fix(workflow): improve node organization

web/app/components/workflow/hooks/__tests__/use-workflow-interactions.spec.tsx

@@ -28,7 +28,7 @@ const mockHandleEdgeCancelRunningStatus = vi.hoisted(() => vi.fn())
 const mockHandleSyncWorkflowDraft = vi.hoisted(() => vi.fn())
 const mockSaveStateToHistory = vi.hoisted(() => vi.fn())
 const mockGetLayoutForChildNodes = vi.hoisted(() => vi.fn())
-const mockGetLayoutByDagre = vi.hoisted(() => vi.fn())
+const mockGetLayoutByELK = vi.hoisted(() => vi.fn())
 const mockInitialNodes = vi.hoisted(() => vi.fn((nodes: unknown[], _edges: unknown[]) => nodes))
 const mockInitialEdges = vi.hoisted(() => vi.fn((edges: unknown[], _nodes: unknown[]) => edges))
 
@@ -112,7 +112,7 @@ vi.mock('../use-workflow-history', () => ({
 vi.mock('../../utils', async importOriginal => ({
   ...(await importOriginal<typeof import('../../utils')>()),
   getLayoutForChildNodes: (...args: unknown[]) => mockGetLayoutForChildNodes(...args),
-  getLayoutByDagre: (...args: unknown[]) => mockGetLayoutByDagre(...args),
+  getLayoutByELK: (...args: unknown[]) => mockGetLayoutByELK(...args),
   initialNodes: (nodes: unknown[], edges: unknown[]) => mockInitialNodes(nodes, edges),
   initialEdges: (edges: unknown[], nodes: unknown[]) => mockInitialEdges(edges, nodes),
 }))
@@ -203,7 +203,7 @@ describe('use-workflow-interactions exports', () => {
         ['loop-child', { x: 40, y: 60, width: 100, height: 60 }],
       ]),
     })
-    mockGetLayoutByDagre.mockResolvedValue({
+    mockGetLayoutByELK.mockResolvedValue({
       nodes: new Map([
         ['loop-node', { x: 10, y: 20, width: 360, height: 260, layer: 0 }],
         ['top-node', { x: 500, y: 30, width: 240, height: 100, layer: 0 }],

web/app/components/workflow/hooks/use-workflow-organize.ts

@@ -2,7 +2,7 @@ import { useCallback } from 'react'
 import { useReactFlow, useStoreApi } from 'reactflow'
 import { useWorkflowStore } from '../store'
 import {
-  getLayoutByDagre,
+  getLayoutByELK,
   getLayoutForChildNodes,
 } from '../utils'
 import { useNodesSyncDraft } from './use-nodes-sync-draft'
@@ -49,7 +49,7 @@ export const useWorkflowOrganize = () => {
       nodes,
       getContainerSizeChanges(parentNodes, childLayoutsMap),
     )
-    const layout = await getLayoutByDagre(nodesWithUpdatedSizes, edges)
+    const layout = await getLayoutByELK(nodesWithUpdatedSizes, edges)
     const nextNodes = applyLayoutToNodes({
       nodes: nodesWithUpdatedSizes,
       layout,

web/app/components/workflow/utils/__tests__/elk-layout.spec.ts

@@ -5,7 +5,7 @@ import { CUSTOM_ITERATION_START_NODE } from '../../nodes/iteration-start/constan
 import { CUSTOM_LOOP_START_NODE } from '../../nodes/loop-start/constants'
 import { BlockEnum } from '../../types'
 
-type ElkChild = Record<string, unknown> & { id: string, width?: number, height?: number, x?: number, y?: number, children?: ElkChild[], ports?: Array<{ id: string }>, layoutOptions?: Record<string, string> }
+type ElkChild = Record<string, unknown> & { id: string, width?: number, height?: number, x?: number, y?: number, children?: ElkChild[], ports?: Array<{ id: string, layoutOptions?: Record<string, string> }>, layoutOptions?: Record<string, string> }
 type ElkGraph = Record<string, unknown> & { id: string, children?: ElkChild[], edges?: Array<Record<string, unknown>> }
 
 let layoutCallArgs: ElkGraph | null = null
@@ -32,7 +32,7 @@ vi.mock('elkjs/lib/elk.bundled.js', () => {
   }
 })
 
-const { getLayoutByDagre, getLayoutForChildNodes } = await import('../elk-layout')
+const { getLayoutByELK, getLayoutForChildNodes } = await import('../elk-layout')
 
 function makeWorkflowNode(overrides: Omit<Partial<Node>, 'data'> & { data?: Partial<CommonNodeType> & Record<string, unknown> } = {}): Node {
   return createNode({
@@ -51,7 +51,7 @@ beforeEach(() => {
   mockReturnOverride = null
 })
 
-describe('getLayoutByDagre', () => {
+describe('getLayoutByELK', () => {
   it('should return layout for simple linear graph', async () => {
     const nodes = [
       makeWorkflowNode({ id: 'a', data: { type: BlockEnum.Start, title: '', desc: '' } }),
@@ -59,7 +59,7 @@ describe('getLayoutByDagre', () => {
     ]
     const edges = [makeWorkflowEdge({ source: 'a', target: 'b' })]
 
-    const result = await getLayoutByDagre(nodes, edges)
+    const result = await getLayoutByELK(nodes, edges)
 
     expect(result.nodes.size).toBe(2)
     expect(result.nodes.has('a')).toBe(true)
@@ -74,7 +74,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowNode({ id: 'child', data: { type: BlockEnum.Code, title: '', desc: '' }, parentId: 'a' }),
     ]
 
-    const result = await getLayoutByDagre(nodes, [])
+    const result = await getLayoutByELK(nodes, [])
     expect(result.nodes.size).toBe(1)
     expect(result.nodes.has('child')).toBe(false)
   })
@@ -85,7 +85,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowNode({ id: 'iter-start', type: CUSTOM_ITERATION_START_NODE, data: { type: BlockEnum.IterationStart, title: '', desc: '' } }),
     ]
 
-    const result = await getLayoutByDagre(nodes, [])
+    const result = await getLayoutByELK(nodes, [])
     expect(result.nodes.size).toBe(1)
   })
 
@@ -98,7 +98,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ source: 'a', target: 'b', data: { isInIteration: true, iteration_id: 'iter-1' } }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     expect(layoutCallArgs!.edges).toHaveLength(0)
   })
 
@@ -107,7 +107,7 @@ describe('getLayoutByDagre', () => {
     Reflect.deleteProperty(node, 'width')
     Reflect.deleteProperty(node, 'height')
 
-    const result = await getLayoutByDagre([node], [])
+    const result = await getLayoutByELK([node], [])
     expect(result.nodes.size).toBe(1)
     const info = result.nodes.get('a')!
     expect(info.width).toBe(244)
@@ -133,13 +133,13 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ id: 'e2', source: 'if-1', target: 'c', sourceHandle: 'false' }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const ifElkNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'if-1')!
     expect(ifElkNode.ports).toHaveLength(2)
     expect(ifElkNode.layoutOptions!['elk.portConstraints']).toBe('FIXED_ORDER')
   })
 
-  it('should use normal node for IfElse with single branch', async () => {
+  it('should build ports for IfElse even with single branch', async () => {
     const nodes = [
       makeWorkflowNode({
         id: 'if-1',
@@ -149,9 +149,10 @@ describe('getLayoutByDagre', () => {
     ]
     const edges = [makeWorkflowEdge({ source: 'if-1', target: 'b', sourceHandle: 'case-1' })]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const ifElkNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'if-1')!
-    expect(ifElkNode.ports).toBeUndefined()
+    expect(ifElkNode.ports).toHaveLength(1)
+    expect(ifElkNode.ports![0].layoutOptions!['elk.port.side']).toBe('EAST')
   })
 
   it('should build ports for HumanInput nodes with multiple branches', async () => {
@@ -168,12 +169,12 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ id: 'e2', source: 'hi-1', target: 'c', sourceHandle: '__timeout' }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const hiElkNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'hi-1')!
     expect(hiElkNode.ports).toHaveLength(2)
   })
 
-  it('should use normal node for HumanInput with single branch', async () => {
+  it('should build ports for HumanInput even with single branch', async () => {
     const nodes = [
       makeWorkflowNode({
         id: 'hi-1',
@@ -183,20 +184,21 @@ describe('getLayoutByDagre', () => {
     ]
     const edges = [makeWorkflowEdge({ source: 'hi-1', target: 'b', sourceHandle: 'action-1' })]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const hiElkNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'hi-1')!
-    expect(hiElkNode.ports).toBeUndefined()
+    expect(hiElkNode.ports).toHaveLength(1)
+    expect(hiElkNode.ports![0].layoutOptions!['elk.port.side']).toBe('EAST')
   })
 
   it('should normalise bounds so minX and minY start at 0', async () => {
     const nodes = [makeWorkflowNode({ id: 'a', data: { type: BlockEnum.Start, title: '', desc: '' } })]
-    const result = await getLayoutByDagre(nodes, [])
+    const result = await getLayoutByELK(nodes, [])
     expect(result.bounds.minX).toBe(0)
     expect(result.bounds.minY).toBe(0)
   })
 
   it('should return empty layout when no nodes match filter', async () => {
-    const result = await getLayoutByDagre([], [])
+    const result = await getLayoutByELK([], [])
     expect(result.nodes.size).toBe(0)
     expect(result.bounds).toEqual({ minX: 0, minY: 0, maxX: 0, maxY: 0 })
   })
@@ -225,7 +227,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ id: 'e-b', source: 'if-1', target: 'y', sourceHandle: 'case-b' }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const ifNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'if-1')!
     const portIds = ifNode.ports!.map((p: { id: string }) => p.id)
     expect(portIds[portIds.length - 1]).toContain('false')
@@ -247,7 +249,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ id: 'e-a2', source: 'hi-1', target: 'y', sourceHandle: 'a2' }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const hiNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'hi-1')!
     const portIds = hiNode.ports!.map((p: { id: string }) => p.id)
     expect(portIds[portIds.length - 1]).toContain('__timeout')
@@ -267,7 +269,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ id: 'e2', source: 'if-1', target: 'c', sourceHandle: 'false' }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const portEdges = layoutCallArgs!.edges!.filter((e: Record<string, unknown>) => e.sourcePort)
     expect(portEdges.length).toBeGreaterThan(0)
   })
@@ -286,7 +288,7 @@ describe('getLayoutByDagre', () => {
     Reflect.deleteProperty(e1, 'sourceHandle')
     Reflect.deleteProperty(e2, 'sourceHandle')
 
-    const result = await getLayoutByDagre(nodes, [e1, e2])
+    const result = await getLayoutByELK(nodes, [e1, e2])
     expect(result.nodes.size).toBeGreaterThan(0)
   })
 
@@ -299,7 +301,7 @@ describe('getLayoutByDagre', () => {
     })
 
     const nodes = [makeWorkflowNode({ id: 'a', data: { type: BlockEnum.Start, title: '', desc: '' } })]
-    const result = await getLayoutByDagre(nodes, [])
+    const result = await getLayoutByELK(nodes, [])
     const info = result.nodes.get('a')!
     expect(info.x).toBe(0)
     expect(info.y).toBe(0)
@@ -326,7 +328,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowNode({ id: 'a', data: { type: BlockEnum.Start, title: '', desc: '' } }),
       makeWorkflowNode({ id: 'b', data: { type: BlockEnum.Code, title: '', desc: '' } }),
     ]
-    const result = await getLayoutByDagre(nodes, [])
+    const result = await getLayoutByELK(nodes, [])
     expect(result.nodes.get('a')!.layer).toBe(0)
     expect(result.nodes.get('b')!.layer).toBe(1)
   })
@@ -354,7 +356,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowNode({ id: 'nested-1', data: { type: BlockEnum.Code, title: '', desc: '' } }),
       makeWorkflowNode({ id: 'nested-2', data: { type: BlockEnum.Code, title: '', desc: '' } }),
     ]
-    const result = await getLayoutByDagre(nodes, [])
+    const result = await getLayoutByELK(nodes, [])
     expect(result.nodes.has('nested-1')).toBe(true)
     expect(result.nodes.has('nested-2')).toBe(true)
   })
@@ -372,7 +374,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowNode({ id: 'visible', data: { type: BlockEnum.Start, title: '', desc: '' } }),
       makeWorkflowNode({ id: 'also-visible', data: { type: BlockEnum.Code, title: '', desc: '' } }),
     ]
-    const result = await getLayoutByDagre(nodes, [])
+    const result = await getLayoutByELK(nodes, [])
     expect(result.nodes.size).toBe(2)
   })
 
@@ -390,7 +392,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ id: 'e2', source: 'if-1', target: 'c', sourceHandle: 'other-unknown' }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const ifNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'if-1')!
     expect(ifNode.ports).toHaveLength(2)
   })
@@ -409,7 +411,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ id: 'e2', source: 'hi-1', target: 'c', sourceHandle: 'another-unknown' }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const hiNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'hi-1')!
     expect(hiNode.ports).toHaveLength(2)
   })
@@ -428,7 +430,7 @@ describe('getLayoutByDagre', () => {
     Reflect.deleteProperty(e1, 'sourceHandle')
     Reflect.deleteProperty(e2, 'sourceHandle')
 
-    await getLayoutByDagre(nodes, [e1, e2])
+    await getLayoutByELK(nodes, [e1, e2])
     const ifNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'if-1')!
     expect(ifNode.ports).toHaveLength(2)
   })
@@ -447,7 +449,7 @@ describe('getLayoutByDagre', () => {
     Reflect.deleteProperty(e1, 'sourceHandle')
     Reflect.deleteProperty(e2, 'sourceHandle')
 
-    await getLayoutByDagre(nodes, [e1, e2])
+    await getLayoutByELK(nodes, [e1, e2])
     const hiNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'hi-1')!
     expect(hiNode.ports).toHaveLength(2)
   })
@@ -463,7 +465,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ id: 'e2', source: 'if-1', target: 'c', sourceHandle: 'false' }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const ifNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'if-1')!
     expect(ifNode.ports).toHaveLength(2)
   })
@@ -479,7 +481,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ id: 'e2', source: 'hi-1', target: 'c', sourceHandle: '__timeout' }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     const hiNode = layoutCallArgs!.children!.find((c: ElkChild) => c.id === 'hi-1')!
     expect(hiNode.ports).toHaveLength(2)
   })
@@ -492,7 +494,7 @@ describe('getLayoutByDagre', () => {
       makeWorkflowEdge({ source: 'x', target: 'y', data: { isInLoop: true, loop_id: 'loop-1' } }),
     ]
 
-    await getLayoutByDagre(nodes, edges)
+    await getLayoutByELK(nodes, edges)
     expect(layoutCallArgs!.edges).toHaveLength(0)
   })
 })

web/app/components/workflow/utils/elk-layout.ts

@@ -18,9 +18,6 @@ import {
   BlockEnum,
 } from '@/app/components/workflow/types'
 
-// Although the file name refers to Dagre, the implementation now relies on ELK's layered algorithm.
-// Keep the export signatures unchanged to minimise the blast radius while we migrate the layout stack.
-
 const elk = new ELK()
 
 const DEFAULT_NODE_WIDTH = 244
@@ -41,7 +38,6 @@ const ROOT_LAYOUT_OPTIONS = {
   // === Port Configuration ===
   'elk.portConstraints': 'FIXED_ORDER',
   'elk.layered.considerModelOrder.strategy': 'PREFER_EDGES',
-  'elk.port.side': 'SOUTH',
 
   // === Node Placement - Best quality ===
   'elk.layered.nodePlacement.strategy': 'NETWORK_SIMPLEX',
@@ -278,32 +274,16 @@ const collectLayout = (graph: ElkNode, predicate: (id: string) => boolean): Layo
   }
 }
 
-/**
- * Build If/Else node with ELK native Ports instead of dummy nodes
- * This is the recommended approach for handling multiple branches
- */
-const buildIfElseWithPorts = (
-  ifElseNode: Node,
-  edges: Edge[],
-): { node: ElkNodeShape, portMap: Map<string, string> } | null => {
-  const childEdges = edges.filter(edge => edge.source === ifElseNode.id)
-
-  if (childEdges.length <= 1)
-    return null
-
-  // Sort child edges according to case order
-  const sortedChildEdges = [...childEdges].sort((edgeA, edgeB) => {
+const sortIfElseOutEdges = (ifElseNode: Node, outEdges: Edge[]): Edge[] => {
+  return [...outEdges].sort((edgeA, edgeB) => {
     const handleA = edgeA.sourceHandle
     const handleB = edgeB.sourceHandle
 
     if (handleA && handleB) {
       const cases = (ifElseNode.data as IfElseNodeType).cases || []
-      const isAElse = handleA === 'false'
-      const isBElse = handleB === 'false'
-
-      if (isAElse)
+      if (handleA === 'false')
         return 1
-      if (isBElse)
+      if (handleB === 'false')
         return -1
 
       const indexA = cases.findIndex((c: CaseItem) => c.case_id === handleA)
@@ -315,67 +295,20 @@ const buildIfElseWithPorts = (
 
     return 0
   })
-
-  // Create ELK ports for each branch
-  const ports: ElkPortShape[] = sortedChildEdges.map((edge, index) => ({
-    id: `${ifElseNode.id}-port-${edge.sourceHandle || index}`,
-    layoutOptions: {
-      'port.side': 'EAST', // Ports on the right side (matching 'RIGHT' direction)
-      'port.index': String(index),
-    },
-  }))
-
-  // Build port mapping: sourceHandle -> portId
-  const portMap = new Map<string, string>()
-  sortedChildEdges.forEach((edge, index) => {
-    const portId = `${ifElseNode.id}-port-${edge.sourceHandle || index}`
-    portMap.set(edge.id, portId)
-  })
-
-  return {
-    node: {
-      id: ifElseNode.id,
-      width: ifElseNode.width ?? DEFAULT_NODE_WIDTH,
-      height: ifElseNode.height ?? DEFAULT_NODE_HEIGHT,
-      ports,
-      layoutOptions: {
-        'elk.portConstraints': 'FIXED_ORDER',
-      },
-    },
-    portMap,
-  }
 }
 
-/**
- * Build Human Input node with ELK native Ports for multiple branches
- * Handles user actions as branches with __timeout as the last fixed branch
- */
-const buildHumanInputWithPorts = (
-  humanInputNode: Node,
-  edges: Edge[],
-): { node: ElkNodeShape, portMap: Map<string, string> } | null => {
-  const childEdges = edges.filter(edge => edge.source === humanInputNode.id)
-
-  if (childEdges.length <= 1)
-    return null
-
-  // Sort child edges: user actions first (by order), then __timeout last
-  const sortedChildEdges = [...childEdges].sort((edgeA, edgeB) => {
+const sortHumanInputOutEdges = (humanInputNode: Node, outEdges: Edge[]): Edge[] => {
+  return [...outEdges].sort((edgeA, edgeB) => {
     const handleA = edgeA.sourceHandle
     const handleB = edgeB.sourceHandle
 
     if (handleA && handleB) {
       const userActions = (humanInputNode.data as HumanInputNodeType).user_actions || []
-      const isATimeout = handleA === '__timeout'
-      const isBTimeout = handleB === '__timeout'
-
-      // __timeout should always be last
-      if (isATimeout)
+      if (handleA === '__timeout')
         return 1
-      if (isBTimeout)
+      if (handleB === '__timeout')
         return -1
 
-      // Sort by user_actions order
       const indexA = userActions.findIndex(action => action.id === handleA)
       const indexB = userActions.findIndex(action => action.id === handleB)
 
@@ -385,35 +318,6 @@ const buildHumanInputWithPorts = (
 
     return 0
   })
-
-  // Create ELK ports for each branch
-  const ports: ElkPortShape[] = sortedChildEdges.map((edge, index) => ({
-    id: `${humanInputNode.id}-port-${edge.sourceHandle || index}`,
-    layoutOptions: {
-      'port.side': 'EAST',
-      'port.index': String(index),
-    },
-  }))
-
-  // Build port mapping: edge.id -> portId
-  const portMap = new Map<string, string>()
-  sortedChildEdges.forEach((edge, index) => {
-    const portId = `${humanInputNode.id}-port-${edge.sourceHandle || index}`
-    portMap.set(edge.id, portId)
-  })
-
-  return {
-    node: {
-      id: humanInputNode.id,
-      width: humanInputNode.width ?? DEFAULT_NODE_WIDTH,
-      height: humanInputNode.height ?? DEFAULT_NODE_HEIGHT,
-      ports,
-      layoutOptions: {
-        'elk.portConstraints': 'FIXED_ORDER',
-      },
-    },
-    portMap,
-  }
 }
 
 const normaliseBounds = (layout: LayoutResult): LayoutResult => {
@@ -448,58 +352,87 @@ const normaliseBounds = (layout: LayoutResult): LayoutResult => {
   }
 }
 
-export const getLayoutByDagre = async (originNodes: Node[], originEdges: Edge[]): Promise<LayoutResult> => {
+export const getLayoutByELK = async (originNodes: Node[], originEdges: Edge[]): Promise<LayoutResult> => {
   edgeCounter = 0
   const nodes = cloneDeep(originNodes).filter(node => !node.parentId && node.type === CUSTOM_NODE)
   const edges = cloneDeep(originEdges).filter(edge => (!edge.data?.isInIteration && !edge.data?.isInLoop))
 
-  const elkNodes: ElkNodeShape[] = []
-  const elkEdges: ElkEdgeShape[] = []
-
-  // Track which edges have been processed for If/Else nodes with ports
-  const edgeToPortMap = new Map<string, string>()
-
-  // Build nodes with ports for If/Else and Human Input nodes
-  nodes.forEach((node) => {
-    if (node.data.type === BlockEnum.IfElse) {
-      const portsResult = buildIfElseWithPorts(node, edges)
-      if (portsResult) {
-        // Use node with ports
-        elkNodes.push(portsResult.node)
-        // Store port mappings for edges
-        portsResult.portMap.forEach((portId, edgeId) => {
-          edgeToPortMap.set(edgeId, portId)
-        })
-      }
-      else {
-        // No multiple branches, use normal node
-        elkNodes.push(toElkNode(node))
-      }
-    }
-    else if (node.data.type === BlockEnum.HumanInput) {
-      const portsResult = buildHumanInputWithPorts(node, edges)
-      if (portsResult) {
-        // Use node with ports
-        elkNodes.push(portsResult.node)
-        // Store port mappings for edges
-        portsResult.portMap.forEach((portId, edgeId) => {
-          edgeToPortMap.set(edgeId, portId)
-        })
-      }
-      else {
-        // No multiple branches, use normal node
-        elkNodes.push(toElkNode(node))
-      }
-    }
-    else {
-      elkNodes.push(toElkNode(node))
-    }
+  const outEdgesByNode = new Map<string, Edge[]>()
+  const inEdgesByNode = new Map<string, Edge[]>()
+  edges.forEach((edge) => {
+    if (!outEdgesByNode.has(edge.source))
+      outEdgesByNode.set(edge.source, [])
+    outEdgesByNode.get(edge.source)!.push(edge)
+    if (!inEdgesByNode.has(edge.target))
+      inEdgesByNode.set(edge.target, [])
+    inEdgesByNode.get(edge.target)!.push(edge)
   })
 
-  // Build edges with port connections
-  edges.forEach((edge) => {
-    const sourcePort = edgeToPortMap.get(edge.id)
-    elkEdges.push(createEdge(edge.source, edge.target, sourcePort))
+  const elkNodes: ElkNodeShape[] = []
+  const elkEdges: ElkEdgeShape[] = []
+  const sourcePortMap = new Map<string, string>()
+  const targetPortMap = new Map<string, string>()
+  const sortedOutEdgesByNode = new Map<string, Edge[]>()
+
+  nodes.forEach((node) => {
+    const inEdges = inEdgesByNode.get(node.id) || []
+    let outEdges = outEdgesByNode.get(node.id) || []
+
+    if (node.data.type === BlockEnum.IfElse)
+      outEdges = sortIfElseOutEdges(node, outEdges)
+    else if (node.data.type === BlockEnum.HumanInput)
+      outEdges = sortHumanInputOutEdges(node, outEdges)
+
+    sortedOutEdgesByNode.set(node.id, outEdges)
+
+    const ports: ElkPortShape[] = []
+
+    inEdges.forEach((edge, index) => {
+      const portId = `${node.id}-in-${index}`
+      ports.push({
+        id: portId,
+        layoutOptions: {
+          'elk.port.side': 'WEST',
+          'elk.port.index': String(index),
+        },
+      })
+      targetPortMap.set(edge.id, portId)
+    })
+
+    outEdges.forEach((edge, index) => {
+      const portId = `${node.id}-out-${edge.sourceHandle || index}`
+      ports.push({
+        id: portId,
+        layoutOptions: {
+          'elk.port.side': 'EAST',
+          'elk.port.index': String(index),
+        },
+      })
+      sourcePortMap.set(edge.id, portId)
+    })
+
+    elkNodes.push({
+      id: node.id,
+      width: node.width ?? DEFAULT_NODE_WIDTH,
+      height: node.height ?? DEFAULT_NODE_HEIGHT,
+      ...(ports.length > 0 && {
+        ports,
+        layoutOptions: { 'elk.portConstraints': 'FIXED_ORDER' },
+      }),
+    })
+  })
+
+  // Build edges in sorted per-node order so PREFER_EDGES aligns with port order
+  nodes.forEach((node) => {
+    const outEdges = sortedOutEdgesByNode.get(node.id) || []
+    outEdges.forEach((edge) => {
+      elkEdges.push(createEdge(
+        edge.source,
+        edge.target,
+        sourcePortMap.get(edge.id),
+        targetPortMap.get(edge.id),
+      ))
+    })
   })
 
   const graph = {