feat: add YAML import — merge nodes/edges from .yaml file into canvas

feat: YAML export

frontend/package-lock.json

@@ -13,12 +13,14 @@
         "@fontsource-variable/geist": "^5.2.8",
         "@fontsource-variable/inter": "^5.2.8",
         "@fontsource/jetbrains-mono": "^5.2.8",
+        "@types/js-yaml": "^4.0.9",
         "@xyflow/react": "^12.10.1",
         "axios": "^1.13.6",
         "class-variance-authority": "^0.7.1",
         "clsx": "^2.1.1",
         "dagre": "^0.8.5",
         "html-to-image": "^1.11.13",
+        "js-yaml": "^4.1.1",
         "next-themes": "^0.4.6",
         "react": "^19.2.0",
         "react-dom": "^19.2.0",
@@ -3008,6 +3010,12 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@types/js-yaml": {
+      "version": "4.0.9",
+      "resolved": "https://registry.npmjs.org/@types/js-yaml/-/js-yaml-4.0.9.tgz",
+      "integrity": "sha512-k4MGaQl5TGo/iipqb2UDG2UwjXziSWkh0uysQelTlJpX1qGlpUZYm8PnO4DxG1qBomtJUdYJ6qR6xdIah10JLg==",
+      "license": "MIT"
+    },
     "node_modules/@types/json-schema": {
       "version": "7.0.15",
       "resolved": "https://registry.npmjs.org/@types/json-schema/-/json-schema-7.0.15.tgz",

frontend/package.json

@@ -19,12 +19,14 @@
     "@fontsource-variable/geist": "^5.2.8",
     "@fontsource-variable/inter": "^5.2.8",
     "@fontsource/jetbrains-mono": "^5.2.8",
+    "@types/js-yaml": "^4.0.9",
     "@xyflow/react": "^12.10.1",
     "axios": "^1.13.6",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "dagre": "^0.8.5",
     "html-to-image": "^1.11.13",
+    "js-yaml": "^4.1.1",
     "next-themes": "^0.4.6",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",

frontend/src/App.tsx

@@ -5,6 +5,8 @@ import { applyDagreLayout } from '@/utils/layout'
 import { generateUUID } from '@/utils/uuid'
 import { generateMarkdownTable } from '@/utils/exportMarkdown'
 import { exportToPng } from '@/utils/export'
+import { exportCanvasToYaml, downloadYaml } from '@/utils/exportYaml'
+import { parseYamlToCanvas } from '@/utils/importYaml'
 import { TooltipProvider } from '@/components/ui/tooltip'
 import { Toaster } from '@/components/ui/sonner'
 import { toast } from 'sonner'
@@ -32,7 +34,7 @@ const STANDALONE = import.meta.env.VITE_STANDALONE === 'true'
 const STANDALONE_STORAGE_KEY = 'homelable_canvas'
 
 export default function App() {
-  const { loadCanvas, markSaved, selectedNodeId, addNode, updateNode, deleteNode, onConnect, updateEdge, deleteEdge, setProxmoxContainerMode, setNodeZIndex, editingGroupRectId, setEditingGroupRectId, nodes, edges, snapshotHistory, undo, redo, copySelectedNodes, pasteNodes } = useCanvasStore()
+  const { loadCanvas, markSaved, markUnsaved, selectedNodeId, addNode, updateNode, deleteNode, onConnect, updateEdge, deleteEdge, setProxmoxContainerMode, setNodeZIndex, editingGroupRectId, setEditingGroupRectId, nodes, edges, snapshotHistory, undo, redo, copySelectedNodes, pasteNodes } = useCanvasStore()
   const canvasRef = useRef<HTMLDivElement>(null)
   const { isAuthenticated } = useAuthStore()
   const { activeTheme, setTheme } = useThemeStore()
@@ -371,6 +373,25 @@ export default function App() {
     toast.success('Markdown table copied to clipboard')
   }, [nodes])
 
+  const handleExportYaml = useCallback(() => {
+    if (nodes.length === 0) { toast.error('No nodes to export'); return }
+    const content = exportCanvasToYaml(nodes, edges)
+    downloadYaml(content)
+    toast.success('Canvas exported as YAML')
+  }, [nodes, edges])
+
+  const handleImportYaml = useCallback((content: string) => {
+    try {
+      const { nodes: merged, edges: mergedEdges, imported } = parseYamlToCanvas(content, nodes, edges)
+      snapshotHistory()
+      loadCanvas(merged, mergedEdges)
+      markUnsaved()
+      toast.success(`Imported ${imported} node${imported !== 1 ? 's' : ''}`)
+    } catch (err) {
+      toast.error(`Import failed: ${err instanceof Error ? err.message : String(err)}`)
+    }
+  }, [nodes, edges, snapshotHistory, loadCanvas, markUnsaved])
+
   const handleExport = useCallback(async () => {
     const el = canvasRef.current?.querySelector<HTMLElement>('.react-flow')
     if (!el) { toast.error('Canvas not ready'); return }
@@ -449,6 +470,8 @@ export default function App() {
               onRedo={redo}
               onShortcuts={() => setShortcutsOpen(true)}
               onExportMd={handleExportMd}
+              onExportYaml={handleExportYaml}
+              onImportYaml={handleImportYaml}
             />
             <div className="flex flex-1 min-h-0">
               <div ref={canvasRef} className="flex-1 min-w-0 h-full">

frontend/src/components/panels/Toolbar.tsx

@@ -1,4 +1,5 @@
-import { Save, LayoutDashboard, Download, Palette, Undo2, Redo2, HelpCircle, Table2 } from 'lucide-react'
+import { useRef } from 'react'
+import { Save, LayoutDashboard, Download, Palette, Undo2, Redo2, HelpCircle, Table2, FileDown, Upload } from 'lucide-react'
 import { Button } from '@/components/ui/button'
 import { Logo } from '@/components/ui/Logo'
 import { useCanvasStore } from '@/stores/canvasStore'
@@ -12,10 +13,25 @@ interface ToolbarProps {
   onRedo: () => void
   onShortcuts: () => void
   onExportMd: () => void
+  onExportYaml: () => void
+  onImportYaml: (content: string) => void
 }
 
-export function Toolbar({ onSave, onAutoLayout, onExport, onChangeStyle, onUndo, onRedo, onShortcuts, onExportMd }: ToolbarProps) {
+export function Toolbar({ onSave, onAutoLayout, onExport, onChangeStyle, onUndo, onRedo, onShortcuts, onExportMd, onExportYaml, onImportYaml }: ToolbarProps) {
   const { hasUnsavedChanges, past, future } = useCanvasStore()
+  const fileInputRef = useRef<HTMLInputElement>(null)
+
+  function handleFileChange(e: React.ChangeEvent<HTMLInputElement>) {
+    const file = e.target.files?.[0]
+    if (!file) return
+    const reader = new FileReader()
+    reader.onload = (ev) => {
+      const content = ev.target?.result
+      if (typeof content === 'string') onImportYaml(content)
+    }
+    reader.readAsText(file)
+    e.target.value = ''
+  }
 
   return (
     <header className="flex items-center gap-2 px-4 py-2 border-b border-border bg-[#161b22] shrink-0">
@@ -46,12 +62,25 @@ export function Toolbar({ onSave, onAutoLayout, onExport, onChangeStyle, onUndo,
       <Button size="sm" variant="ghost" className="gap-1.5 text-muted-foreground hover:text-foreground" onClick={onChangeStyle}>
         <Palette size={14} /> Style
       </Button>
+      <Button size="sm" variant="ghost" className="gap-1.5 text-muted-foreground hover:text-foreground" onClick={() => fileInputRef.current?.click()} title="Import from YAML">
+        <Upload size={14} /> Import
+      </Button>
+      <input
+        ref={fileInputRef}
+        type="file"
+        accept=".yaml,.yml"
+        className="hidden"
+        onChange={handleFileChange}
+      />
       <Button size="sm" variant="ghost" className="gap-1.5 text-muted-foreground hover:text-foreground" onClick={onExport} title="Export as PNG">
         <Download size={14} /> Export
       </Button>
       <Button size="sm" variant="ghost" className="gap-1.5 text-muted-foreground hover:text-foreground" onClick={onExportMd} title="Copy inventory as Markdown table">
         <Table2 size={14} /> MD
       </Button>
+      <Button size="sm" variant="ghost" className="gap-1.5 text-muted-foreground hover:text-foreground" onClick={onExportYaml} title="Export canvas as YAML">
+        <FileDown size={14} /> YAML
+      </Button>
       <Button size="sm" variant="ghost" className="gap-1.5 text-muted-foreground hover:text-foreground" onClick={onShortcuts} title="Keyboard shortcuts (?)">
         <HelpCircle size={14} />
       </Button>

frontend/src/types/yaml.ts

@@ -0,0 +1,25 @@
+import type { NodeType, EdgeType, CheckMethod } from '@/types'
+
+export interface YamlNodeConnection {
+  label: string
+  linkType?: EdgeType
+  linkLabel?: string
+}
+
+export interface YamlNode {
+  nodeType: NodeType
+  nodeIcon?: string
+  label: string
+  hostname?: string
+  ipAddress?: string
+  checkMethod?: CheckMethod
+  checkTarget?: string
+  notes?: string
+  parent?: YamlNodeConnection
+  clusterR?: YamlNodeConnection
+  clusterL?: YamlNodeConnection
+  cpuModel?: string
+  cpuCore?: number
+  ram?: number
+  disk?: number
+}

frontend/src/utils/__tests__/exportYaml.test.ts

@@ -0,0 +1,130 @@
+import { describe, it, expect } from 'vitest'
+import { exportCanvasToYaml } from '../exportYaml'
+import type { Node, Edge } from '@xyflow/react'
+import type { NodeData, EdgeData } from '@/types'
+import yaml from 'js-yaml'
+
+const makeNode = (overrides: Partial<NodeData> = {}, id = '1', parentId?: string): Node<NodeData> => ({
+  id,
+  type: overrides.type ?? 'server',
+  position: { x: 0, y: 0 },
+  parentId,
+  data: { label: 'Test', type: 'server', status: 'online', services: [], ...overrides },
+})
+
+const makeEdge = (id: string, source: string, target: string, data: Partial<EdgeData> = {}): Edge<EdgeData> => ({
+  id,
+  source,
+  target,
+  data: { type: 'ethernet', ...data } as EdgeData,
+})
+
+describe('exportCanvasToYaml', () => {
+  it('serializes a simple node with basic fields', () => {
+    const nodes = [makeNode({ label: 'My Server', type: 'server', ip: '192.168.1.10', hostname: 'srv.local' })]
+    const result = yaml.load(exportCanvasToYaml(nodes, [])) as object[]
+    expect(result).toHaveLength(1)
+    const entry = result[0] as Record<string, unknown>
+    expect(entry.nodeType).toBe('server')
+    expect(entry.label).toBe('My Server')
+    expect(entry.ipAddress).toBe('192.168.1.10')
+    expect(entry.hostname).toBe('srv.local')
+  })
+
+  it('omits empty/null/undefined optional fields', () => {
+    const nodes = [makeNode({ label: 'Router', type: 'router', hostname: undefined, ip: undefined, notes: undefined })]
+    const result = yaml.load(exportCanvasToYaml(nodes, [])) as object[]
+    const entry = result[0] as Record<string, unknown>
+    expect(entry).not.toHaveProperty('hostname')
+    expect(entry).not.toHaveProperty('ipAddress')
+    expect(entry).not.toHaveProperty('notes')
+  })
+
+  it('omits hardware specs when zero or falsy', () => {
+    const nodes = [makeNode({ label: 'Server', type: 'server', cpu_count: 0, ram_gb: 0, disk_gb: 0 })]
+    const result = yaml.load(exportCanvasToYaml(nodes, [])) as object[]
+    const entry = result[0] as Record<string, unknown>
+    expect(entry).not.toHaveProperty('cpuCore')
+    expect(entry).not.toHaveProperty('ram')
+    expect(entry).not.toHaveProperty('disk')
+  })
+
+  it('includes hardware specs when non-zero', () => {
+    const nodes = [makeNode({ label: 'Server', type: 'server', cpu_count: 16, ram_gb: 64, disk_gb: 2000, cpu_model: 'Intel Xeon' })]
+    const result = yaml.load(exportCanvasToYaml(nodes, [])) as object[]
+    const entry = result[0] as Record<string, unknown>
+    expect(entry.cpuCore).toBe(16)
+    expect(entry.ram).toBe(64)
+    expect(entry.disk).toBe(2000)
+    expect(entry.cpuModel).toBe('Intel Xeon')
+  })
+
+  it('serializes parent relationship from parentId', () => {
+    const parent = makeNode({ label: 'Proxmox1', type: 'proxmox' }, 'pve1')
+    const child = makeNode({ label: 'VM1', type: 'vm' }, 'vm1', 'pve1')
+    const edge = makeEdge('e1', 'pve1', 'vm1', { type: 'virtual' })
+    const result = yaml.load(exportCanvasToYaml([parent, child], [edge])) as object[]
+    const childEntry = (result as Record<string, unknown>[]).find((e) => e.label === 'VM1')!
+    expect(childEntry.parent).toEqual({ label: 'Proxmox1', linkType: 'virtual', linkLabel: '' })
+  })
+
+  it('serializes clusterR edge on source node', () => {
+    const nodeA = makeNode({ label: 'NodeA', type: 'proxmox' }, 'a')
+    const nodeB = makeNode({ label: 'NodeB', type: 'proxmox' }, 'b')
+    const edge = makeEdge('e1', 'a', 'b', { type: 'ethernet', label: '10GbE' })
+    const result = yaml.load(exportCanvasToYaml([nodeA, nodeB], [edge])) as Record<string, unknown>[]
+    const entryA = result.find((e) => e.label === 'NodeA')!
+    expect(entryA.clusterR).toEqual({ label: 'NodeB', linkType: 'ethernet', linkLabel: '10GbE' })
+  })
+
+  it('does not duplicate an edge as both clusterR and clusterL', () => {
+    const nodeA = makeNode({ label: 'NodeA', type: 'proxmox' }, 'a')
+    const nodeB = makeNode({ label: 'NodeB', type: 'proxmox' }, 'b')
+    const edge = makeEdge('e1', 'a', 'b', { type: 'ethernet' })
+    const result = yaml.load(exportCanvasToYaml([nodeA, nodeB], [edge])) as Record<string, unknown>[]
+    const entryA = result.find((e) => e.label === 'NodeA')!
+    const entryB = result.find((e) => e.label === 'NodeB')!
+    // clusterR on A and clusterL on B would duplicate — only one side should have it
+    const hasClusterR = 'clusterR' in entryA
+    const hasClusterL = 'clusterL' in entryB
+    expect(hasClusterR && hasClusterL).toBe(false)
+  })
+
+  it('excludes groupRect nodes from output', () => {
+    const nodes = [
+      makeNode({ label: 'Zone', type: 'groupRect' }, '1'),
+      makeNode({ label: 'Server', type: 'server' }, '2'),
+    ]
+    const result = yaml.load(exportCanvasToYaml(nodes, [])) as object[]
+    expect(result).toHaveLength(1)
+    expect((result[0] as Record<string, unknown>).label).toBe('Server')
+  })
+
+  it('roundtrip: all non-empty fields appear in YAML output', () => {
+    const nodes = [makeNode({
+      label: 'Full Node',
+      type: 'server',
+      ip: '10.0.0.1',
+      hostname: 'full.local',
+      check_method: 'ping',
+      check_target: '10.0.0.1',
+      notes: 'test notes',
+      cpu_model: 'AMD EPYC',
+      cpu_count: 32,
+      ram_gb: 128,
+      disk_gb: 4000,
+      custom_icon: 'star',
+    })]
+    const yamlStr = exportCanvasToYaml(nodes, [])
+    expect(yamlStr).toContain('Full Node')
+    expect(yamlStr).toContain('10.0.0.1')
+    expect(yamlStr).toContain('full.local')
+    expect(yamlStr).toContain('ping')
+    expect(yamlStr).toContain('test notes')
+    expect(yamlStr).toContain('AMD EPYC')
+    expect(yamlStr).toContain('32')
+    expect(yamlStr).toContain('128')
+    expect(yamlStr).toContain('4000')
+    expect(yamlStr).toContain('star')
+  })
+})

frontend/src/utils/__tests__/importYaml.test.ts

@@ -0,0 +1,230 @@
+import { describe, it, expect, vi } from 'vitest'
+import { parseYamlToCanvas } from '../importYaml'
+import type { Node, Edge } from '@xyflow/react'
+import type { NodeData, EdgeData } from '@/types'
+
+// Mock dagre layout to return nodes with predictable positions
+vi.mock('../layout', () => ({
+  applyDagreLayout: (nodes: Node<NodeData>[]) =>
+    nodes.map((n, i) => ({ ...n, position: { x: i * 200, y: 0 } })),
+}))
+
+// Mock uuid to return deterministic ids
+let uuidCounter = 0
+vi.mock('../uuid', () => ({
+  generateUUID: () => `test-uuid-${++uuidCounter}`,
+}))
+
+beforeEach(() => {
+  uuidCounter = 0
+})
+
+const empty: Node<NodeData>[] = []
+const emptyEdges: Edge<EdgeData>[] = []
+
+describe('parseYamlToCanvas', () => {
+  it('parses a minimal node (only nodeType + label)', () => {
+    const yaml = `
+- nodeType: server
+  label: "My Server"
+`
+    const { nodes, edges, imported } = parseYamlToCanvas(yaml, empty, emptyEdges)
+    expect(imported).toBe(1)
+    expect(nodes).toHaveLength(1)
+    expect(nodes[0].data.label).toBe('My Server')
+    expect(nodes[0].data.type).toBe('server')
+    expect(nodes[0].data.status).toBe('unknown')
+    expect(edges).toHaveLength(0)
+  })
+
+  it('parses all scalar fields', () => {
+    const yaml = `
+- nodeType: proxmox
+  label: "PVE1"
+  hostname: "pve1.local"
+  ipAddress: "192.168.1.10"
+  checkMethod: ping
+  checkTarget: "192.168.1.10"
+  notes: "main host"
+  nodeIcon: "custom-icon"
+  cpuModel: "Intel Xeon"
+  cpuCore: 16
+  ram: 64
+  disk: 2000
+`
+    const { nodes } = parseYamlToCanvas(yaml, empty, emptyEdges)
+    const d = nodes[0].data
+    expect(d.hostname).toBe('pve1.local')
+    expect(d.ip).toBe('192.168.1.10')
+    expect(d.check_method).toBe('ping')
+    expect(d.check_target).toBe('192.168.1.10')
+    expect(d.notes).toBe('main host')
+    expect(d.custom_icon).toBe('custom-icon')
+    expect(d.cpu_model).toBe('Intel Xeon')
+    expect(d.cpu_count).toBe(16)
+    expect(d.ram_gb).toBe(64)
+    expect(d.disk_gb).toBe(2000)
+    expect(d.show_hardware).toBe(true)
+  })
+
+  it('sets show_hardware only when hardware fields present', () => {
+    const yaml = `- nodeType: server\n  label: "NoHW"\n`
+    const { nodes } = parseYamlToCanvas(yaml, empty, emptyEdges)
+    expect(nodes[0].data.show_hardware).toBeUndefined()
+  })
+
+  it('parent relationship sets parentId and creates an edge', () => {
+    const yaml = `
+- nodeType: proxmox
+  label: "PVE1"
+- nodeType: vm
+  label: "VM1"
+  parent:
+    label: "PVE1"
+    linkType: virtual
+    linkLabel: "hosted"
+`
+    const { nodes, edges } = parseYamlToCanvas(yaml, empty, emptyEdges)
+    const vm = nodes.find((n) => n.data.label === 'VM1')!
+    const pve = nodes.find((n) => n.data.label === 'PVE1')!
+    expect(vm.parentId).toBe(pve.id)
+    expect(vm.data.parent_id).toBe(pve.id)
+    expect(vm.extent).toBe('parent')
+    expect(edges).toHaveLength(1)
+    expect(edges[0].source).toBe(pve.id)
+    expect(edges[0].target).toBe(vm.id)
+    expect(edges[0].type).toBe('virtual')
+    expect(edges[0].data?.label).toBe('hosted')
+  })
+
+  it('clusterR creates an edge from this node to target', () => {
+    const yaml = `
+- nodeType: proxmox
+  label: "PVE1"
+  clusterR:
+    label: "PVE2"
+    linkType: ethernet
+    linkLabel: "10GbE"
+- nodeType: proxmox
+  label: "PVE2"
+`
+    const { nodes, edges } = parseYamlToCanvas(yaml, empty, emptyEdges)
+    const pve1 = nodes.find((n) => n.data.label === 'PVE1')!
+    const pve2 = nodes.find((n) => n.data.label === 'PVE2')!
+    expect(edges).toHaveLength(1)
+    expect(edges[0].source).toBe(pve1.id)
+    expect(edges[0].target).toBe(pve2.id)
+    expect(edges[0].type).toBe('ethernet')
+  })
+
+  it('clusterL creates an edge from referenced node to this node', () => {
+    const yaml = `
+- nodeType: proxmox
+  label: "PVE1"
+- nodeType: proxmox
+  label: "PVE2"
+  clusterL:
+    label: "PVE1"
+    linkType: cluster
+    linkLabel: ""
+`
+    const { nodes, edges } = parseYamlToCanvas(yaml, empty, emptyEdges)
+    const pve1 = nodes.find((n) => n.data.label === 'PVE1')!
+    const pve2 = nodes.find((n) => n.data.label === 'PVE2')!
+    expect(edges).toHaveLength(1)
+    expect(edges[0].source).toBe(pve1.id)
+    expect(edges[0].target).toBe(pve2.id)
+  })
+
+  it('deduplicates edges when clusterR on A and clusterL on B point to each other', () => {
+    const yaml = `
+- nodeType: proxmox
+  label: "PVE1"
+  clusterR:
+    label: "PVE2"
+    linkType: ethernet
+- nodeType: proxmox
+  label: "PVE2"
+  clusterL:
+    label: "PVE1"
+    linkType: ethernet
+`
+    const { edges } = parseYamlToCanvas(yaml, empty, emptyEdges)
+    expect(edges).toHaveLength(1)
+  })
+
+  it('skips nodes with same label as existing canvas nodes', () => {
+    const existing: Node<NodeData>[] = [{
+      id: 'existing-1',
+      type: 'server',
+      position: { x: 0, y: 0 },
+      data: { label: 'ExistingServer', type: 'server', status: 'online', services: [] },
+    }]
+    const yaml = `
+- nodeType: server
+  label: "ExistingServer"
+- nodeType: router
+  label: "NewRouter"
+`
+    const { nodes, imported } = parseYamlToCanvas(yaml, existing, emptyEdges)
+    expect(imported).toBe(1)
+    expect(nodes.filter((n) => n.data.label === 'ExistingServer')).toHaveLength(1)
+    expect(nodes.filter((n) => n.data.label === 'NewRouter')).toHaveLength(1)
+  })
+
+  it('merges with existing edges without duplicating', () => {
+    const existing: Node<NodeData>[] = [
+      { id: 'a', type: 'server', position: { x: 0, y: 0 }, data: { label: 'A', type: 'server', status: 'online', services: [] } },
+      { id: 'b', type: 'server', position: { x: 0, y: 0 }, data: { label: 'B', type: 'server', status: 'online', services: [] } },
+    ]
+    const existingEdge: Edge<EdgeData>[] = [{
+      id: 'e1', source: 'a', target: 'b', type: 'ethernet',
+      data: { type: 'ethernet' },
+    }]
+    const yaml = `
+- nodeType: server
+  label: "A"
+  clusterR:
+    label: "B"
+    linkType: ethernet
+`
+    // A already exists so it's skipped, no new edge created
+    const { edges } = parseYamlToCanvas(yaml, existing, existingEdge)
+    expect(edges).toHaveLength(1)
+  })
+
+  it('throws on invalid YAML', () => {
+    expect(() => parseYamlToCanvas('{invalid: [yaml', empty, emptyEdges)).toThrow()
+  })
+
+  it('throws when YAML is not an array', () => {
+    const yaml = `nodeType: server\nlabel: oops\n`
+    expect(() => parseYamlToCanvas(yaml, empty, emptyEdges)).toThrow(/list/)
+  })
+
+  it('throws when nodeType is missing', () => {
+    const yaml = `- label: "Missing type"\n`
+    expect(() => parseYamlToCanvas(yaml, empty, emptyEdges)).toThrow(/nodeType/)
+  })
+
+  it('throws when label is missing', () => {
+    const yaml = `- nodeType: server\n`
+    expect(() => parseYamlToCanvas(yaml, empty, emptyEdges)).toThrow(/label/)
+  })
+
+  it('warns and skips unknown parent label without crashing', () => {
+    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {})
+    const yaml = `
+- nodeType: vm
+  label: "OrphanVM"
+  parent:
+    label: "NonexistentHost"
+    linkType: virtual
+`
+    const { nodes, edges } = parseYamlToCanvas(yaml, empty, emptyEdges)
+    expect(nodes).toHaveLength(1)
+    expect(edges).toHaveLength(0)
+    expect(warnSpy).toHaveBeenCalledWith(expect.stringContaining('NonexistentHost'))
+    warnSpy.mockRestore()
+  })
+})

frontend/src/utils/exportYaml.ts

@@ -0,0 +1,136 @@
+import type { Node, Edge } from '@xyflow/react'
+import type { NodeData, EdgeData, EdgeType } from '@/types'
+import type { YamlNode, YamlNodeConnection } from '@/types/yaml'
+import yaml from 'js-yaml'
+
+/** Build a map of node id → label for edge resolution */
+function buildIdToLabel(nodes: Node<NodeData>[]): Map<string, string> {
+  const m = new Map<string, string>()
+  for (const n of nodes) m.set(n.id, n.data.label)
+  return m
+}
+
+function makeConnection(targetLabel: string, edgeType: EdgeType, edgeLabel: string | undefined): YamlNodeConnection {
+  return {
+    label: targetLabel,
+    linkType: edgeType,
+    linkLabel: edgeLabel ?? '',
+  }
+}
+
+/**
+ * Serialize React Flow canvas state to a YAML string.
+ * Each node becomes one entry; edges are embedded as parent/clusterR/clusterL sub-objects.
+ * Edge deduplication: each edge is written on exactly one side (source as clusterR, target as clusterL)
+ * unless the edge type is 'virtual' or there is a parentId relationship, in which case
+ * it becomes the 'parent' field of the child node.
+ */
+export function exportCanvasToYaml(nodes: Node<NodeData>[], edges: Edge<EdgeData>[]): string {
+  const idToLabel = buildIdToLabel(nodes)
+
+  // Build per-node edge maps (id → connections)
+  // We use a Set to track already-serialized edge ids (deduplication).
+  const serializedEdges = new Set<string>()
+
+  // Index edges by source and target for quick lookup
+  const edgesBySource = new Map<string, Edge<EdgeData>[]>()
+  const edgesByTarget = new Map<string, Edge<EdgeData>[]>()
+  for (const e of edges) {
+    if (!edgesBySource.has(e.source)) edgesBySource.set(e.source, [])
+    edgesBySource.get(e.source)!.push(e)
+    if (!edgesByTarget.has(e.target)) edgesByTarget.set(e.target, [])
+    edgesByTarget.get(e.target)!.push(e)
+  }
+
+  const yamlNodes: YamlNode[] = []
+
+  for (const node of nodes) {
+    const d = node.data
+
+    // Skip groupRect nodes — they are canvas decoration only
+    if (d.type === 'groupRect') continue
+
+    const entry: YamlNode = {
+      nodeType: d.type,
+      label: d.label,
+    }
+
+    if (d.custom_icon) entry.nodeIcon = d.custom_icon
+    if (d.hostname) entry.hostname = d.hostname
+    if (d.ip) entry.ipAddress = d.ip
+    if (d.check_method && d.check_method !== 'none') entry.checkMethod = d.check_method
+    if (d.check_target) entry.checkTarget = d.check_target
+    if (d.notes) entry.notes = d.notes
+
+    // Hardware specs — omit zero values
+    if (d.cpu_model) entry.cpuModel = d.cpu_model
+    if (d.cpu_count && d.cpu_count > 0) entry.cpuCore = d.cpu_count
+    if (d.ram_gb && d.ram_gb > 0) entry.ram = d.ram_gb
+    if (d.disk_gb && d.disk_gb > 0) entry.disk = d.disk_gb
+
+    // Parent relationship: if this node has a parentId in React Flow,
+    // encode it as a 'parent' connection using any virtual edge between them.
+    if (node.parentId) {
+      const parentLabel = idToLabel.get(node.parentId) ?? node.parentId
+      // Find an edge between parent and this node (either direction)
+      const parentEdges = [
+        ...(edgesBySource.get(node.parentId) ?? []).filter((e) => e.target === node.id),
+        ...(edgesByTarget.get(node.parentId) ?? []).filter((e) => e.source === node.id),
+      ]
+      const pEdge = parentEdges[0]
+      const linkType: EdgeType = (pEdge?.data?.type as EdgeType) ?? 'virtual'
+      const linkLabel = pEdge?.data?.label ?? ''
+      entry.parent = { label: parentLabel, linkType, linkLabel: linkLabel as string }
+      if (pEdge) serializedEdges.add(pEdge.id)
+    }
+
+    // Non-parent edges: serialize as clusterR (source side) or clusterL (target side).
+    // We process source edges as clusterR on this node; target edges as clusterL on this node,
+    // but only if the edge hasn't been serialized yet (deduplication: source wins).
+    const sourceEdgesForNode = (edgesBySource.get(node.id) ?? []).filter(
+      (e) => !serializedEdges.has(e.id) && e.target !== node.parentId && e.source !== node.parentId,
+    )
+    for (const e of sourceEdgesForNode) {
+      const targetLabel = idToLabel.get(e.target)
+      if (!targetLabel) continue
+      const edgeType: EdgeType = (e.data?.type as EdgeType) ?? 'ethernet'
+      const edgeLabel = e.data?.label as string | undefined
+      if (!entry.clusterR) {
+        entry.clusterR = makeConnection(targetLabel, edgeType, edgeLabel)
+      }
+      // Only first clusterR wins per node; mark all source edges as serialized
+      serializedEdges.add(e.id)
+    }
+
+    const targetEdgesForNode = (edgesByTarget.get(node.id) ?? []).filter(
+      (e) => !serializedEdges.has(e.id) && e.source !== node.parentId && e.target !== node.parentId,
+    )
+    for (const e of targetEdgesForNode) {
+      const sourceLabel = idToLabel.get(e.source)
+      if (!sourceLabel) continue
+      const edgeType: EdgeType = (e.data?.type as EdgeType) ?? 'ethernet'
+      const edgeLabel = e.data?.label as string | undefined
+      if (!entry.clusterL) {
+        entry.clusterL = makeConnection(sourceLabel, edgeType, edgeLabel)
+      }
+      serializedEdges.add(e.id)
+    }
+
+    yamlNodes.push(entry)
+  }
+
+  return yaml.dump(yamlNodes, { lineWidth: -1, noRefs: true })
+}
+
+/** Trigger a browser file download with the given YAML content */
+export function downloadYaml(content: string, filename = 'homelable-export.yaml'): void {
+  const blob = new Blob([content], { type: 'text/yaml;charset=utf-8' })
+  const url = URL.createObjectURL(blob)
+  const a = document.createElement('a')
+  a.href = url
+  a.download = filename
+  document.body.appendChild(a)
+  a.click()
+  document.body.removeChild(a)
+  URL.revokeObjectURL(url)
+}

frontend/src/utils/importYaml.ts

@@ -0,0 +1,159 @@
+import yaml from 'js-yaml'
+import type { Node, Edge } from '@xyflow/react'
+import type { NodeData, EdgeData } from '@/types'
+import type { YamlNode, YamlNodeConnection } from '@/types/yaml'
+import { generateUUID } from '@/utils/uuid'
+import { applyDagreLayout } from '@/utils/layout'
+
+/**
+ * Parse a YAML string and merge the resulting nodes/edges into the existing canvas.
+ * - Nodes with the same label as an existing node are skipped (no duplicates).
+ * - Positions are computed via dagre auto-layout over the full merged set.
+ */
+export function parseYamlToCanvas(
+  yamlString: string,
+  existingNodes: Node<NodeData>[],
+  existingEdges: Edge<EdgeData>[],
+): { nodes: Node<NodeData>[]; edges: Edge<EdgeData>[]; imported: number } {
+  const raw = yaml.load(yamlString)
+
+  if (!Array.isArray(raw)) {
+    throw new Error('YAML must be a list of node objects (top-level array)')
+  }
+
+  const entries = raw as unknown[]
+
+  // Build lookup: label → existing node id (existing canvas + nodes being added)
+  const labelToId = new Map<string, string>()
+  for (const n of existingNodes) {
+    labelToId.set(n.data.label, n.id)
+  }
+
+  // First pass: validate and create nodes (without positions — dagre will assign them)
+  const newNodes: Node<NodeData>[] = []
+  const yamlNodes: YamlNode[] = []
+
+  for (const entry of entries) {
+    const raw = entry as Record<string, unknown>
+
+    if (!raw.nodeType || typeof raw.nodeType !== 'string') {
+      throw new Error(`Each YAML entry must have a "nodeType" string field`)
+    }
+    if (!raw.label || typeof raw.label !== 'string') {
+      throw new Error(`Each YAML entry must have a "label" string field`)
+    }
+
+    const yn = raw as unknown as YamlNode
+
+    // Skip if a node with this label already exists on the canvas
+    if (labelToId.has(yn.label)) {
+      console.warn(`[importYaml] Skipping duplicate label: "${yn.label}"`)
+      continue
+    }
+
+    const id = generateUUID()
+    labelToId.set(yn.label, id)
+
+    const hasHardware = !!(yn.cpuModel || yn.cpuCore || yn.ram || yn.disk)
+
+    const data: NodeData = {
+      label: yn.label,
+      type: yn.nodeType,
+      status: 'unknown',
+      services: [],
+      ...(yn.hostname ? { hostname: yn.hostname } : {}),
+      ...(yn.ipAddress ? { ip: yn.ipAddress } : {}),
+      ...(yn.checkMethod ? { check_method: yn.checkMethod } : {}),
+      ...(yn.checkTarget ? { check_target: yn.checkTarget } : {}),
+      ...(yn.notes ? { notes: yn.notes } : {}),
+      ...(yn.nodeIcon ? { custom_icon: yn.nodeIcon } : {}),
+      ...(yn.cpuModel ? { cpu_model: yn.cpuModel } : {}),
+      ...(yn.cpuCore ? { cpu_count: yn.cpuCore } : {}),
+      ...(yn.ram ? { ram_gb: yn.ram } : {}),
+      ...(yn.disk ? { disk_gb: yn.disk } : {}),
+      ...(hasHardware ? { show_hardware: true } : {}),
+    }
+
+    newNodes.push({
+      id,
+      type: yn.nodeType,
+      position: { x: 0, y: 0 },
+      data,
+    })
+
+    yamlNodes.push(yn)
+  }
+
+  // Second pass: apply parent relationships (parentId / parent_id)
+  const newEdges: Edge<EdgeData>[] = []
+  // Track edge pairs to deduplicate (store as "sourceId|targetId")
+  const edgePairs = new Set<string>(
+    existingEdges.map((e) => `${e.source}|${e.target}`)
+  )
+
+  function addEdgeIfNew(
+    sourceId: string,
+    targetId: string,
+    conn: YamlNodeConnection,
+  ) {
+    const key = `${sourceId}|${targetId}`
+    const reverseKey = `${targetId}|${sourceId}`
+    if (edgePairs.has(key) || edgePairs.has(reverseKey)) return
+    edgePairs.add(key)
+    const edgeType = conn.linkType ?? 'ethernet'
+    newEdges.push({
+      id: generateUUID(),
+      source: sourceId,
+      target: targetId,
+      type: edgeType,
+      data: {
+        type: edgeType,
+        ...(conn.linkLabel ? { label: conn.linkLabel } : {}),
+      },
+    })
+  }
+
+  for (let i = 0; i < newNodes.length; i++) {
+    const node = newNodes[i]
+    const yn = yamlNodes[i]
+
+    if (yn.parent) {
+      const parentId = labelToId.get(yn.parent.label)
+      if (!parentId) {
+        console.warn(`[importYaml] parent label not found: "${yn.parent.label}" — skipping relationship`)
+      } else {
+        // Set React Flow parentId for nesting
+        node.data = { ...node.data, parent_id: parentId }
+        node.parentId = parentId
+        node.extent = 'parent'
+        // Also create an edge
+        addEdgeIfNew(parentId, node.id, yn.parent)
+      }
+    }
+
+    if (yn.clusterR) {
+      const targetId = labelToId.get(yn.clusterR.label)
+      if (!targetId) {
+        console.warn(`[importYaml] clusterR label not found: "${yn.clusterR.label}" — skipping`)
+      } else {
+        addEdgeIfNew(node.id, targetId, yn.clusterR)
+      }
+    }
+
+    if (yn.clusterL) {
+      const sourceId = labelToId.get(yn.clusterL.label)
+      if (!sourceId) {
+        console.warn(`[importYaml] clusterL label not found: "${yn.clusterL.label}" — skipping`)
+      } else {
+        addEdgeIfNew(sourceId, node.id, yn.clusterL)
+      }
+    }
+  }
+
+  // Merge and apply layout
+  const mergedNodes = [...existingNodes, ...newNodes]
+  const mergedEdges = [...existingEdges, ...newEdges]
+  const laidOut = applyDagreLayout(mergedNodes, mergedEdges)
+
+  return { nodes: laidOut, edges: mergedEdges, imported: newNodes.length }
+}