feat: customizable connection points per side (issue #243)

Generalize the bottom-only handle machinery to all four sides. Top/Bottom
keep their single-handle default; Left/Right are opt-in (default 0) so
existing diagrams render unchanged. Handle IDs stay keyed off the bare side
name at slot 0, keeping saved edges valid.

- handleUtils: side-generic API (handleId, handlePositions, clampHandles,
  sideDefault, removedHandleIds, sideHandleCount); legacy bottom fns kept as
  delegating aliases
- BaseNode + ProxmoxGroupNode render all sides via new shared SideHandles
- updateNode remaps edges on any side's shrink (fallback to slot-0 / bottom)
- serializer round-trips top/left/right_handles
- NodeModal: spatial cross of -/N/+ steppers around a node preview, replacing
  the four stacked sliders; seeds per-type defaults
- CustomStyleModal: per-type default connection points per side

ha-relevant: yes

frontend/src/components/canvas/__tests__/BaseNode.test.tsx

@@ -9,7 +9,7 @@ let mockZoom = 1
 
 vi.mock('@xyflow/react', () => ({
   Handle: () => null,
-  Position: { Top: 'top', Bottom: 'bottom' },
+  Position: { Top: 'top', Bottom: 'bottom', Left: 'left', Right: 'right' },
   NodeResizer: () => null,
   useUpdateNodeInternals: () => vi.fn(),
   useViewport: () => ({ zoom: mockZoom }),
@@ -59,14 +59,9 @@ vi.mock('@/utils/propertyIcons', () => ({
   resolvePropertyIcon: (icon: string | null) => icon ? Server : null,
 }))
 
-vi.mock('@/utils/handleUtils', () => ({
-  bottomHandleId: (idx: number) => idx === 0 ? 'bottom' : `bottom-${idx + 1}`,
-  bottomHandlePositions: (count: number) => {
-    const c = typeof count === 'number' && count > 0 ? Math.floor(count) : 1
-    return Array.from({ length: c }, (_, i) => ((i + 1) * 100) / (c + 1))
-  },
-  clampBottomHandles: (n: unknown) => typeof n === 'number' ? n : 1,
-}))
+// handleUtils is pure — use the real implementation so the side-generic API
+// (SIDES, handleId, handlePositions, sideHandleCount, …) stays in sync.
+vi.mock('@/utils/handleUtils', async (importOriginal) => await importOriginal())
 
 beforeEach(() => { mockZoom = 1 })
 
@@ -176,15 +171,23 @@ describe('BaseNode — properties rendering', () => {
   })
 })
 
-describe('BaseNode — port numbers (issue #20)', () => {
-  it('renders a number above each bottom handle when show_port_numbers is on', () => {
+describe('BaseNode — port numbers (issue #20 / #243)', () => {
+  it('renders a number on each connection point when show_port_numbers is on', () => {
+    // bottom=4 → labels 1..4; top defaults to 1 → an extra "1" on top.
     renderBaseNode({ bottom_handles: 4, show_port_numbers: true })
-    expect(screen.getByText('1')).toBeDefined()
+    expect(screen.getAllByText('1')).toHaveLength(2) // top slot 0 + bottom slot 0
     expect(screen.getByText('2')).toBeDefined()
     expect(screen.getByText('3')).toBeDefined()
     expect(screen.getByText('4')).toBeDefined()
   })
 
+  it('labels left/right connection points too when enabled', () => {
+    // top=1, bottom=1, left=2, right=0 → labels: two "1" (top+bottom) + "2" (left).
+    renderBaseNode({ bottom_handles: 1, left_handles: 2, show_port_numbers: true })
+    expect(screen.getByText('2')).toBeDefined()
+    expect(screen.getAllByText('1')).toHaveLength(3) // top + bottom + left slot 0
+  })
+
   it('does not render port numbers when show_port_numbers is off', () => {
     renderBaseNode({ bottom_handles: 4 })
     expect(screen.queryByText('1')).toBeNull()
@@ -192,8 +195,9 @@ describe('BaseNode — port numbers (issue #20)', () => {
   })
 
   it('numbers match the handle count', () => {
+    // bottom=2 → 1,2; top default 1 adds one more "1"; no "3".
     renderBaseNode({ bottom_handles: 2, show_port_numbers: true })
-    expect(screen.getByText('1')).toBeDefined()
+    expect(screen.getAllByText('1')).toHaveLength(2)
     expect(screen.getByText('2')).toBeDefined()
     expect(screen.queryByText('3')).toBeNull()
   })

frontend/src/components/canvas/nodes/BaseNode.tsx

@@ -1,5 +1,5 @@
 import { createElement, useEffect, useMemo } from 'react'
-import { Handle, Position, NodeResizer, useUpdateNodeInternals, useViewport, type NodeProps, type Node } from '@xyflow/react'
+import { NodeResizer, useUpdateNodeInternals, useViewport, type NodeProps, type Node } from '@xyflow/react'
 import { Cpu, MemoryStick, HardDrive, ExternalLink, type LucideIcon } from 'lucide-react'
 import type { NodeData } from '@/types'
 import { resolveNodeColors } from '@/utils/nodeColors'
@@ -10,7 +10,8 @@ import { useThemeStore } from '@/stores/themeStore'
 import { THEMES } from '@/utils/themes'
 import { useCanvasStore, serviceStatusKey } from '@/stores/canvasStore'
 import { maskIp, primaryIp, splitIps } from '@/utils/maskIp'
-import { bottomHandleId, bottomHandlePositions, clampBottomHandles } from '@/utils/handleUtils'
+import { sideHandleCount } from '@/utils/handleUtils'
+import { SideHandles } from './SideHandles'
 import { getServiceUrl } from '@/utils/serviceUrl'
 
 interface BaseNodeProps extends NodeProps<Node<NodeData>> {
@@ -24,7 +25,7 @@ function formatStorage(gb: number): string {
 
 export function BaseNode({ id, data, selected, icon: typeIcon, width, height }: BaseNodeProps) {
   const updateNodeInternals = useUpdateNodeInternals()
-  useEffect(() => { updateNodeInternals(id) }, [data.bottom_handles, id, updateNodeInternals])
+  useEffect(() => { updateNodeInternals(id) }, [data.top_handles, data.bottom_handles, data.left_handles, data.right_handles, id, updateNodeInternals])
 
   const { zoom } = useViewport()
   const borderWidth = useMemo(() => Math.max(1, 1 / zoom), [zoom])
@@ -47,6 +48,12 @@ export function BaseNode({ id, data, selected, icon: typeIcon, width, height }:
   const showLegacyHardware = !data.properties && data.show_hardware &&
     (data.cpu_count != null || data.cpu_model || data.ram_gb != null || data.disk_gb != null)
 
+  // Resolved per-side connection-point counts (missing field → side default).
+  const topCount = sideHandleCount(data, 'top')
+  const bottomCount = sideHandleCount(data, 'bottom')
+  const leftCount = sideHandleCount(data, 'left')
+  const rightCount = sideHandleCount(data, 'right')
+
   return (
     <div
       className="relative flex flex-col rounded-lg border transition-all duration-200 overflow-hidden"
@@ -62,8 +69,9 @@ export function BaseNode({ id, data, selected, icon: typeIcon, width, height }:
           ? `0 0 0 ${borderWidth}px ${colors.border}, 0 0 8px ${colors.border}44`
           : 'none',
         opacity: data.status === 'offline' ? 0.55 : 1,
-        // Grow node width when many bottom handles so each stays clickable (~14px slot).
-        minWidth: Math.max(140, clampBottomHandles(data.bottom_handles ?? 1) * 14),
+        // Grow node so each handle stays clickable (~14px slot on each axis).
+        minWidth: Math.max(140, Math.max(topCount, bottomCount) * 14),
+        minHeight: Math.max(50, Math.max(leftCount, rightCount) * 14),
         width: width ? '100%' : undefined,
         height: height ? '100%' : undefined,
       }}
@@ -75,13 +83,14 @@ export function BaseNode({ id, data, selected, icon: typeIcon, width, height }:
         lineStyle={{ borderColor: 'transparent' }}
         handleStyle={{ borderColor: colors.border, background: colors.border, width: 16, height: 16 }}
       />
-      <Handle
-        type="source"
-        position={Position.Top}
-        id="top"
-        style={{ background: theme.colors.handleBackground, borderColor: theme.colors.handleBorder }}
+      <SideHandles
+        data={data}
+        sides={['top', 'left', 'right']}
+        handleBackground={theme.colors.handleBackground}
+        handleBorder={theme.colors.handleBorder}
+        labelColor={theme.colors.nodeSubtextColor}
+        showLabels
       />
-      <Handle type="target" position={Position.Top} id="top-t" style={{ opacity: 0, width: 12, height: 12 }} />
 
       {/* Status dot — absolute to avoid affecting node auto-width */}
       <div
@@ -251,40 +260,14 @@ export function BaseNode({ id, data, selected, icon: typeIcon, width, height }:
         </>
       )}
 
-      {bottomHandlePositions(data.bottom_handles ?? 1).map((leftPct, idx) => {
-        const sourceId = bottomHandleId(idx)
-        const targetId = `${sourceId}-t`
-        return (
-          <span key={sourceId}>
-            {data.show_port_numbers && (
-              <span
-                className="absolute font-mono leading-none pointer-events-none select-none"
-                style={{
-                  left: `${leftPct}%`,
-                  bottom: 3,
-                  transform: 'translateX(-50%)',
-                  fontSize: 7,
-                  color: theme.colors.nodeSubtextColor,
-                }}
-              >
-                {idx + 1}
-              </span>
-            )}
-            <Handle
-              type="source"
-              position={Position.Bottom}
-              id={sourceId}
-              style={{ left: `${leftPct}%`, background: theme.colors.handleBackground, borderColor: theme.colors.handleBorder }}
-            />
-            <Handle
-              type="target"
-              position={Position.Bottom}
-              id={targetId}
-              style={{ left: `${leftPct}%`, opacity: 0, width: 12, height: 12 }}
-            />
-          </span>
-        )
-      })}
+      <SideHandles
+        data={data}
+        sides={['bottom']}
+        handleBackground={theme.colors.handleBackground}
+        handleBorder={theme.colors.handleBorder}
+        labelColor={theme.colors.nodeSubtextColor}
+        showLabels
+      />
     </div>
   )
 }

frontend/src/components/canvas/nodes/ProxmoxGroupNode.tsx

@@ -10,13 +10,13 @@ import { useCanvasStore } from '@/stores/canvasStore'
 import { maskIp, splitIps } from '@/utils/maskIp'
 import { useThemeStore } from '@/stores/themeStore'
 import { THEMES } from '@/utils/themes'
-import { bottomHandleId, bottomHandlePositions } from '@/utils/handleUtils'
 import { BaseNode } from './BaseNode'
+import { SideHandles } from './SideHandles'
 
 export function ProxmoxGroupNode(props: NodeProps<Node<NodeData>>) {
   const { id, data, selected } = props
   const updateNodeInternals = useUpdateNodeInternals()
-  useEffect(() => { updateNodeInternals(id) }, [data.bottom_handles, id, updateNodeInternals])
+  useEffect(() => { updateNodeInternals(id) }, [data.top_handles, data.bottom_handles, data.left_handles, data.right_handles, id, updateNodeInternals])
 
   const activeTheme = useThemeStore((s) => s.activeTheme)
   const hideIp = useCanvasStore((s) => s.hideIp)
@@ -145,33 +145,12 @@ export function ProxmoxGroupNode(props: NodeProps<Node<NodeData>>) {
         <div className="flex-1 relative" />
       </div>
 
-      <Handle
-        type="source"
-        position={Position.Top}
-        id="top"
-        style={{ background: theme.colors.handleBackground, borderColor: theme.colors.handleBorder }}
+      <SideHandles
+        data={data}
+        handleBackground={theme.colors.handleBackground}
+        handleBorder={theme.colors.handleBorder}
+        labelColor={theme.colors.nodeSubtextColor}
       />
-      <Handle type="target" position={Position.Top} id="top-t" style={{ opacity: 0, width: 12, height: 12 }} />
-      {bottomHandlePositions(data.bottom_handles ?? 1).map((leftPct, idx) => {
-        const sourceId = bottomHandleId(idx)
-        const targetId = `${sourceId}-t`
-        return (
-          <span key={sourceId}>
-            <Handle
-              type="source"
-              position={Position.Bottom}
-              id={sourceId}
-              style={{ left: `${leftPct}%`, background: theme.colors.handleBackground, borderColor: theme.colors.handleBorder }}
-            />
-            <Handle
-              type="target"
-              position={Position.Bottom}
-              id={targetId}
-              style={{ left: `${leftPct}%`, opacity: 0, width: 12, height: 12 }}
-            />
-          </span>
-        )
-      })}
 
       {/* Cluster handles */}
       <Handle

frontend/src/components/canvas/nodes/SideHandles.tsx

@@ -0,0 +1,84 @@
+import type { CSSProperties } from 'react'
+import { Handle, Position } from '@xyflow/react'
+import type { NodeData } from '@/types'
+import {
+  SIDES,
+  handleId,
+  handlePositions,
+  isVerticalSide,
+  sideHandleCount,
+  type Side,
+} from '@/utils/handleUtils'
+
+const POSITION: Record<Side, Position> = {
+  top: Position.Top,
+  bottom: Position.Bottom,
+  left: Position.Left,
+  right: Position.Right,
+}
+
+interface SideHandlesProps {
+  data: NodeData
+  handleBackground: string
+  handleBorder: string
+  /** Colour for the optional port-number labels. */
+  labelColor: string
+  /** Which sides to render. Defaults to all four. */
+  sides?: readonly Side[]
+  /** When true, render port-number labels if data.show_port_numbers is set. */
+  showLabels?: boolean
+}
+
+/**
+ * Renders the per-side React Flow handles (visible source + invisible target)
+ * for a node, spaced along each side's axis. Shared by BaseNode and the
+ * container-mode ProxmoxGroupNode so handle IDs stay identical across both.
+ */
+export function SideHandles({
+  data,
+  handleBackground,
+  handleBorder,
+  labelColor,
+  sides = SIDES,
+  showLabels = false,
+}: SideHandlesProps) {
+  return (
+    <>
+      {sides.map((side) => {
+        const vertical = isVerticalSide(side)
+        return handlePositions(side, sideHandleCount(data, side)).map((pct, idx) => {
+          const sourceId = handleId(side, idx)
+          const targetId = `${sourceId}-t`
+          const offset: CSSProperties = vertical ? { top: `${pct}%` } : { left: `${pct}%` }
+          const labelStyle: CSSProperties = vertical
+            ? { top: `${pct}%`, [side]: 3, transform: 'translateY(-50%)' }
+            : { left: `${pct}%`, [side]: 3, transform: 'translateX(-50%)' }
+          return (
+            <span key={sourceId}>
+              {showLabels && data.show_port_numbers && (
+                <span
+                  className="absolute font-mono leading-none pointer-events-none select-none"
+                  style={{ ...labelStyle, fontSize: 7, color: labelColor }}
+                >
+                  {idx + 1}
+                </span>
+              )}
+              <Handle
+                type="source"
+                position={POSITION[side]}
+                id={sourceId}
+                style={{ ...offset, background: handleBackground, borderColor: handleBorder }}
+              />
+              <Handle
+                type="target"
+                position={POSITION[side]}
+                id={targetId}
+                style={{ ...offset, opacity: 0, width: 12, height: 12 }}
+              />
+            </span>
+          )
+        })
+      })}
+    </>
+  )
+}

frontend/src/components/modals/CustomStyleModal.tsx

@@ -10,6 +10,7 @@ import { Dialog, DialogContent, DialogHeader, DialogTitle } from '@/components/u
 import { Button } from '@/components/ui/button'
 import { useThemeStore } from '@/stores/themeStore'
 import { useCanvasStore } from '@/stores/canvasStore'
+import { clampHandles, sideDefault } from '@/utils/handleUtils'
 import { THEMES } from '@/utils/themes'
 import { applyOpacity } from '@/utils/colorUtils'
 import type {
@@ -178,6 +179,33 @@ function NodeEditor({ nodeType, style, onChange, onApplyToExisting }: NodeEditor
         </div>
       </div>
 
+      <div className="border-t border-[#30363d] pt-3">
+        <div className="text-xs text-[#8b949e] mb-1">Default connection points</div>
+        <div className="text-xs text-[#8b949e]/60 mb-2">New {NODE_TYPE_LABELS[nodeType]} nodes start with these (0–64 per side)</div>
+        <div className="grid grid-cols-2 gap-2">
+          {([
+            ['Top', 'top', 'topHandles'],
+            ['Right', 'right', 'rightHandles'],
+            ['Bottom', 'bottom', 'bottomHandles'],
+            ['Left', 'left', 'leftHandles'],
+          ] as const).map(([label, side, key]) => (
+            <div key={side} className="flex items-center gap-2">
+              <span className="text-xs text-[#8b949e] w-12">{label}</span>
+              <input
+                type="number"
+                min={sideDefault(side)}
+                max={64}
+                step={1}
+                value={style[key] ?? sideDefault(side)}
+                onChange={(e) => set(key, clampHandles(side, parseInt(e.target.value, 10)))}
+                aria-label={`${label} default connection points`}
+                className="w-16 h-7 text-xs bg-[#0d1117] border border-[#30363d] rounded px-2 text-[#e6edf3]"
+              />
+            </div>
+          ))}
+        </div>
+      </div>
+
       <Button
         size="sm"
         className="self-start bg-[#00d4ff] text-[#0d1117] hover:bg-[#00d4ff]/90"

frontend/src/components/modals/NodeModal.tsx

@@ -6,11 +6,12 @@ import { Button } from '@/components/ui/button'
 import { Input } from '@/components/ui/input'
 import { Label } from '@/components/ui/label'
 import { Select, SelectContent, SelectGroup, SelectItem, SelectLabel, SelectSeparator, SelectTrigger, SelectValue } from '@/components/ui/select'
-import { NODE_TYPE_LABELS, type NodeData, type NodeType, type CheckMethod } from '@/types'
+import { NODE_TYPE_LABELS, type NodeData, type NodeType, type CheckMethod, type NodeTypeStyle } from '@/types'
+import { useThemeStore } from '@/stores/themeStore'
 import { resolveNodeColors } from '@/utils/nodeColors'
 import { ICON_REGISTRY, ICON_CATEGORIES, NODE_TYPE_DEFAULT_ICONS, isBrandIconKey, brandIconSlug, brandIconUrl } from '@/utils/nodeIcons'
 import { BrandIconPicker } from './BrandIconPicker'
-import { MIN_BOTTOM_HANDLES, MAX_BOTTOM_HANDLES, clampBottomHandles } from '@/utils/handleUtils'
+import { MAX_HANDLES, clampHandles, sideDefault, handleCountField, type Side } from '@/utils/handleUtils'
 import { getValidParentTypes } from '@/utils/virtualEdgeParent'
 
 const NODE_TYPE_GROUPS: { label: string; types: NodeType[] }[] = [
@@ -24,6 +25,65 @@ const NODE_TYPE_GROUPS: { label: string; types: NodeType[] }[] = [
   { label: 'Generic',        types: ['generic', 'groupRect'] },
 ]
 
+// Maps a side to its per-type default field on NodeTypeStyle.
+const SIDE_STYLE_KEY: Record<Side, keyof NodeTypeStyle> = {
+  top: 'topHandles',
+  bottom: 'bottomHandles',
+  left: 'leftHandles',
+  right: 'rightHandles',
+}
+
+/**
+ * Compact per-side connection-point control: [− N +] with a typable value.
+ * Placed spatially around a node preview (see the Connection Points section).
+ */
+function CPStepper({ label, side, value, onChange }: {
+  label: string
+  side: Side
+  value: number
+  onChange: (v: number) => void
+}) {
+  const min = sideDefault(side)
+  const labelEl = <span className="text-[10px] text-muted-foreground/80 leading-none">{label}</span>
+  const belowLabel = side === 'bottom'
+  const btn = 'w-6 h-full flex items-center justify-center text-sm text-muted-foreground hover:text-foreground hover:bg-[#21262d] disabled:opacity-30 disabled:hover:bg-transparent disabled:cursor-default'
+  return (
+    <div className="flex flex-col items-center gap-1">
+      {!belowLabel && labelEl}
+      <div className="flex items-center h-7 rounded-md border border-[#30363d] bg-[#0d1117] overflow-hidden">
+        <button
+          type="button"
+          aria-label={`Decrease ${label} connection points`}
+          onClick={() => onChange(clampHandles(side, value - 1))}
+          disabled={value <= min}
+          className={btn}
+        >
+          −
+        </button>
+        <input
+          type="number"
+          min={min}
+          max={MAX_HANDLES}
+          value={value}
+          aria-label={`${label} connection points`}
+          onChange={(e) => onChange(clampHandles(side, Number(e.target.value)))}
+          className="w-9 h-full bg-transparent text-center text-xs font-mono text-foreground outline-none [appearance:textfield] [&::-webkit-inner-spin-button]:appearance-none [&::-webkit-outer-spin-button]:appearance-none"
+        />
+        <button
+          type="button"
+          aria-label={`Increase ${label} connection points`}
+          onClick={() => onChange(clampHandles(side, value + 1))}
+          disabled={value >= MAX_HANDLES}
+          className={btn}
+        >
+          +
+        </button>
+      </div>
+      {belowLabel && labelEl}
+    </div>
+  )
+}
+
 const CHECK_METHODS: CheckMethod[] = ['none', 'ping', 'http', 'https', 'tcp', 'ssh', 'prometheus', 'health']
 const CONTAINER_MODE_TYPES: NodeType[] = ['proxmox', 'vm', 'lxc', 'docker_host']
 const ZIGBEE_TYPES: NodeType[] = ['zigbee_coordinator', 'zigbee_router', 'zigbee_enddevice']
@@ -94,6 +154,16 @@ export function NodeModal({ open, onClose, onSubmit, initial, title = 'Add Node'
   const set = (key: keyof NodeData, value: unknown) =>
     setForm((f) => ({ ...f, [key]: value }))
 
+  const customStyle = useThemeStore((s) => s.customStyle)
+  // Effective default count for a side: the per-type style default if set,
+  // otherwise the intrinsic side default (top/bottom → 1, left/right → 0).
+  const effectiveSideDefault = (side: Side): number => {
+    const styleVal = customStyle.nodes[(form.type ?? 'generic') as NodeType]?.[SIDE_STYLE_KEY[side]]
+    return clampHandles(side, typeof styleVal === 'number' ? styleVal : sideDefault(side))
+  }
+  const sideValue = (side: Side): number =>
+    clampHandles(side, form[handleCountField(side)] ?? effectiveSideDefault(side))
+
   const handleSubmit = (e: React.FormEvent) => {
     e.preventDefault()
     if (!form.label?.trim()) {
@@ -113,8 +183,17 @@ export function NodeModal({ open, onClose, onSubmit, initial, title = 'Add Node'
       const parent = parentCandidates.find((n) => n.id === safeParentId)
       if (!parent || !isValidParent(parent)) safeParentId = undefined
     }
+    const isGroupType = selectedType === 'groupRect' || selectedType === 'group'
     onSubmit({
       ...form,
+      // Persist the resolved per-side counts so type-style defaults (and
+      // untouched sliders) are baked into the node. Skipped for group types.
+      ...(isGroupType ? {} : {
+        top_handles: sideValue('top'),
+        bottom_handles: sideValue('bottom'),
+        left_handles: sideValue('left'),
+        right_handles: sideValue('right'),
+      }),
       parent_id: safeParentId,
       container_mode: canUseContainerMode ? !!form.container_mode : false,
     })
@@ -509,31 +588,42 @@ export function NodeModal({ open, onClose, onSubmit, initial, title = 'Add Node'
               </div>
             </div>
 
-            {/* Bottom connection points (not for group containers) */}
+            {/* Connection points per side (not for group containers) */}
             {form.type !== 'groupRect' && form.type !== 'group' && (
-              <div className="flex flex-col gap-1.5 col-span-2">
-                <div className="flex items-center justify-between">
-                  <Label className="text-xs text-muted-foreground">Bottom Connection Points</Label>
-                  <span className="text-xs font-mono text-foreground">{clampBottomHandles(form.bottom_handles ?? 1)}</span>
-                </div>
-                <input
-                  type="range"
-                  min={MIN_BOTTOM_HANDLES}
-                  max={MAX_BOTTOM_HANDLES}
-                  step={1}
-                  value={clampBottomHandles(form.bottom_handles ?? 1)}
-                  onChange={(e) => set('bottom_handles', clampBottomHandles(Number(e.target.value)))}
-                  aria-label="Bottom connection points slider"
-                  className="w-full accent-[#00d4ff] cursor-pointer"
-                />
-                <div className="flex justify-between text-[10px] text-muted-foreground/60 font-mono">
-                  <span>{MIN_BOTTOM_HANDLES}</span>
-                  <span>{MAX_BOTTOM_HANDLES}</span>
+              <div className="flex flex-col gap-2.5 col-span-2">
+                <Label className="text-xs text-muted-foreground">Connection Points</Label>
+                {/* Spatial cross: each side's stepper sits where that side is. */}
+                <div className="grid grid-cols-[1fr_auto_1fr] items-center justify-items-center gap-x-2 gap-y-2 py-1">
+                  <div />
+                  <CPStepper label="Top" side="top" value={sideValue('top')}
+                    onChange={(v) => set('top_handles', v)} />
+                  <div />
+
+                  <CPStepper label="Left" side="left" value={sideValue('left')}
+                    onChange={(v) => set('left_handles', v)} />
+                  <div
+                    className="flex items-center justify-center rounded-md border text-[9px] uppercase tracking-wide font-medium select-none"
+                    style={{
+                      width: 64, height: 40,
+                      borderColor: resolvedNodeColors.border,
+                      background: `${resolvedNodeColors.background}`,
+                      color: resolvedNodeColors.icon,
+                    }}
+                  >
+                    node
+                  </div>
+                  <CPStepper label="Right" side="right" value={sideValue('right')}
+                    onChange={(v) => set('right_handles', v)} />
+
+                  <div />
+                  <CPStepper label="Bottom" side="bottom" value={sideValue('bottom')}
+                    onChange={(v) => set('bottom_handles', v)} />
+                  <div />
                 </div>
                 <div className="flex items-center justify-between pt-1">
                   <div className="flex flex-col gap-0.5">
                     <Label className="text-xs text-muted-foreground">Show Port Numbers</Label>
-                    <span className="text-[10px] text-muted-foreground/60">Label each bottom connection point</span>
+                    <span className="text-[10px] text-muted-foreground/60">Label each connection point</span>
                   </div>
                   <button
                     type="button"

frontend/src/components/modals/__tests__/CustomStyleModal.test.tsx

@@ -135,6 +135,34 @@ describe('CustomStyleModal', () => {
     expect((widthInputs[0] as HTMLInputElement).value).toBe('250')
   })
 
+  it('shows per-side default connection-point inputs in the node editor', () => {
+    render(<CustomStyleModal open onClose={vi.fn()} />)
+    fireEvent.click(screen.getByRole('button', { name: 'Router' }))
+    expect(screen.getByText('Default connection points')).toBeDefined()
+    expect(screen.getByLabelText('Top default connection points')).toBeDefined()
+    expect(screen.getByLabelText('Left default connection points')).toBeDefined()
+  })
+
+  it('defaults per-side inputs to 1 (top/bottom) and 0 (left/right)', () => {
+    render(<CustomStyleModal open onClose={vi.fn()} />)
+    fireEvent.click(screen.getByRole('button', { name: 'Router' }))
+    expect((screen.getByLabelText('Top default connection points') as HTMLInputElement).value).toBe('1')
+    expect((screen.getByLabelText('Left default connection points') as HTMLInputElement).value).toBe('0')
+  })
+
+  it('editing a per-side default persists via setCustomStyle on Save', () => {
+    const onClose = vi.fn()
+    useCanvasStore.setState({ markUnsaved: vi.fn() })
+    const setCustomStyle = vi.spyOn(useThemeStore.getState(), 'setCustomStyle')
+    render(<CustomStyleModal open onClose={onClose} />)
+    fireEvent.click(screen.getByRole('button', { name: 'Router' }))
+    fireEvent.change(screen.getByLabelText('Left default connection points'), { target: { value: '3' } })
+    fireEvent.click(screen.getByRole('button', { name: 'Save Custom Style' }))
+    expect(setCustomStyle).toHaveBeenCalled()
+    const saved = setCustomStyle.mock.calls.at(-1)?.[0]
+    expect(saved?.nodes.router?.leftHandles).toBe(3)
+  })
+
   it('resets abandoned edits when reopened after cancel (mounted parent)', () => {
     // Parent keeps the modal mounted and only toggles `open`, so the reset must
     // happen on the open-prop edge, not via Radix onOpenChange.

frontend/src/components/modals/__tests__/NodeModal.test.tsx

@@ -435,57 +435,88 @@ describe('NodeModal', () => {
     expect(screen.getByText(/Using default colors for/)).toBeDefined()
   })
 
-  // ── Bottom connection points ───────────────────────────────────────────
+  // ── Connection points per side (issue #243) ────────────────────────────
 
-  it('shows Bottom Connection Points for server type', () => {
+  it('shows the Connection Points section for server type', () => {
     renderModal({ initial: BASE })
-    expect(screen.getByText('Bottom Connection Points')).toBeDefined()
+    expect(screen.getByText('Connection Points')).toBeDefined()
+    expect(screen.getByLabelText('Top connection points')).toBeDefined()
+    expect(screen.getByLabelText('Right connection points')).toBeDefined()
+    expect(screen.getByLabelText('Bottom connection points')).toBeDefined()
+    expect(screen.getByLabelText('Left connection points')).toBeDefined()
   })
 
-  it('hides Bottom Connection Points for groupRect', () => {
+  it('hides Connection Points for groupRect', () => {
     renderModal({ initial: { ...BASE, type: 'groupRect' } })
-    expect(screen.queryByText('Bottom Connection Points')).toBeNull()
+    expect(screen.queryByText('Connection Points')).toBeNull()
   })
 
-  it('hides Bottom Connection Points for group', () => {
+  it('hides Connection Points for group', () => {
     renderModal({ initial: { ...BASE, type: 'group' } })
-    expect(screen.queryByText('Bottom Connection Points')).toBeNull()
+    expect(screen.queryByText('Connection Points')).toBeNull()
   })
 
-  it('defaults bottom_handles to 1', () => {
+  it('defaults top/bottom to 1 and left/right to 0', () => {
     renderModal({ initial: BASE })
-    const slider = screen.getByLabelText('Bottom connection points slider') as HTMLInputElement
-    expect(slider.value).toBe('1')
+    expect((screen.getByLabelText('Top connection points') as HTMLInputElement).value).toBe('1')
+    expect((screen.getByLabelText('Bottom connection points') as HTMLInputElement).value).toBe('1')
+    expect((screen.getByLabelText('Left connection points') as HTMLInputElement).value).toBe('0')
+    expect((screen.getByLabelText('Right connection points') as HTMLInputElement).value).toBe('0')
   })
 
-  it('pre-fills bottom_handles from initial', () => {
-    renderModal({ initial: { ...BASE, bottom_handles: 3 } })
-    const slider = screen.getByLabelText('Bottom connection points slider') as HTMLInputElement
-    expect(slider.value).toBe('3')
+  it('pre-fills each side from initial', () => {
+    renderModal({ initial: { ...BASE, top_handles: 2, bottom_handles: 3, left_handles: 4, right_handles: 1 } })
+    expect((screen.getByLabelText('Top connection points') as HTMLInputElement).value).toBe('2')
+    expect((screen.getByLabelText('Bottom connection points') as HTMLInputElement).value).toBe('3')
+    expect((screen.getByLabelText('Left connection points') as HTMLInputElement).value).toBe('4')
+    expect((screen.getByLabelText('Right connection points') as HTMLInputElement).value).toBe('1')
   })
 
-  it('submits updated bottom_handles', () => {
+  it('submits per-side counts edited via the number inputs', () => {
     const { onSubmit } = renderModal({ initial: BASE })
-    const slider = screen.getByLabelText('Bottom connection points slider') as HTMLInputElement
-    fireEvent.change(slider, { target: { value: '12' } })
+    fireEvent.change(screen.getByLabelText('Bottom connection points'), { target: { value: '12' } })
+    fireEvent.change(screen.getByLabelText('Left connection points'), { target: { value: '3' } })
     fireEvent.click(screen.getByRole('button', { name: 'Add' }))
-    expect((onSubmit.mock.calls[0][0] as Partial<NodeData>).bottom_handles).toBe(12)
+    const payload = onSubmit.mock.calls[0][0] as Partial<NodeData>
+    expect(payload.bottom_handles).toBe(12)
+    expect(payload.left_handles).toBe(3)
+    expect(payload.top_handles).toBe(1)
+    expect(payload.right_handles).toBe(0)
   })
 
-  it('supports the full 1..64 range (issue #20)', () => {
+  it('increments a side with the + stepper button', () => {
     const { onSubmit } = renderModal({ initial: BASE })
-    const slider = screen.getByLabelText('Bottom connection points slider') as HTMLInputElement
-    expect(slider.min).toBe('1')
-    expect(slider.max).toBe('64')
-    fireEvent.change(slider, { target: { value: '52' } })
+    fireEvent.click(screen.getByRole('button', { name: 'Increase Right connection points' }))
+    fireEvent.click(screen.getByRole('button', { name: 'Increase Right connection points' }))
+    fireEvent.click(screen.getByRole('button', { name: 'Add' }))
+    expect((onSubmit.mock.calls[0][0] as Partial<NodeData>).right_handles).toBe(2)
+  })
+
+  it('disables the − button at the side minimum (0 for left/right, 1 for top/bottom)', () => {
+    renderModal({ initial: BASE })
+    expect((screen.getByRole('button', { name: 'Decrease Left connection points' }) as HTMLButtonElement).disabled).toBe(true)
+    expect((screen.getByRole('button', { name: 'Decrease Top connection points' }) as HTMLButtonElement).disabled).toBe(true)
+  })
+
+  it('left/right min is 0, top/bottom min is 1; max is 64 everywhere', () => {
+    renderModal({ initial: BASE })
+    expect((screen.getByLabelText('Bottom connection points') as HTMLInputElement).min).toBe('1')
+    expect((screen.getByLabelText('Left connection points') as HTMLInputElement).min).toBe('0')
+    for (const label of ['Top', 'Right', 'Bottom', 'Left']) {
+      expect((screen.getByLabelText(`${label} connection points`) as HTMLInputElement).max).toBe('64')
+    }
+  })
+
+  it('supports the full range up to 64 (issue #20)', () => {
+    const { onSubmit } = renderModal({ initial: BASE })
+    fireEvent.change(screen.getByLabelText('Bottom connection points'), { target: { value: '52' } })
     fireEvent.click(screen.getByRole('button', { name: 'Add' }))
     expect((onSubmit.mock.calls[0][0] as Partial<NodeData>).bottom_handles).toBe(52)
   })
 
-  it('clamps pre-filled out-of-range values into [1,64]', () => {
+  it('clamps pre-filled out-of-range values into range', () => {
     renderModal({ initial: { ...BASE, bottom_handles: 9999 } })
-    const slider = screen.getByLabelText('Bottom connection points slider') as HTMLInputElement
-    expect(slider.value).toBe('64')
+    expect((screen.getByLabelText('Bottom connection points') as HTMLInputElement).value).toBe('64')
   })
 
   it('toggles show_port_numbers and submits it (issue #20)', () => {