == 1 ? " Connector" : " Connectors"),
+                        temporaryDirectory.resolve("jigsaw-pieces/stronghold/gallery/" + pieceName + ".json"),
-                    piece.get("displayName").getAsString());
+                        StandardCharsets.UTF_8)).getAsJsonObject();
-            assertEquals(16, piece.getAsJsonObject("rules").get("maximumPlacements").getAsInt());
+                int verticalCount = vertical.isEmpty() ? 0 : vertical.equals("-up-down") ? 2 : 1;
-            assertEquals(new IrisBlockVector(15, 15, 15), IrisObject.sampleSize(
+                assertEquals(pieceName, horizontalCounts.get(index) + verticalCount,
-                    temporaryDirectory.resolve("objects/stronghold/gallery/"
+                        piece.getAsJsonArray("connectors").size());
-                            + pieceName + ".iob").toFile()));
+                assertEquals(4, piece.getAsJsonObject("rules").get("maximumPlacements").getAsInt());
+                assertEquals(new IrisBlockVector(15, 15, 15), IrisObject.sampleSize(
+                        temporaryDirectory.resolve("objects/stronghold/gallery/"
+                                + pieceName + ".iob").toFile()));
+            }
         }
-        JsonObject six = JsonParser.parseString(Files.readString(
+        JsonObject cornerShaft = JsonParser.parseString(Files.readString(
-                temporaryDirectory.resolve("jigsaw-pieces/stronghold/gallery/connectors-6.json"),
+                temporaryDirectory.resolve("jigsaw-pieces/stronghold/gallery/corner-up-down.json"),
                 StandardCharsets.UTF_8)).getAsJsonObject();
-        assertEquals("NORTH_NEGATIVE_Z", six.getAsJsonArray("connectors").get(0)
+        assertEquals("L Junction + Up/Down", cornerShaft.get("displayName").getAsString());
+        assertEquals("NORTH_NEGATIVE_Z", cornerShaft.getAsJsonArray("connectors").get(0)
                 .getAsJsonObject().get("direction").getAsString());
-        assertEquals("DOWN_NEGATIVE_Y", six.getAsJsonArray("connectors").get(5)
+        assertEquals("EAST_POSITIVE_X", cornerShaft.getAsJsonArray("connectors").get(1)
                 .getAsJsonObject().get("direction").getAsString());
-        assertEquals(0, six.getAsJsonArray("connectors").get(5)
+        assertEquals("UP_POSITIVE_Y", cornerShaft.getAsJsonArray("connectors").get(2)
+                .getAsJsonObject().get("direction").getAsString());
+        assertEquals("DOWN_NEGATIVE_Y", cornerShaft.getAsJsonArray("connectors").get(3)
+                .getAsJsonObject().get("direction").getAsString());
+        assertEquals(0, cornerShaft.getAsJsonArray("connectors").get(3)
                 .getAsJsonObject().getAsJsonObject("position").get("y").getAsInt());
+        assertEquals("NORTH_NEGATIVE_Z", cornerShaft.getAsJsonArray("connectors").get(3)
+                .getAsJsonObject().get("top").getAsString());
 
         StructureGraphCompilation compilation = StructureResourceBundleGraphCompiler.compile(
                 JigsawStudioProjectCreator.bundle(options)).getFirst();
@@ -283,7 +302,7 @@ public class JigsawStudioProjectCreatorTest {
                 new IrisPosition(0, 0, 0)).assemble(new RNG(1337L));
         assertEquals(preview.detail(), StructureAssemblyStatus.COMPLETE, preview.status());
         assertTrue(preview.pieces().size() > 1);
-        assertTrue(preview.pieces().size() <= 96);
+        assertTrue(preview.pieces().size() <= 93);
     }
 
     @Test
@@ -411,10 +430,10 @@ public class JigsawStudioProjectCreatorTest {
         JsonObject pool = JsonParser.parseString(Files.readString(
                 temporaryDirectory.resolve("jigsaw-pools/stronghold/test/start.json"),
                 StandardCharsets.UTF_8)).getAsJsonObject();
-        assertEquals(8, pool.getAsJsonArray("pieces").size());
+        assertEquals(25, pool.getAsJsonArray("pieces").size());
-        assertEquals("stronghold/test/hall", pool.getAsJsonArray("pieces").get(7)
+        assertEquals("stronghold/test/hall", pool.getAsJsonArray("pieces").get(24)
                 .getAsJsonObject().get("piece").getAsString());
-        assertEquals(3, pool.getAsJsonArray("pieces").get(7)
+        assertEquals(3, pool.getAsJsonArray("pieces").get(24)
                 .getAsJsonObject().get("weight").getAsInt());
 
         StructureWriteResult resized = JigsawStudioStructureEditor.updateCellSize(
@@ -435,7 +454,7 @@ public class JigsawStudioProjectCreatorTest {
         IrisBlockVector hallSize = IrisObject.sampleSize(
                 temporaryDirectory.resolve("objects/stronghold/test/hall.iob").toFile());
         IrisBlockVector starterSize = IrisObject.sampleSize(
-                temporaryDirectory.resolve("objects/stronghold/test/start.iob").toFile());
+                temporaryDirectory.resolve("objects/stronghold/test/blank.iob").toFile());
         assertEquals(new IrisBlockVector(16, 12, 18), hallSize);
         assertEquals(new IrisBlockVector(12, 10, 14), starterSize);
 

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioProtectionProbeTest.java

@@ -56,6 +56,21 @@ public class JigsawStudioProtectionProbeTest {
         }
     }
 
+    @Test
+    public void protectedWorkcellProbesAreDeniedWithoutChatMessages() throws Exception {
+        JigsawStudioService service = new JigsawStudioService();
+        JigsawStudioProtection protection = mock(JigsawStudioProtection.class);
+        setField(service, "protection", protection);
+        PlayerInteractEvent event = probe();
+        when(protection.studioEditRefusal(event.getPlayer(), event.getClickedBlock()))
+                .thenReturn("This Jigsaw Studio variant is read-only.");
+
+        service.protectionListener.onUnauthorizedInteract(event);
+
+        assertTrue(event.isCancelled());
+        verify(protection, never()).isUnauthorizedStudioEdit(any(Player.class), any(Block.class));
+    }
+
     private static PlayerInteractEvent probe() {
         Player player = mock(Player.class);
         World world = mock(World.class);

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioResourceBundleAssemblerTest.java

@@ -80,20 +80,20 @@ public class JigsawStudioResourceBundleAssemblerTest {
                 JigsawStudioResourceBundleAssembler.assemble(
                         packRoot,
                         "fort",
-                        "fort/start",
+                        "fort/blank",
                         emptyObject(),
                         List.of(connector),
                         false);
 
-        assertEquals(17, assembly.bundle().resources().size());
+        assertEquals(51, assembly.bundle().resources().size());
-        assertEquals("fort/start", assembly.objectKey());
+        assertEquals("fort/blank", assembly.objectKey());
         assertEquals(1, assembly.piece().getConnectors().size());
         StructureWriteResult result = new StructureTransactionWriter(packRoot)
                 .write(assembly.bundle(), StructureWriteMode.OVERWRITE);
         assertTrue(result.successful());
         assertTrue(result.committed());
 
-        Path piecePath = packRoot.resolve("jigsaw-pieces/fort/start.json");
+        Path piecePath = packRoot.resolve("jigsaw-pieces/fort/blank.json");
         IrisJigsawPiece persisted = new Gson().fromJson(
                 Files.readString(piecePath, StandardCharsets.UTF_8), IrisJigsawPiece.class);
         assertEquals(1, persisted.getConnectors().size());
@@ -143,7 +143,7 @@ public class JigsawStudioResourceBundleAssemblerTest {
     @Test
     public void capturePreservesAbsentDefaultsAndUnknownPieceMetadata() throws Exception {
         Path packRoot = createProject();
-        String pieceResource = "jigsaw-pieces/fort/start.json";
+        String pieceResource = "jigsaw-pieces/fort/blank.json";
         Path piecePath = packRoot.resolve(pieceResource);
         JsonObject source = JsonParser.parseString(
                 Files.readString(piecePath, StandardCharsets.UTF_8)).getAsJsonObject();
@@ -158,7 +158,7 @@ public class JigsawStudioResourceBundleAssemblerTest {
                 JigsawStudioResourceBundleAssembler.assemble(
                         packRoot,
                         STRUCTURE_KEY,
-                        "fort/start",
+                        "fort/blank",
                         emptyObject(),
                         List.copyOf(sourcePiece.getConnectors()),
                         false);
@@ -173,7 +173,7 @@ public class JigsawStudioResourceBundleAssemblerTest {
                 JigsawStudioResourceBundleAssembler.assemble(
                         packRoot,
                         STRUCTURE_KEY,
-                        "fort/start",
+                        "fort/blank",
                         emptyObject(),
                         List.of(updated),
                         false);
@@ -202,7 +202,7 @@ public class JigsawStudioResourceBundleAssemblerTest {
                 () -> JigsawStudioResourceBundleAssembler.assemble(
                         packRoot,
                         STRUCTURE_KEY,
-                        "fort/start",
+                        "fort/blank",
                         emptyObject(),
                         List.of(connector()),
                         false));
@@ -213,7 +213,7 @@ public class JigsawStudioResourceBundleAssemblerTest {
     @Test
     public void refusesManagedDatapackOwnershipWithoutAssemblingAStudioSave() throws Exception {
         Path packRoot = createProject();
-        Path objectPath = packRoot.resolve("objects/fort/start.iob");
+        Path objectPath = packRoot.resolve("objects/fort/blank.iob");
         byte[] before = Files.readAllBytes(objectPath);
         markManagedDatapack(packRoot, STRUCTURE_KEY);
 
@@ -221,7 +221,7 @@ public class JigsawStudioResourceBundleAssemblerTest {
                 () -> JigsawStudioResourceBundleAssembler.assemble(
                         packRoot,
                         STRUCTURE_KEY,
-                        "fort/start",
+                        "fort/blank",
                         emptyObject(),
                         List.of(connector()),
                         false));
@@ -234,13 +234,13 @@ public class JigsawStudioResourceBundleAssemblerTest {
     @Test
     public void writerRejectsAResourceModifiedOutsideTheOwnershipTransaction() throws Exception {
         Path packRoot = createProject();
-        Path piecePath = packRoot.resolve("jigsaw-pieces/fort/start.json");
+        Path piecePath = packRoot.resolve("jigsaw-pieces/fort/blank.json");
         Files.writeString(piecePath, Files.readString(piecePath, StandardCharsets.UTF_8) + "\n");
         JigsawStudioResourceBundleAssembler.Assembly assembly =
                 JigsawStudioResourceBundleAssembler.assemble(
                         packRoot,
                         STRUCTURE_KEY,
-                        "fort/start",
+                        "fort/blank",
                         emptyObject(),
                         List.of(connector().setPool("fort/start")),
                         false);

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioServiceCaptureTest.java

@@ -181,11 +181,13 @@ public class JigsawStudioServiceCaptureTest {
         when(state.isCustom()).thenReturn(false);
         when(state.nativeHandle()).thenReturn(blockData);
 
-        JigsawStudioChunkWriter.restoreConnectorChunk(
+        JigsawStudioCapture.LocalPosition position = new JigsawStudioCapture.LocalPosition(1, 2, 3);
+        JigsawStudioChunkWriter.restoreChunkPositions(
                 world,
                 workcell,
-                List.of(renderedConnector),
+                Set.of(position),
-                Map.of(new JigsawStudioCapture.LocalPosition(1, 2, 3), renderedBlock),
+                Map.of(position, renderedConnector),
+                Map.of(position, renderedBlock),
                 false);
 
         verify(world).getBlockAt(11, 22, 33);
@@ -293,7 +295,9 @@ public class JigsawStudioServiceCaptureTest {
         assertFalse(JigsawStudioProtection.blocksMutatingCommand(ownerId, otherId, "/iris jigsaw status"));
         assertFalse(JigsawStudioProtection.blocksMutatingCommand(ownerId, otherId, "/msg owner hello"));
         assertTrue(JigsawStudioProtection.blocksMutatingCommand(ownerId, otherId, "/execute run say bypass"));
-        assertTrue(JigsawStudioProtection.blocksMutatingCommand(ownerId, otherId, "/unknownplugin mutate"));
+        assertTrue(JigsawStudioProtection.blocksMutatingCommand(ownerId, otherId, "/setblock 0 0 0 stone"));
+        assertFalse(JigsawStudioProtection.blocksMutatingCommand(ownerId, otherId, "/unknownplugin status"));
+        assertFalse(JigsawStudioProtection.blocksMutatingCommand(ownerId, otherId, "/spawn"));
         assertTrue(JigsawStudioProtection.blocksNonEditableWorkcellMutation(
                 true, "/fill 0 0 0 1 1 1 stone"));
         assertTrue(JigsawStudioProtection.blocksNonEditableWorkcellMutation(true, "//paste -a"));

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioToolbeltTest.java

@@ -0,0 +1,172 @@
+package art.arcane.iris.studio.jigsaw;
+
+import art.arcane.iris.generation.runtime.Engine;
+import art.arcane.iris.pack.loading.IrisData;
+import art.arcane.iris.studio.generation.JigsawStudioGenerator;
+import art.arcane.iris.world.task.J;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.junit.Test;
+import org.mockito.MockedStatic;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class JigsawStudioToolbeltTest {
+    private static final UUID REQUEST = UUID.fromString("55555555-5555-5555-5555-555555555555");
+    private static final JigsawStudioToolPayload DELETE = JigsawStudioToolPayload.variant(
+            JigsawStudioToolAction.DELETE_VARIANT, REQUEST, "workcell/end", "test/end");
+
+    @Test
+    public void heldUseRepeatsCannotConfirmADestructiveTool() {
+        JigsawStudioToolbelt.ToolConfirmation armed =
+                new JigsawStudioToolbelt.ToolConfirmation(DELETE, 1_000_000_000L, 11_000_000_000L);
+
+        assertEquals(JigsawStudioToolbelt.ToolConfirmationState.ARMED,
+                JigsawStudioToolbelt.confirmationState(null, DELETE, 1_000_000_000L));
+        assertEquals(JigsawStudioToolbelt.ToolConfirmationState.HELD,
+                JigsawStudioToolbelt.confirmationState(armed, DELETE, 1_200_000_000L));
+        assertEquals(JigsawStudioToolbelt.ToolConfirmationState.CONFIRMED,
+                JigsawStudioToolbelt.confirmationState(armed, DELETE, 1_600_000_000L));
+        assertEquals(JigsawStudioToolbelt.ToolConfirmationState.ARMED,
+                JigsawStudioToolbelt.confirmationState(armed, DELETE, 12_000_000_000L));
+        assertEquals(JigsawStudioToolbelt.ToolConfirmationState.ARMED,
+                JigsawStudioToolbelt.confirmationState(
+                        armed,
+                        JigsawStudioToolPayload.request(JigsawStudioToolAction.DELETE_PROJECT, REQUEST),
+                        1_600_000_000L));
+    }
+
+    @Test
+    public void variantBoundSticksRequireTheirBoundVariant() {
+        assertTrue(JigsawStudioToolbelt.requiresBoundVariant(JigsawStudioToolPayload.variant(
+                JigsawStudioToolAction.TOGGLE_ROTATION, REQUEST, "workcell/end", "test/end")));
+        assertTrue(JigsawStudioToolbelt.requiresBoundVariant(JigsawStudioToolPayload.variant(
+                JigsawStudioToolAction.EXPAND_TO_CELL, REQUEST, "workcell/end", "test/end")));
+        assertTrue(JigsawStudioToolbelt.requiresBoundVariant(JigsawStudioToolPayload.variant(
+                JigsawStudioToolAction.DUPLICATE_VARIANT, REQUEST, "workcell/end", "test/end")));
+        assertFalse(JigsawStudioToolbelt.requiresBoundVariant(JigsawStudioToolPayload.workcell(
+                JigsawStudioToolAction.CREATE_VARIANT, REQUEST, "workcell/end")));
+        assertFalse(JigsawStudioToolbelt.requiresBoundVariant(JigsawStudioToolPayload.request(
+                JigsawStudioToolAction.CONNECTOR_TOOL, REQUEST)));
+    }
+
+    @Test
+    public void staleRotationStickDoesNotToggleTheNewlyLoadedVariant() throws Exception {
+        JigsawStudioVariant first = variant("test/end");
+        JigsawStudioVariant second = variant("test/end-b");
+        JigsawStudioLayout layout = JigsawStudioLayout.create(
+                JigsawStudioMode.PLANAR_JIGSAW,
+                new JigsawStudioCellDimensions(16, 16, 16),
+                new JigsawStudioVariantCatalog(List.of(second, first)));
+        JigsawStudioSession session = new JigsawStudioSession(REQUEST, "overworld", "test/project", layout);
+        assertEquals("test/end-b", session.activeVariant("workcell/end").orElseThrow().pieceKey());
+        JigsawStudioService service = new JigsawStudioService();
+        JigsawStudioVariantProperties properties = mock(JigsawStudioVariantProperties.class);
+        setField(service, "variantProperties", properties);
+        Player player = player(service, session);
+
+        try (MockedStatic<J> scheduling = mockStatic(J.class)) {
+            scheduling.when(() -> J.isOwnedByCurrentRegion(any(Player.class))).thenReturn(true);
+
+            boolean used = service.toolbelt.useTool(
+                    player,
+                    JigsawStudioToolPayload.variant(
+                            JigsawStudioToolAction.TOGGLE_ROTATION, REQUEST, "workcell/end", "test/end"),
+                    null,
+                    false);
+
+            assertFalse(used);
+            verify(properties, never()).toggleVariantRotatable(any(Player.class), anyString());
+        }
+    }
+
+    private static Player player(JigsawStudioService service, JigsawStudioSession session) throws Exception {
+        UUID worldId = UUID.randomUUID();
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(worldId);
+        Player player = mock(Player.class);
+        when(player.getWorld()).thenReturn(world);
+        when(player.getUniqueId()).thenReturn(UUID.randomUUID());
+        JigsawStudioActivation.Request request = new JigsawStudioActivation.Request(
+                REQUEST,
+                "overworld",
+                "test/project",
+                JigsawStudioMode.PLANAR_JIGSAW,
+                JigsawStudioCompatibilityTarget.IRIS_EXTENDED,
+                new JigsawStudioCellDimensions(16, 16, 16),
+                mock(IrisData.class),
+                null);
+        JigsawStudioGenerator generator = mock(JigsawStudioGenerator.class);
+        when(generator.getRequest()).thenReturn(request);
+        when(generator.getSession()).thenReturn(session);
+        when(generator.getLayout()).thenAnswer(invocation -> session.layout());
+        Class<?> studioType = Class.forName(JigsawStudioService.class.getName() + "$ActiveStudio");
+        Constructor<?> constructor = studioType.getDeclaredConstructor(
+                UUID.class,
+                World.class,
+                Engine.class,
+                JigsawStudioGenerator.class,
+                ConcurrentHashMap.class,
+                Set.class,
+                AtomicLong.class);
+        constructor.setAccessible(true);
+        Object studio = constructor.newInstance(
+                worldId,
+                world,
+                mock(Engine.class),
+                generator,
+                new ConcurrentHashMap<>(),
+                ConcurrentHashMap.newKeySet(),
+                new AtomicLong());
+        @SuppressWarnings("unchecked")
+        Map<UUID, Object> studios = (Map<UUID, Object>) getField(service, "studios");
+        studios.put(worldId, studio);
+        return player;
+    }
+
+    private static JigsawStudioVariant variant(String pieceKey) {
+        return new JigsawStudioVariant(
+                pieceKey,
+                pieceKey,
+                "",
+                Optional.of(new JigsawStudioCellDimensions(16, 16, 16)),
+                JigsawStudioMode.PLANAR_JIGSAW,
+                Optional.of(JigsawPlanarTopology.NORTH_END),
+                true,
+                true,
+                List.of(),
+                new JigsawStudioPieceRules(0, 30, 0, 0, false),
+                List.of());
+    }
+
+    private static void setField(Object target, String name, Object value) throws Exception {
+        Field field = target.getClass().getDeclaredField(name);
+        field.setAccessible(true);
+        field.set(target, value);
+    }
+
+    private static Object getField(Object target, String name) throws Exception {
+        Field field = target.getClass().getDeclaredField(name);
+        field.setAccessible(true);
+        return field.get(target);
+    }
+}

core/src/test/java/art/arcane/iris/studio/jigsaw/JigsawStudioVariantDeletionRuleTest.java

@@ -0,0 +1,99 @@
+package art.arcane.iris.studio.jigsaw;
+
+import org.junit.Test;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class JigsawStudioVariantDeletionRuleTest {
+    private static final UUID WORLD = UUID.randomUUID();
+    private static final UUID REQUEST = UUID.randomUUID();
+
+    @Test
+    public void spatialVariantsCanBeDeletedWhileLoadedUnlessTheyAreTheLastOne() {
+        JigsawStudioMenuState.Variant first = variant("demo/end", true, true);
+        JigsawStudioMenuState.Variant second = variant("demo/cross", true, true);
+        JigsawStudioMenuState.Workcell firstCell = workcell("workcell/spatial", first);
+        JigsawStudioMenuState.Workcell secondCell = workcell("workcell/spatial/demo/cross", second);
+        JigsawStudioMenuState twoCells = state(JigsawStudioMode.SPATIAL_JIGSAW, List.of(firstCell, secondCell));
+        JigsawStudioMenuState oneCell = state(JigsawStudioMode.SPATIAL_JIGSAW, List.of(firstCell));
+
+        assertTrue(twoCells.canDeleteVariant(firstCell, first));
+        assertFalse(oneCell.canDeleteVariant(firstCell, first));
+        List<JigsawStudioToolboxMenu.ToolboxTool> tools = JigsawStudioToolboxMenu.toolboxTools(twoCells, firstCell);
+        assertTrue(tools.stream().anyMatch(tool -> tool.payload().action() == JigsawStudioToolAction.DELETE_VARIANT
+                && tool.payload().pieceKey().equals("demo/end")));
+    }
+
+    @Test
+    public void planarVariantsStillRequireAnotherLoadedVariantFirst() {
+        JigsawStudioMenuState.Variant loaded = variant("demo/end", true, true);
+        JigsawStudioMenuState.Variant spare = variant("demo/end-b", false, true);
+        JigsawStudioMenuState.Variant readOnly = variant("demo/end-c", false, false);
+        JigsawStudioMenuState.Workcell cell = new JigsawStudioMenuState.Workcell(
+                "workcell/end",
+                "End Cap",
+                "End Cap",
+                new JigsawStudioCellDimensions(16, 16, 16),
+                true,
+                loaded.pieceKey(),
+                false,
+                false,
+                false,
+                false,
+                List.of(loaded, spare, readOnly));
+        JigsawStudioMenuState state = state(JigsawStudioMode.PLANAR_JIGSAW, List.of(cell));
+
+        assertFalse(state.canDeleteVariant(cell, loaded));
+        assertTrue(state.canDeleteVariant(cell, spare));
+        assertFalse(state.canDeleteVariant(cell, readOnly));
+    }
+
+    private static JigsawStudioMenuState state(JigsawStudioMode mode, List<JigsawStudioMenuState.Workcell> workcells) {
+        return new JigsawStudioMenuState(
+                WORLD,
+                REQUEST,
+                "demo",
+                mode,
+                JigsawStudioCompatibilityTarget.IRIS_EXTENDED,
+                false,
+                List.of(new JigsawStudioMenuState.ThemeSet("variant-1", 1)),
+                workcells.getFirst().stableId(),
+                JigsawStudioMenuState.Evaluation.pending(),
+                workcells);
+    }
+
+    private static JigsawStudioMenuState.Workcell workcell(String stableId, JigsawStudioMenuState.Variant active) {
+        return new JigsawStudioMenuState.Workcell(
+                stableId,
+                "Spatial",
+                active.displayName(),
+                new JigsawStudioCellDimensions(15, 15, 15),
+                true,
+                active.pieceKey(),
+                false,
+                false,
+                false,
+                false,
+                List.of(active));
+    }
+
+    private static JigsawStudioMenuState.Variant variant(String pieceKey, boolean active, boolean owned) {
+        return new JigsawStudioMenuState.Variant(
+                pieceKey,
+                pieceKey.substring(pieceKey.lastIndexOf('/') + 1),
+                Optional.of(new JigsawStudioCellDimensions(15, 15, 15)),
+                active,
+                owned,
+                true,
+                owned,
+                active,
+                List.of(),
+                new JigsawStudioPieceRules(0, 30, 0, 0, false),
+                List.of());
+    }
+}