diff --git a/frontend-v3-compatibility-plan.md b/frontend-v3-compatibility-plan.md
new file mode 100644
index 000000000..ebb5305ce
--- /dev/null
+++ b/frontend-v3-compatibility-plan.md
@@ -0,0 +1,502 @@
+# Frontend V3 Compatibility Layer Implementation Plan (Import-Based API Versioning)
+
+## Overview
+
+This document outlines an **import-based API versioning** approach for implementing v3 compatibility in the ComfyUI frontend. This approach provides **type-safe API versioning** through import-based version selection, **dual endpoint data fetching**, and **proxy-based data synchronization**. Extensions choose their API version at import time, ensuring compile-time type safety and backward compatibility.
+
+## Key Design Principles
+
+1. **Import-Based Version Selection**: Extensions choose API version through import statements
+2. **Type-Safe API Surfaces**: Compile-time type checking for each API version
+3. **Dual Endpoint Fetching**: Simultaneous fetching from current and v3 endpoints
+4. **Proxy-Based Synchronization**: Bidirectional data sync between API versions
+5. **Zero Breaking Changes**: Existing extensions continue to work unchanged
+6. **Gradual Migration**: Developers can adopt new versions incrementally
+
+## Architecture Overview
+
+### 1. Import-Based API Version Selection
+
+Extensions import the API version they want to use, getting typed interfaces and guaranteed compatibility:
+
+```typescript
+// Legacy extensions (unchanged)
+import { app } from '@/scripts/app'
+
+// Version-specific imports
+import { app } from '@/scripts/app/v1'           // v1.x API
+import { app } from '@/scripts/app/v1_2'         // v1.2 API  
+import { app } from '@/scripts/app/v2'           // v2.x API
+import { app } from '@/scripts/app/latest'       // Latest/bleeding edge
+import { app } from '@/scripts/app'              // Defaults to latest
+
+// Full version-specific imports
+import { app, extensionManager, api } from '@/scripts/app/v1_2'
+
+// Extensions get typed, version-specific interfaces
+app.registerExtension({
+  name: 'MyExtension',
+  beforeRegisterNodeDef(nodeType, nodeData: ComfyNodeDefV1_2, app: ComfyAppV1_2) {
+    // nodeData is guaranteed to be in v1.2 format
+    // app methods are v1.2 compatible
+  }
+})
+```
+
+### 2. Dual Endpoint Data Fetching
+
+The system fetches data from both current and future API endpoints simultaneously:
+
+```typescript
+// Fetch from multiple endpoints
+const fetchNodeDefinitions = async () => {
+  const [currentResponse, v3Response] = await Promise.allSettled([
+    api.get('/object_info'),      // Current format
+    api.get('/v3/object_info')    // V3 format (when available)
+  ])
+  
+  // Store all formats
+  return {
+    canonical: mergeToCanonical(currentResponse, v3Response),
+    v1: transformToV1(currentResponse),
+    v1_2: transformToV1_2(currentResponse),
+    v3: v3Response || transformToV3(currentResponse)
+  }
+}
+```
+
+### 3. Proxy-Based Data Synchronization
+
+Proxies ensure that changes made through any API version stay synchronized:
+
+```typescript
+// Extension modifies node data through v1.2 API
+const createV1_2NodeDefProxy = (canonicalNodeDef: ComfyNodeDefLatest) => {
+  return new Proxy({}, {
+    get(target, prop) {
+      // Map v1.2 property access to canonical format
+      if (prop === 'input') {
+        return transformLatestToV1_2Input(canonicalNodeDef.inputs)
+      }
+      return canonicalNodeDef[mapV1_2PropToLatest(prop)]
+    },
+    
+    set(target, prop, value) {
+      // Map v1.2 property changes back to canonical format  
+      if (prop === 'input') {
+        canonicalNodeDef.inputs = transformV1_2InputToLatest(value)
+        notifyDataChange(canonicalNodeDef.name, prop, value)
+        return true
+      }
+      canonicalNodeDef[mapV1_2PropToLatest(prop)] = value
+      return true
+    }
+  })
+}
+```
+
+## Implementation Architecture
+
+### Phase 1: API Version Infrastructure
+
+**1.1 Version-Specific Entry Points**
+```typescript
+// src/scripts/app/index.ts (latest/default)
+export * from './latest'
+
+// src/scripts/app/v1.ts  
+export { app as default } from './adapters/v1AppAdapter'
+export { extensionManager } from './adapters/v1ExtensionAdapter'
+export { api } from './adapters/v1ApiAdapter'
+
+// src/scripts/app/v1_2.ts
+export { app as default } from './adapters/v1_2AppAdapter' 
+export { extensionManager } from './adapters/v1_2ExtensionAdapter'
+export { api } from './adapters/v1_2ApiAdapter'
+```
+
+**1.2 Version-Specific TypeScript Interfaces**
+```typescript
+// src/types/versions/v1.ts
+export interface ComfyNodeDefV1 {
+  name: string
+  input?: {
+    required?: Record<string, any>
+    optional?: Record<string, any>
+  }
+  output?: string[]
+  output_is_list?: boolean[]
+}
+
+// src/types/versions/v1_2.ts  
+export interface ComfyNodeDefV1_2 extends ComfyNodeDefV1 {
+  inputs?: ComfyInputSpecV1_2[]
+  metadata?: NodeMetadataV1_2
+}
+
+// src/types/versions/v3.ts
+export interface ComfyNodeDefV3 {
+  name: string
+  schema: JsonSchema
+  inputs: InputSpecV3[]
+  outputs: OutputSpecV3[]
+}
+```
+
+### Phase 2: Multi-Version Data Layer
+
+**2.1 Unified Data Store**
+```typescript
+// src/stores/nodeDefStore.ts
+export const useNodeDefStore = defineStore('nodeDef', () => {
+  const nodeDefinitions = ref<{
+    canonical: Record<string, ComfyNodeDefLatest>
+    v1: Record<string, ComfyNodeDefV1>
+    v1_2: Record<string, ComfyNodeDefV1_2>
+    v3: Record<string, ComfyNodeDefV3>
+  }>({
+    canonical: {},
+    v1: {},
+    v1_2: {},
+    v3: {}
+  })
+  
+  const fetchNodeDefinitions = async () => {
+    const [currentData, v3Data] = await Promise.allSettled([
+      api.get('/object_info'),
+      api.get('/v3/object_info')
+    ])
+    
+    nodeDefinitions.value = transformToAllVersions(currentData, v3Data)
+  }
+  
+  // Version-specific getters with reactivity
+  const getNodeDefsV1 = computed(() => nodeDefinitions.value.v1)
+  const getNodeDefsV1_2 = computed(() => nodeDefinitions.value.v1_2)
+  const getNodeDefsV3 = computed(() => nodeDefinitions.value.v3)
+  
+  return {
+    nodeDefinitions,
+    fetchNodeDefinitions,
+    getNodeDefsV1,
+    getNodeDefsV1_2, 
+    getNodeDefsV3
+  }
+})
+```
+
+**2.2 Data Transformation Pipeline**
+```typescript
+// src/utils/versionTransforms.ts
+export class VersionTransforms {
+  static transformToAllVersions(currentData: any, v3Data: any) {
+    const canonical = this.createCanonicalFormat(currentData, v3Data)
+    
+    return {
+      canonical,
+      v1: this.canonicalToV1(canonical),
+      v1_2: this.canonicalToV1_2(canonical),
+      v3: v3Data || this.canonicalToV3(canonical)
+    }
+  }
+  
+  static canonicalToV1(canonical: ComfyNodeDefLatest): ComfyNodeDefV1 {
+    return {
+      name: canonical.name,
+      input: {
+        required: canonical.inputs
+          ?.filter(i => i.required)
+          .reduce((acc, input) => {
+            acc[input.name] = input.spec
+            return acc
+          }, {} as Record<string, any>),
+        optional: canonical.inputs
+          ?.filter(i => !i.required)
+          .reduce((acc, input) => {
+            acc[input.name] = input.spec
+            return acc
+          }, {} as Record<string, any>)
+      },
+      output: canonical.outputs?.map(o => o.type),
+      output_is_list: canonical.outputs?.map(o => o.is_list)
+    }
+  }
+  
+  static canonicalToV1_2(canonical: ComfyNodeDefLatest): ComfyNodeDefV1_2 {
+    return {
+      ...this.canonicalToV1(canonical),
+      inputs: canonical.inputs?.map(input => ({
+        name: input.name,
+        type: input.type,
+        required: input.required,
+        options: input.options
+      }))
+    }
+  }
+}
+```
+
+### Phase 3: Proxy-Based Synchronization
+
+**3.1 Bidirectional Data Proxies**
+```typescript
+// src/utils/versionProxies.ts
+export class VersionProxies {
+  private static canonicalStore = new Map<string, ComfyNodeDefLatest>()
+  private static eventBus = new EventTarget()
+  
+  static createV1Proxy(nodeId: string): ComfyNodeDefV1 {
+    const canonical = this.canonicalStore.get(nodeId)
+    if (!canonical) throw new Error(`Node ${nodeId} not found`)
+    
+    return new Proxy({} as ComfyNodeDefV1, {
+      get(target, prop: keyof ComfyNodeDefV1) {
+        return VersionProxies.transformCanonicalToV1Property(canonical, prop)
+      },
+      
+      set(target, prop: keyof ComfyNodeDefV1, value) {
+        VersionProxies.transformV1PropertyToCanonical(canonical, prop, value)
+        VersionProxies.notifyChange(nodeId, prop, value)
+        return true
+      }
+    })
+  }
+  
+  static createV1_2Proxy(nodeId: string): ComfyNodeDefV1_2 {
+    const canonical = this.canonicalStore.get(nodeId)
+    if (!canonical) throw new Error(`Node ${nodeId} not found`)
+    
+    return new Proxy({} as ComfyNodeDefV1_2, {
+      get(target, prop: keyof ComfyNodeDefV1_2) {
+        return VersionProxies.transformCanonicalToV1_2Property(canonical, prop)
+      },
+      
+      set(target, prop: keyof ComfyNodeDefV1_2, value) {
+        VersionProxies.transformV1_2PropertyToCanonical(canonical, prop, value)
+        VersionProxies.notifyChange(nodeId, prop, value)
+        return true
+      }
+    })
+  }
+  
+  private static transformCanonicalToV1Property(canonical: ComfyNodeDefLatest, prop: keyof ComfyNodeDefV1) {
+    switch (prop) {
+      case 'input':
+        return {
+          required: canonical.inputs?.filter(i => i.required).reduce((acc, input) => {
+            acc[input.name] = input.spec
+            return acc
+          }, {} as Record<string, any>),
+          optional: canonical.inputs?.filter(i => !i.required).reduce((acc, input) => {
+            acc[input.name] = input.spec
+            return acc
+          }, {} as Record<string, any>)
+        }
+      case 'output':
+        return canonical.outputs?.map(o => o.type)
+      case 'output_is_list':
+        return canonical.outputs?.map(o => o.is_list)
+      default:
+        return canonical[prop as keyof ComfyNodeDefLatest]
+    }
+  }
+  
+  private static transformV1PropertyToCanonical(canonical: ComfyNodeDefLatest, prop: keyof ComfyNodeDefV1, value: any) {
+    switch (prop) {
+      case 'input':
+        canonical.inputs = [
+          ...Object.entries(value.required || {}).map(([name, spec]) => ({
+            name,
+            spec,
+            required: true,
+            type: this.inferTypeFromSpec(spec)
+          })),
+          ...Object.entries(value.optional || {}).map(([name, spec]) => ({
+            name,
+            spec,
+            required: false,
+            type: this.inferTypeFromSpec(spec)
+          }))
+        ]
+        break
+      case 'output':
+        canonical.outputs = value.map((type: string, index: number) => ({
+          type,
+          is_list: canonical.outputs?.[index]?.is_list || false
+        }))
+        break
+      case 'output_is_list':
+        canonical.outputs = canonical.outputs?.map((output, index) => ({
+          ...output,
+          is_list: value[index] || false
+        }))
+        break
+      default:
+        (canonical as any)[prop] = value
+    }
+  }
+  
+  private static notifyChange(nodeId: string, prop: string, value: any) {
+    this.eventBus.dispatchEvent(new CustomEvent('nodedef-changed', {
+      detail: { nodeId, prop, value }
+    }))
+  }
+}
+```
+
+### Phase 4: Extension System Integration
+
+**4.1 Version-Aware Extension Service**
+```typescript
+// src/services/extensionService.ts
+export const useExtensionService = () => {
+  const extensionsByVersion = new Map<string, ComfyExtension[]>()
+  
+  const registerExtension = (extension: ComfyExtension, apiVersion: string = 'latest') => {
+    extension.apiVersion = apiVersion
+    
+    if (!extensionsByVersion.has(apiVersion)) {
+      extensionsByVersion.set(apiVersion, [])
+    }
+    extensionsByVersion.get(apiVersion)!.push(extension)
+  }
+  
+  const invokeExtensionsForAllVersions = async (hook: string, canonicalArgs: any[]) => {
+    const promises = []
+    
+    for (const [version, extensions] of extensionsByVersion) {
+      const versionPromise = invokeExtensionsForVersion(version, hook, canonicalArgs)
+      promises.push(versionPromise)
+    }
+    
+    await Promise.all(promises)
+  }
+  
+  const invokeExtensionsForVersion = async (version: string, hook: string, canonicalArgs: any[]) => {
+    const extensions = extensionsByVersion.get(version) || []
+    
+    for (const extension of extensions) {
+      if (extension[hook]) {
+        const transformedArgs = transformArgsForVersion(version, canonicalArgs)
+        await extension[hook](...transformedArgs)
+      }
+    }
+  }
+  
+  const transformArgsForVersion = (version: string, args: any[]) => {
+    return args.map(arg => {
+      if (arg && typeof arg === 'object' && arg.name) {
+        // This is likely a node definition
+        switch (version) {
+          case 'v1':
+            return VersionProxies.createV1Proxy(arg.name)
+          case 'v1_2':
+            return VersionProxies.createV1_2Proxy(arg.name)
+          case 'v3':
+            return VersionProxies.createV3Proxy(arg.name)
+          default:
+            return arg
+        }
+      }
+      return arg
+    })
+  }
+  
+  return {
+    registerExtension,
+    invokeExtensionsForAllVersions,
+    invokeExtensionsForVersion
+  }
+}
+```
+
+**4.2 Version-Specific App Adapters**
+```typescript
+// src/scripts/app/adapters/v1AppAdapter.ts
+export class V1AppAdapter {
+  constructor(private canonicalApp: ComfyApp) {}
+  
+  registerExtension(extension: ComfyExtensionV1) {
+    const wrappedExtension = {
+      ...extension,
+      apiVersion: 'v1',
+      beforeRegisterNodeDef: (nodeType, nodeData, app) => {
+        const v1NodeData = VersionProxies.createV1Proxy(nodeData.name)
+        return extension.beforeRegisterNodeDef?.(nodeType, v1NodeData, this)
+      },
+      nodeCreated: (node, app) => {
+        return extension.nodeCreated?.(node, this)
+      }
+    }
+    
+    this.canonicalApp.registerExtension(wrappedExtension)
+  }
+  
+  // Implement other ComfyApp methods with v1 compatibility
+}
+
+// src/scripts/app/adapters/v1_2AppAdapter.ts
+export class V1_2AppAdapter {
+  constructor(private canonicalApp: ComfyApp) {}
+  
+  registerExtension(extension: ComfyExtensionV1_2) {
+    const wrappedExtension = {
+      ...extension,
+      apiVersion: 'v1_2',
+      beforeRegisterNodeDef: (nodeType, nodeData, app) => {
+        const v1_2NodeData = VersionProxies.createV1_2Proxy(nodeData.name)
+        return extension.beforeRegisterNodeDef?.(nodeType, v1_2NodeData, this)
+      }
+    }
+    
+    this.canonicalApp.registerExtension(wrappedExtension)
+  }
+}
+```
+
+## Migration Strategy
+
+### Gradual Migration Path
+
+Extensions can migrate incrementally:
+
+```typescript
+// Phase 1: No changes (works with latest)
+import { app } from '@/scripts/app'
+
+// Phase 2: Explicit version (better compatibility)
+import { app } from '@/scripts/app/v1_2'
+
+// Phase 3: Use newer APIs when ready
+import { app } from '@/scripts/app/latest'
+```
+
+### Development Tools
+
+```typescript
+// Enhanced debugging for version compatibility
+ComfyUI.debugExtensions.showVersionMatrix() // Shows which extensions use which API versions
+ComfyUI.debugExtensions.testVersionCompatibility() // Tests extension against all API versions
+ComfyUI.debugExtensions.validateDataSync() // Validates proxy synchronization
+```
+
+## Benefits
+
+1. **Type Safety**: Compile-time type checking for each API version
+2. **Zero Breaking Changes**: Existing extensions work unchanged
+3. **Bidirectional Sync**: Changes through any API version stay synchronized
+4. **Future Proof**: Easy to add new API versions
+5. **Performance**: No runtime version detection overhead
+6. **Developer Experience**: Clear, typed interfaces for each version
+
+## Implementation Timeline
+
+- **Phase 1**: API Version Infrastructure (3-4 days)
+- **Phase 2**: Multi-Version Data Layer (2-3 days)
+- **Phase 3**: Proxy-Based Synchronization (2-3 days)
+- **Phase 4**: Extension System Integration (2-3 days)
+- **Phase 5**: Migration Tools & Documentation (1-2 days)
+
+**Total Estimated Time**: 10-15 days
+
+This approach provides a solid foundation for API versioning that scales with ComfyUI's growth while maintaining backward compatibility and providing a smooth migration path for extension developers.
\ No newline at end of file
diff --git a/frontend-v3-compatibility-summary.md b/frontend-v3-compatibility-summary.md
new file mode 100644
index 000000000..6ce69dcc2
--- /dev/null
+++ b/frontend-v3-compatibility-summary.md
@@ -0,0 +1,134 @@
+# ComfyUI Frontend V3 Compatibility - Implementation Summary
+
+## Core Concept
+**Import-based API versioning** with proxy-synchronized data layers. Extensions choose their API version through imports, getting typed interfaces and guaranteed backward compatibility.
+
+## Architecture Overview
+
+### 1. Version-Specific Imports
+```typescript
+// Legacy (unchanged)
+import { app } from '@/scripts/app'
+
+// Version-specific
+import { app } from '@/scripts/app/v1'       // v1.x API
+import { app } from '@/scripts/app/v1_2'     // v1.2 API
+import { app } from '@/scripts/app/v3'       // v3.x API
+import { app } from '@/scripts/app/latest'   // Latest
+
+// Typed interfaces per version
+app.registerExtension({
+  beforeRegisterNodeDef(nodeType, nodeData: ComfyNodeDefV1_2, app: ComfyAppV1_2) {
+    // nodeData guaranteed to be v1.2 format
+  }
+})
+```
+
+### 2. Dual Endpoint Data Fetching
+```typescript
+// Simultaneous fetching from multiple endpoints
+const [currentData, v3Data] = await Promise.allSettled([
+  api.get('/object_info'),      // Current format
+  api.get('/v3/object_info')    // V3 format
+])
+
+// All versions stored and transformed
+nodeDefinitions.value = {
+  canonical: mergeToCanonical(currentData, v3Data),
+  v1: transformToV1(currentData),
+  v1_2: transformToV1_2(currentData),
+  v3: v3Data || transformToV3(currentData)
+}
+```
+
+### 3. Proxy-Based Synchronization
+```typescript
+// Bidirectional data sync through proxies
+const createV1_2Proxy = (canonical: ComfyNodeDefLatest) => {
+  return new Proxy({}, {
+    get(target, prop) {
+      return transformCanonicalToV1_2(canonical, prop)
+    },
+    set(target, prop, value) {
+      transformV1_2ToCanonical(canonical, prop, value)
+      notifyChange(canonical.name, prop, value)
+      return true
+    }
+  })
+}
+```
+
+## Implementation Structure
+
+### Phase 1: API Infrastructure (3-4 days)
+- **Entry Points**: `src/scripts/app/v1.ts`, `src/scripts/app/v1_2.ts`, etc.
+- **Type Definitions**: `src/types/versions/` with version-specific interfaces
+- **Adapters**: `src/scripts/app/adapters/` for API compatibility layers
+
+### Phase 2: Data Layer (2-3 days)
+- **Multi-Version Store**: Single store with all format versions
+- **Transform Pipeline**: `src/utils/versionTransforms.ts` for format conversion
+- **Reactive Getters**: Version-specific computed properties
+
+### Phase 3: Proxy System (2-3 days)
+- **Bidirectional Proxies**: `src/utils/versionProxies.ts`
+- **Change Notification**: Event system for data sync
+- **Type Safety**: Proper typing for proxy objects
+
+### Phase 4: Extension Integration (2-3 days)
+- **Version-Aware Service**: Extensions grouped by API version
+- **Hook Invocation**: Transform args per version before calling
+- **App Adapters**: Version-specific app instances
+
+## Key Benefits
+
+- **Type Safety**: Compile-time checking for each API version
+- **Zero Breaking Changes**: Existing extensions work unchanged
+- **Bidirectional Sync**: Changes through any API stay synchronized
+- **Performance**: No runtime version detection overhead
+- **Future Proof**: Easy to add new API versions
+- **Developer Experience**: Clear, typed interfaces
+
+## Migration Path
+
+```typescript
+// Step 1: No changes (works with latest)
+import { app } from '@/scripts/app'
+
+// Step 2: Explicit version (better compatibility)  
+import { app } from '@/scripts/app/v1_2'
+
+// Step 3: Use newer APIs when ready
+import { app } from '@/scripts/app/latest'
+```
+
+## Example Usage
+
+```typescript
+// v1.2 Extension
+import { app } from '@/scripts/app/v1_2'
+
+app.registerExtension({
+  name: 'MyExtension',
+  beforeRegisterNodeDef(nodeType, nodeData: ComfyNodeDefV1_2, app) {
+    // nodeData.input.required - v1 format
+    // nodeData.inputs - v1.2 format
+    if (nodeData.inputs) {
+      // Use v1.2 features
+    } else {
+      // Fallback to v1 format
+    }
+  }
+})
+```
+
+## Implementation Timeline
+- **Phase 1**: API Version Infrastructure (3-4 days)
+- **Phase 2**: Multi-Version Data Layer (2-3 days)  
+- **Phase 3**: Proxy-Based Synchronization (2-3 days)
+- **Phase 4**: Extension System Integration (2-3 days)
+- **Phase 5**: Migration Tools & Documentation (1-2 days)
+
+**Total**: 10-15 days
+
+This approach provides type-safe API versioning that scales with ComfyUI's growth while maintaining complete backward compatibility and smooth migration paths for extension developers.
\ No newline at end of file
diff --git a/src/services/extensionService.ts b/src/services/extensionService.ts
index 1fd92b256..3aa4712ed 100644
--- a/src/services/extensionService.ts
+++ b/src/services/extensionService.ts
@@ -9,6 +9,7 @@ import { useSettingStore } from '@/stores/settingStore'
 import { useWidgetStore } from '@/stores/widgetStore'
 import { useBottomPanelStore } from '@/stores/workspace/bottomPanelStore'
 import type { ComfyExtension } from '@/types/comfy'
+import { VersionProxies } from '@/utils/versionProxies'
 
 export const useExtensionService = () => {
   const extensionStore = useExtensionStore()
@@ -128,10 +129,132 @@ export const useExtensionService = () => {
     )
   }
 
+  /**
+   * Register extension with API version tracking
+   */
+  const registerExtensionWithVersion = (
+    extension: ComfyExtension,
+    apiVersion: string = 'latest'
+  ) => {
+    extension.apiVersion = apiVersion
+    registerExtension(extension)
+  }
+
+  /**
+   * Invoke extensions for a specific API version with transformed args
+   */
+  const invokeExtensionsForVersion = async <T extends any[]>(
+    hook: keyof ComfyExtension,
+    apiVersion: string,
+    ...args: T
+  ) => {
+    const extensions = extensionStore.extensions.filter(
+      (ext) =>
+        ext.apiVersion === apiVersion ||
+        (!ext.apiVersion && apiVersion === 'latest')
+    )
+
+    for (const extension of extensions) {
+      if (extension[hook] && typeof extension[hook] === 'function') {
+        try {
+          const transformedArgs = transformArgsForVersion(apiVersion, args)
+          await (extension[hook] as (...args: T) => void | Promise<void>)(
+            ...transformedArgs
+          )
+        } catch (error) {
+          console.error(
+            `Error in extension ${extension.name} hook ${String(hook)}:`,
+            error
+          )
+        }
+      }
+    }
+  }
+
+  /**
+   * Invoke extensions for all API versions with appropriate data transformation
+   */
+  const invokeExtensionsForAllVersions = async <T extends any[]>(
+    hook: keyof ComfyExtension,
+    ...args: T
+  ) => {
+    const apiVersions = new Set(['latest', 'v1', 'v1_2', 'v3'])
+    const promises = []
+
+    for (const version of apiVersions) {
+      promises.push(invokeExtensionsForVersion(hook, version, ...args))
+    }
+
+    await Promise.all(promises)
+  }
+
+  /**
+   * Transform arguments for specific API version
+   */
+  const transformArgsForVersion = (version: string, args: any[]) => {
+    return args.map((arg) => {
+      // If argument looks like a node definition, create appropriate proxy
+      if (
+        arg &&
+        typeof arg === 'object' &&
+        arg.name &&
+        typeof arg.name === 'string'
+      ) {
+        try {
+          switch (version) {
+            case 'v1':
+              return VersionProxies.createV1Proxy(arg.name)
+            case 'v1_2':
+              return VersionProxies.createV1_2Proxy(arg.name)
+            case 'v3':
+              return VersionProxies.createV3Proxy(arg.name)
+            default:
+              return arg
+          }
+        } catch (error) {
+          // If proxy creation fails, return original arg
+          console.warn(`Failed to create proxy for node ${arg.name}:`, error)
+          return arg
+        }
+      }
+      return arg
+    })
+  }
+
+  /**
+   * Get extension compatibility report by API version
+   */
+  const getExtensionVersionReport = () => {
+    const extensions = extensionStore.extensions
+    const versionGroups = extensions.reduce(
+      (acc, ext) => {
+        const version = ext.apiVersion || 'latest'
+        if (!acc[version]) acc[version] = []
+        acc[version].push(ext)
+        return acc
+      },
+      {} as Record<string, ComfyExtension[]>
+    )
+
+    return {
+      total: extensions.length,
+      versionGroups,
+      details: Object.entries(versionGroups).map(([version, exts]) => ({
+        version,
+        count: exts.length,
+        extensions: exts.map((ext) => ext.name)
+      }))
+    }
+  }
+
   return {
     loadExtensions,
     registerExtension,
+    registerExtensionWithVersion,
     invokeExtensions,
-    invokeExtensionsAsync
+    invokeExtensionsAsync,
+    invokeExtensionsForVersion,
+    invokeExtensionsForAllVersions,
+    getExtensionVersionReport
   }
 }
diff --git a/src/types/comfy.ts b/src/types/comfy.ts
index f78fccaeb..3a8de84c0 100644
--- a/src/types/comfy.ts
+++ b/src/types/comfy.ts
@@ -47,6 +47,10 @@ export interface ComfyExtension {
    * The name of the extension
    */
   name: string
+  /**
+   * API version this extension is using (set automatically by import)
+   */
+  apiVersion?: string
   /**
    * The commands defined by the extension
    */
diff --git a/src/types/versions/index.ts b/src/types/versions/index.ts
new file mode 100644
index 000000000..ca18c0ca6
--- /dev/null
+++ b/src/types/versions/index.ts
@@ -0,0 +1,4 @@
+// Re-export all version-specific types
+export * from './v1'
+export * from './v1_2'
+export * from './v3'
diff --git a/src/types/versions/v1.ts b/src/types/versions/v1.ts
new file mode 100644
index 000000000..74cd237bb
--- /dev/null
+++ b/src/types/versions/v1.ts
@@ -0,0 +1,101 @@
+import type { LGraphNode } from '@comfyorg/litegraph'
+
+/**
+ * V1 API node definition interface
+ * This represents the current/legacy node definition format
+ */
+export interface ComfyNodeDefV1 {
+  name: string
+  display_name?: string
+  description?: string
+  category?: string
+  output_node?: boolean
+  input?: {
+    required?: Record<string, any>
+    optional?: Record<string, any>
+    hidden?: Record<string, any>
+  }
+  output?: string[]
+  output_is_list?: boolean[]
+  output_name?: string[]
+  output_tooltips?: string[]
+  python_module?: string
+  deprecated?: boolean
+  experimental?: boolean
+}
+
+/**
+ * V1 API extension interface
+ */
+export interface ComfyExtensionV1 {
+  name: string
+  apiVersion?: 'v1'
+
+  // Lifecycle hooks
+  init?(): void | Promise<void>
+  setup?(): void | Promise<void>
+
+  // Node lifecycle hooks
+  beforeRegisterNodeDef?(
+    nodeType: typeof LGraphNode,
+    nodeData: ComfyNodeDefV1,
+    app: ComfyAppV1
+  ): void
+  nodeCreated?(node: LGraphNode, app: ComfyAppV1): void
+
+  // Graph hooks
+  beforeConfigureGraph?(graphData: any, missingNodeTypes: any[]): void
+  afterConfigureGraph?(missingNodeTypes: any[]): void
+
+  // Canvas hooks
+  getCustomWidgets?(): Record<string, any>
+
+  // Menu hooks
+  addCustomNodeDefs?(defs: ComfyNodeDefV1[]): ComfyNodeDefV1[]
+
+  // Settings
+  settings?: Array<{
+    id: string
+    name: string
+    type: string
+    defaultValue: any
+    tooltip?: string
+  }>
+
+  // Commands
+  commands?: Array<{
+    id: string
+    function: () => void | Promise<void>
+  }>
+
+  // Keybindings
+  keybindings?: Array<{
+    combo: { key: string; ctrl?: boolean; shift?: boolean; alt?: boolean }
+    commandId: string
+  }>
+}
+
+/**
+ * V1 API ComfyApp interface
+ * Provides the same interface as the current app
+ */
+export interface ComfyAppV1 {
+  registerExtension(extension: ComfyExtensionV1): void
+
+  // Graph management
+  loadGraphData(graphData: any): Promise<void>
+  clean(): void
+
+  // Node management
+  getNodeById(id: number): LGraphNode | null
+
+  // Workflow operations
+  queuePrompt(number: number, batchCount?: number): Promise<void>
+
+  // Canvas operations
+  canvas: any
+  graph: any
+
+  // UI state
+  ui: any
+}
diff --git a/src/types/versions/v1_2.ts b/src/types/versions/v1_2.ts
new file mode 100644
index 000000000..e7972e243
--- /dev/null
+++ b/src/types/versions/v1_2.ts
@@ -0,0 +1,111 @@
+import type { ComfyAppV1, ComfyExtensionV1, ComfyNodeDefV1 } from './v1'
+
+/**
+ * V1.2 API node definition interface
+ * Extends V1 with additional structured input information
+ */
+export interface ComfyNodeDefV1_2 extends ComfyNodeDefV1 {
+  inputs?: Array<{
+    name: string
+    type: string
+    required: boolean
+    options?: any
+    spec?: any
+    tooltip?: string
+    default?: any
+  }>
+
+  metadata?: {
+    version?: string
+    author?: string
+    description?: string
+    tags?: string[]
+    documentation?: string
+  }
+
+  // Enhanced output information
+  outputs?: Array<{
+    name: string
+    type: string
+    is_list: boolean
+    tooltip?: string
+  }>
+}
+
+/**
+ * V1.2 API extension interface
+ * Extends V1 with additional capabilities
+ */
+export interface ComfyExtensionV1_2 extends ComfyExtensionV1 {
+  apiVersion?: 'v1_2'
+
+  // V1.2 specific hooks
+  beforeRegisterNodeDef?(
+    nodeType: any,
+    nodeData: ComfyNodeDefV1_2,
+    app: ComfyAppV1_2
+  ): void
+  nodeCreated?(node: any, app: ComfyAppV1_2): void
+
+  // Enhanced settings with validation
+  settings?: Array<{
+    id: string
+    name: string
+    type: string
+    defaultValue: any
+    tooltip?: string
+    validation?: (value: any) => boolean | string
+    category?: string
+    options?: any[]
+  }>
+
+  // Enhanced commands with descriptions
+  commands?: Array<{
+    id: string
+    function: () => void | Promise<void>
+    label?: string
+    tooltip?: string
+    category?: string
+    icon?: string
+  }>
+
+  // Bottom panel tabs
+  bottomPanelTabs?: Array<{
+    id: string
+    title: string
+    icon: string
+    type: 'vue' | 'custom'
+    component?: any
+    tooltip?: string
+  }>
+
+  // Menu items
+  menuItems?: Array<{
+    path: string[]
+    commands: string[]
+  }>
+}
+
+/**
+ * V1.2 API ComfyApp interface
+ * Extends V1 with additional functionality
+ */
+export interface ComfyAppV1_2 extends ComfyAppV1 {
+  registerExtension(extension: ComfyExtensionV1_2): void
+
+  // Enhanced node operations
+  createNode(type: string, title?: string, options?: any): any
+  removeNode(node: any): void
+
+  // Settings operations
+  getSetting(id: string): any
+  setSetting(id: string, value: any): void
+
+  // Command operations
+  executeCommand(id: string): Promise<void>
+
+  // Enhanced UI access
+  bottomPanel: any
+  sidebar: any
+  menu: any
+}
diff --git a/src/types/versions/v3.ts b/src/types/versions/v3.ts
new file mode 100644
index 000000000..cd5b9e101
--- /dev/null
+++ b/src/types/versions/v3.ts
@@ -0,0 +1,288 @@
+/**
+ * V3 API node definition interface
+ * Future schema-based node definition format
+ */
+export interface ComfyNodeDefV3 {
+  name: string
+  display_name?: string
+  description?: string
+  category?: string
+  output_node?: boolean
+
+  // JSON Schema-based definition
+  schema: {
+    type: 'object'
+    properties: Record<string, any>
+    required?: string[]
+    additionalProperties?: boolean
+  }
+
+  // Structured input/output definitions
+  inputs: Array<{
+    name: string
+    type: string
+    required: boolean
+    schema: any
+    validation?: any
+    tooltip?: string
+    default?: any
+    ui?: {
+      widget?: string
+      options?: any
+    }
+  }>
+
+  outputs: Array<{
+    name: string
+    type: string
+    is_list: boolean
+    schema?: any
+    tooltip?: string
+  }>
+
+  // Enhanced metadata
+  metadata: {
+    version: string
+    author: string
+    description: string
+    tags: string[]
+    documentation?: string
+    repository?: string
+    license?: string
+    dependencies?: Array<{
+      name: string
+      version?: string
+      optional?: boolean
+    }>
+  }
+
+  // Execution information
+  execution?: {
+    async?: boolean
+    gpu_memory?: number
+    cpu_cores?: number
+    timeout?: number
+    retries?: number
+  }
+
+  python_module?: string
+  deprecated?: boolean
+  experimental?: boolean
+}
+
+/**
+ * V3 API extension interface
+ * Future extension format with enhanced capabilities
+ */
+export interface ComfyExtensionV3 {
+  name: string
+  apiVersion: 'v3'
+
+  // Required metadata
+  metadata: {
+    version: string
+    author: string
+    description: string
+    repository?: string
+    license?: string
+    dependencies?: Array<{
+      name: string
+      version?: string
+      optional?: boolean
+    }>
+  }
+
+  // Lifecycle hooks with enhanced data
+  init?(): void | Promise<void>
+  setup?(): void | Promise<void>
+  beforeShutdown?(): void | Promise<void>
+
+  // Node lifecycle hooks
+  beforeRegisterNodeDef?(
+    nodeType: any,
+    nodeData: ComfyNodeDefV3,
+    app: ComfyAppV3
+  ): void | Promise<void>
+  afterRegisterNodeDef?(
+    nodeType: any,
+    nodeData: ComfyNodeDefV3,
+    app: ComfyAppV3
+  ): void | Promise<void>
+  nodeCreated?(node: any, app: ComfyAppV3): void | Promise<void>
+  nodeRemoved?(node: any, app: ComfyAppV3): void | Promise<void>
+
+  // Graph hooks
+  beforeConfigureGraph?(
+    graphData: any,
+    missingNodeTypes: any[]
+  ): void | Promise<void>
+  afterConfigureGraph?(missingNodeTypes: any[]): void | Promise<void>
+  graphChanged?(graph: any): void | Promise<void>
+
+  // Enhanced settings with full schema validation
+  settings?: Array<{
+    id: string
+    name: string
+    schema: any
+    defaultValue: any
+    tooltip?: string
+    category?: string
+    validation?: (value: any) => boolean | string
+    ui?: {
+      widget?: string
+      options?: any
+    }
+  }>
+
+  // Enhanced commands with full metadata
+  commands?: Array<{
+    id: string
+    function: () => void | Promise<void>
+    metadata: {
+      label: string
+      tooltip?: string
+      category?: string
+      icon?: string
+      shortcut?: string
+    }
+    validation?: () => boolean
+  }>
+
+  // Keybindings with enhanced options
+  keybindings?: Array<{
+    combo: {
+      key: string
+      ctrl?: boolean
+      shift?: boolean
+      alt?: boolean
+      meta?: boolean
+    }
+    commandId: string
+    when?: string // Context condition
+    priority?: number
+  }>
+
+  // UI extensions
+  uiExtensions?: {
+    bottomPanelTabs?: Array<{
+      id: string
+      title: string
+      icon: string
+      component: any
+      tooltip?: string
+      when?: string
+    }>
+
+    contextMenus?: Array<{
+      id: string
+      items: Array<{
+        id: string
+        label: string
+        commandId: string
+        when?: string
+        separator?: boolean
+      }>
+    }>
+
+    toolbars?: Array<{
+      id: string
+      location: 'top' | 'bottom' | 'left' | 'right'
+      items: Array<{
+        id: string
+        type: 'button' | 'separator' | 'dropdown'
+        commandId?: string
+        label?: string
+        icon?: string
+        tooltip?: string
+      }>
+    }>
+  }
+
+  // API endpoints (for extensions that provide their own APIs)
+  apiEndpoints?: Array<{
+    path: string
+    method: 'GET' | 'POST' | 'PUT' | 'DELETE' | 'PATCH'
+    handler: (req: any, res: any) => void | Promise<void>
+    schema?: any
+    auth?: boolean
+  }>
+}
+
+/**
+ * V3 API ComfyApp interface
+ * Future app interface with enhanced capabilities
+ */
+export interface ComfyAppV3 {
+  registerExtension(extension: ComfyExtensionV3): Promise<void>
+
+  // Enhanced graph management
+  graph: {
+    load(data: any): Promise<void>
+    save(): any
+    clear(): void
+    validate(): Promise<boolean>
+    getNodes(): any[]
+    getNodeById(id: string): any | null
+    addNode(type: string, options?: any): Promise<any>
+    removeNode(node: any): Promise<void>
+    connectNodes(source: any, target: any, options?: any): Promise<void>
+    disconnectNodes(source: any, target: any): Promise<void>
+  }
+
+  // Enhanced workflow operations
+  workflow: {
+    queue(batchCount?: number): Promise<string>
+    cancel(executionId?: string): Promise<void>
+    pause(): Promise<void>
+    resume(): Promise<void>
+    getStatus(): any
+    getHistory(): any[]
+    getQueue(): any[]
+  }
+
+  // Settings management
+  settings: {
+    get<T = any>(id: string): T
+    set(id: string, value: any): Promise<void>
+    getAll(): Record<string, any>
+    reset(id?: string): Promise<void>
+    export(): any
+    import(data: any): Promise<void>
+  }
+
+  // Command system
+  commands: {
+    execute(id: string, args?: any): Promise<any>
+    register(command: any): void
+    unregister(id: string): void
+    getAll(): any[]
+    isAvailable(id: string): boolean
+  }
+
+  // UI management
+  ui: {
+    bottomPanel: any
+    sidebar: any
+    menu: any
+    canvas: any
+    dialogs: any
+    notifications: any
+  }
+
+  // Event system
+  events: {
+    on<T = unknown>(event: string, handler: (data: T) => void): void
+    off<T = unknown>(event: string, handler?: (data: T) => void): void
+    emit<T = unknown>(event: string, data?: T): void
+    once<T = unknown>(event: string, handler: (data: T) => void): void
+  }
+
+  // API access
+  api: {
+    get(path: string, options?: any): Promise<any>
+    post(path: string, data?: any, options?: any): Promise<any>
+    put(path: string, data?: any, options?: any): Promise<any>
+    delete(path: string, options?: any): Promise<any>
+    patch(path: string, data?: any, options?: any): Promise<any>
+  }
+}
diff --git a/src/utils/versionProxies.ts b/src/utils/versionProxies.ts
new file mode 100644
index 000000000..2fd58c957
--- /dev/null
+++ b/src/utils/versionProxies.ts
@@ -0,0 +1,519 @@
+import type {
+  ComfyNodeDefLatest,
+  ComfyNodeDefV1,
+  ComfyNodeDefV1_2,
+  ComfyNodeDefV3
+} from './versionTransforms'
+
+/**
+ * Proxy-based system for synchronizing data between different API versions
+ */
+export class VersionProxies {
+  private static canonicalStore = new Map<string, ComfyNodeDefLatest>()
+  private static eventBus = new EventTarget()
+
+  /**
+   * Register a canonical node definition
+   */
+  static registerCanonicalNode(nodeId: string, nodeData: ComfyNodeDefLatest) {
+    this.canonicalStore.set(nodeId, nodeData)
+  }
+
+  /**
+   * Get canonical node data
+   */
+  static getCanonicalNode(nodeId: string): ComfyNodeDefLatest | undefined {
+    return this.canonicalStore.get(nodeId)
+  }
+
+  /**
+   * Create a V1 proxy for a node
+   */
+  static createV1Proxy(nodeId: string): ComfyNodeDefV1 {
+    const canonical = this.canonicalStore.get(nodeId)
+    if (!canonical) {
+      throw new Error(`Node ${nodeId} not found in canonical store`)
+    }
+
+    return new Proxy({} as ComfyNodeDefV1, {
+      get(target, prop: keyof ComfyNodeDefV1) {
+        return VersionProxies.transformCanonicalToV1Property(canonical, prop)
+      },
+
+      set(target, prop: keyof ComfyNodeDefV1, value) {
+        VersionProxies.transformV1PropertyToCanonical(canonical, prop, value)
+        VersionProxies.notifyChange(nodeId, prop, value)
+        return true
+      },
+
+      has(target, prop: keyof ComfyNodeDefV1) {
+        return (
+          prop in canonical ||
+          prop === 'input' ||
+          prop === 'output' ||
+          prop === 'output_is_list'
+        )
+      },
+
+      ownKeys(target) {
+        return [
+          'name',
+          'display_name',
+          'description',
+          'category',
+          'output_node',
+          'input',
+          'output',
+          'output_is_list',
+          'python_module'
+        ]
+      },
+
+      getOwnPropertyDescriptor(target, prop) {
+        return {
+          enumerable: true,
+          configurable: true,
+          value: this.get!(target, prop, target)
+        }
+      }
+    })
+  }
+
+  /**
+   * Create a V1.2 proxy for a node
+   */
+  static createV1_2Proxy(nodeId: string): ComfyNodeDefV1_2 {
+    const canonical = this.canonicalStore.get(nodeId)
+    if (!canonical) {
+      throw new Error(`Node ${nodeId} not found in canonical store`)
+    }
+
+    return new Proxy({} as ComfyNodeDefV1_2, {
+      get(target, prop: keyof ComfyNodeDefV1_2) {
+        return VersionProxies.transformCanonicalToV1_2Property(canonical, prop)
+      },
+
+      set(target, prop: keyof ComfyNodeDefV1_2, value) {
+        VersionProxies.transformV1_2PropertyToCanonical(canonical, prop, value)
+        VersionProxies.notifyChange(nodeId, prop, value)
+        return true
+      },
+
+      has(target, prop: keyof ComfyNodeDefV1_2) {
+        return (
+          prop in canonical ||
+          prop === 'input' ||
+          prop === 'output' ||
+          prop === 'output_is_list' ||
+          prop === 'inputs' ||
+          prop === 'metadata'
+        )
+      },
+
+      ownKeys(target) {
+        return [
+          'name',
+          'display_name',
+          'description',
+          'category',
+          'output_node',
+          'input',
+          'output',
+          'output_is_list',
+          'inputs',
+          'metadata',
+          'python_module'
+        ]
+      },
+
+      getOwnPropertyDescriptor(target, prop) {
+        return {
+          enumerable: true,
+          configurable: true,
+          value: this.get!(target, prop, target)
+        }
+      }
+    })
+  }
+
+  /**
+   * Create a V3 proxy for a node
+   */
+  static createV3Proxy(nodeId: string): ComfyNodeDefV3 {
+    const canonical = this.canonicalStore.get(nodeId)
+    if (!canonical) {
+      throw new Error(`Node ${nodeId} not found in canonical store`)
+    }
+
+    return new Proxy({} as ComfyNodeDefV3, {
+      get(target, prop: keyof ComfyNodeDefV3) {
+        return VersionProxies.transformCanonicalToV3Property(canonical, prop)
+      },
+
+      set(target, prop: keyof ComfyNodeDefV3, value) {
+        VersionProxies.transformV3PropertyToCanonical(canonical, prop, value)
+        VersionProxies.notifyChange(nodeId, prop, value)
+        return true
+      },
+
+      has(target, prop: keyof ComfyNodeDefV3) {
+        return (
+          prop in canonical ||
+          prop === 'schema' ||
+          prop === 'inputs' ||
+          prop === 'outputs'
+        )
+      },
+
+      ownKeys(target) {
+        return [
+          'name',
+          'display_name',
+          'description',
+          'category',
+          'output_node',
+          'schema',
+          'inputs',
+          'outputs',
+          'python_module'
+        ]
+      },
+
+      getOwnPropertyDescriptor(target, prop) {
+        return {
+          enumerable: true,
+          configurable: true,
+          value: this.get!(target, prop, target)
+        }
+      }
+    })
+  }
+
+  /**
+   * Transform canonical property to V1 format
+   */
+  private static transformCanonicalToV1Property(
+    canonical: ComfyNodeDefLatest,
+    prop: keyof ComfyNodeDefV1
+  ): any {
+    switch (prop) {
+      case 'input':
+        return canonical.input
+          ? {
+              required: canonical.input.required,
+              optional: canonical.input.optional
+            }
+          : undefined
+      case 'output':
+        return canonical.output
+      case 'output_is_list':
+        return canonical.output_is_list
+      case 'name':
+      case 'display_name':
+      case 'description':
+      case 'category':
+      case 'output_node':
+      case 'python_module':
+        return canonical[prop]
+      default:
+        return undefined
+    }
+  }
+
+  /**
+   * Transform canonical property to V1.2 format
+   */
+  private static transformCanonicalToV1_2Property(
+    canonical: ComfyNodeDefLatest,
+    prop: keyof ComfyNodeDefV1_2
+  ): any {
+    switch (prop) {
+      case 'inputs':
+        if (!canonical.input) return undefined
+        return [
+          ...Object.entries(canonical.input.required || {}).map(
+            ([name, spec]) => ({
+              name,
+              type: this.inferTypeFromSpec(spec),
+              required: true,
+              spec,
+              options: Array.isArray(spec) ? spec : undefined
+            })
+          ),
+          ...Object.entries(canonical.input.optional || {}).map(
+            ([name, spec]) => ({
+              name,
+              type: this.inferTypeFromSpec(spec),
+              required: false,
+              spec,
+              options: Array.isArray(spec) ? spec : undefined
+            })
+          )
+        ]
+      case 'metadata':
+        return {
+          version: canonical.api_version,
+          author: 'Unknown',
+          description: canonical.description
+        }
+      default:
+        return this.transformCanonicalToV1Property(
+          canonical,
+          prop as keyof ComfyNodeDefV1
+        )
+    }
+  }
+
+  /**
+   * Transform canonical property to V3 format
+   */
+  private static transformCanonicalToV3Property(
+    canonical: ComfyNodeDefLatest,
+    prop: keyof ComfyNodeDefV3
+  ): any {
+    switch (prop) {
+      case 'schema': {
+        const requiredInputs = Object.keys(canonical.input?.required || {})
+        return {
+          type: 'object',
+          properties: {
+            ...(canonical.input?.required || {}),
+            ...(canonical.input?.optional || {})
+          },
+          required: requiredInputs
+        }
+      }
+      case 'inputs': {
+        if (!canonical.input) return []
+        const requiredInputs2 = Object.entries(canonical.input.required || {})
+        const optionalInputs = Object.entries(canonical.input.optional || {})
+        return [
+          ...requiredInputs2.map(([name, spec]) => ({
+            name,
+            type: this.inferTypeFromSpec(spec),
+            required: true,
+            schema: spec
+          })),
+          ...optionalInputs.map(([name, spec]) => ({
+            name,
+            type: this.inferTypeFromSpec(spec),
+            required: false,
+            schema: spec
+          }))
+        ]
+      }
+      case 'outputs':
+        return (
+          canonical.output?.map((type, index) => ({
+            name: `output_${index}`,
+            type,
+            is_list: canonical.output_is_list?.[index] || false
+          })) || []
+        )
+      case 'name':
+      case 'display_name':
+      case 'description':
+      case 'category':
+      case 'output_node':
+      case 'python_module':
+        return canonical[prop]
+      default:
+        return undefined
+    }
+  }
+
+  /**
+   * Transform V1 property changes back to canonical format
+   */
+  private static transformV1PropertyToCanonical(
+    canonical: ComfyNodeDefLatest,
+    prop: keyof ComfyNodeDefV1,
+    value: any
+  ): void {
+    switch (prop) {
+      case 'input':
+        canonical.input = value
+          ? {
+              required: value.required,
+              optional: value.optional
+            }
+          : undefined
+        break
+      case 'output':
+        canonical.output = value
+        break
+      case 'output_is_list':
+        canonical.output_is_list = value
+        break
+      case 'name':
+      case 'display_name':
+      case 'description':
+      case 'category':
+      case 'output_node':
+      case 'python_module':
+        ;(canonical as any)[prop] = value
+        break
+    }
+  }
+
+  /**
+   * Transform V1.2 property changes back to canonical format
+   */
+  private static transformV1_2PropertyToCanonical(
+    canonical: ComfyNodeDefLatest,
+    prop: keyof ComfyNodeDefV1_2,
+    value: any
+  ): void {
+    switch (prop) {
+      case 'inputs':
+        if (Array.isArray(value)) {
+          const required: Record<string, any> = {}
+          const optional: Record<string, any> = {}
+
+          value.forEach((input) => {
+            if (input.required) {
+              required[input.name] = input.spec
+            } else {
+              optional[input.name] = input.spec
+            }
+          })
+
+          canonical.input = {
+            required: Object.keys(required).length > 0 ? required : undefined,
+            optional: Object.keys(optional).length > 0 ? optional : undefined
+          }
+        }
+        break
+      case 'metadata':
+        if (value && typeof value === 'object') {
+          canonical.api_version = value.version
+          canonical.description = value.description || canonical.description
+        }
+        break
+      default:
+        this.transformV1PropertyToCanonical(
+          canonical,
+          prop as keyof ComfyNodeDefV1,
+          value
+        )
+    }
+  }
+
+  /**
+   * Transform V3 property changes back to canonical format
+   */
+  private static transformV3PropertyToCanonical(
+    canonical: ComfyNodeDefLatest,
+    prop: keyof ComfyNodeDefV3,
+    value: any
+  ): void {
+    switch (prop) {
+      case 'schema':
+        if (value && typeof value === 'object') {
+          const required: Record<string, any> = {}
+          const optional: Record<string, any> = {}
+
+          Object.entries(value.properties || {}).forEach(([name, spec]) => {
+            if (value.required?.includes(name)) {
+              required[name] = spec
+            } else {
+              optional[name] = spec
+            }
+          })
+
+          canonical.input = {
+            required: Object.keys(required).length > 0 ? required : undefined,
+            optional: Object.keys(optional).length > 0 ? optional : undefined
+          }
+        }
+        break
+      case 'inputs':
+        if (Array.isArray(value)) {
+          const required: Record<string, any> = {}
+          const optional: Record<string, any> = {}
+
+          value.forEach((input) => {
+            if (input.required) {
+              required[input.name] = input.schema
+            } else {
+              optional[input.name] = input.schema
+            }
+          })
+
+          canonical.input = {
+            required: Object.keys(required).length > 0 ? required : undefined,
+            optional: Object.keys(optional).length > 0 ? optional : undefined
+          }
+        }
+        break
+      case 'outputs':
+        if (Array.isArray(value)) {
+          canonical.output = value.map((output) => output.type)
+          canonical.output_is_list = value.map((output) => output.is_list)
+        }
+        break
+      case 'name':
+      case 'display_name':
+      case 'description':
+      case 'category':
+      case 'output_node':
+      case 'python_module':
+        ;(canonical as any)[prop] = value
+        break
+    }
+  }
+
+  /**
+   * Notify about data changes
+   */
+  private static notifyChange(nodeId: string, prop: string, value: any): void {
+    this.eventBus.dispatchEvent(
+      new CustomEvent('nodedef-changed', {
+        detail: { nodeId, prop, value }
+      })
+    )
+  }
+
+  /**
+   * Add event listener for data changes
+   */
+  static addEventListener(type: string, listener: EventListener): void {
+    this.eventBus.addEventListener(type, listener)
+  }
+
+  /**
+   * Remove event listener
+   */
+  static removeEventListener(type: string, listener: EventListener): void {
+    this.eventBus.removeEventListener(type, listener)
+  }
+
+  /**
+   * Infer type from input specification
+   */
+  private static inferTypeFromSpec(spec: any): string {
+    if (Array.isArray(spec)) {
+      return 'combo'
+    }
+
+    if (typeof spec === 'object' && spec !== null) {
+      if (spec.type) {
+        return spec.type
+      }
+      if (spec[0] === 'INT') {
+        return 'int'
+      }
+      if (spec[0] === 'FLOAT') {
+        return 'float'
+      }
+      if (spec[0] === 'STRING') {
+        return 'string'
+      }
+      if (spec[0] === 'BOOLEAN') {
+        return 'boolean'
+      }
+    }
+
+    return 'unknown'
+  }
+}
diff --git a/src/utils/versionTransforms.ts b/src/utils/versionTransforms.ts
new file mode 100644
index 000000000..b94aaaaee
--- /dev/null
+++ b/src/utils/versionTransforms.ts
@@ -0,0 +1,250 @@
+import type { ComfyNodeDef } from '@/schemas/nodeDefSchema'
+
+// Type definitions for different API versions
+export interface ComfyNodeDefV1 {
+  name: string
+  display_name?: string
+  description?: string
+  category?: string
+  output_node?: boolean
+  input?: {
+    required?: Record<string, any>
+    optional?: Record<string, any>
+  }
+  output?: string[]
+  output_is_list?: boolean[]
+  python_module?: string
+}
+
+export interface ComfyNodeDefV1_2 extends ComfyNodeDefV1 {
+  inputs?: Array<{
+    name: string
+    type: string
+    required: boolean
+    options?: any
+    spec?: any
+  }>
+  metadata?: {
+    version?: string
+    author?: string
+    description?: string
+  }
+}
+
+export interface ComfyNodeDefV3 {
+  name: string
+  display_name?: string
+  description?: string
+  category?: string
+  output_node?: boolean
+  schema: {
+    type: 'object'
+    properties: Record<string, any>
+    required?: string[]
+  }
+  inputs: Array<{
+    name: string
+    type: string
+    required: boolean
+    schema: any
+  }>
+  outputs: Array<{
+    name: string
+    type: string
+    is_list: boolean
+  }>
+  python_module?: string
+}
+
+// Use current ComfyNodeDef as the canonical format
+export type ComfyNodeDefLatest = ComfyNodeDef
+
+/**
+ * Transforms node definitions between different API versions
+ */
+export class VersionTransforms {
+  /**
+   * Transform API responses to all supported versions
+   */
+  static transformToAllVersions(currentData: any, v3Data: any = null) {
+    // Use current data as canonical since it's our primary source
+    const canonical = currentData || {}
+
+    return {
+      canonical,
+      v1: this.canonicalToV1(canonical),
+      v1_2: this.canonicalToV1_2(canonical),
+      v3: v3Data || this.canonicalToV3(canonical)
+    }
+  }
+
+  /**
+   * Transform canonical format to v1 format
+   */
+  static canonicalToV1(
+    canonical: Record<string, ComfyNodeDefLatest>
+  ): Record<string, ComfyNodeDefV1> {
+    const v1Nodes: Record<string, ComfyNodeDefV1> = {}
+
+    for (const [nodeName, nodeData] of Object.entries(canonical)) {
+      v1Nodes[nodeName] = {
+        name: nodeData.name,
+        display_name: nodeData.display_name,
+        description: nodeData.description,
+        category: nodeData.category,
+        output_node: nodeData.output_node,
+        python_module: nodeData.python_module,
+        input: nodeData.input
+          ? {
+              required: nodeData.input.required,
+              optional: nodeData.input.optional
+            }
+          : undefined,
+        output: nodeData.output,
+        output_is_list: nodeData.output_is_list
+      }
+    }
+
+    return v1Nodes
+  }
+
+  /**
+   * Transform canonical format to v1.2 format
+   */
+  static canonicalToV1_2(
+    canonical: Record<string, ComfyNodeDefLatest>
+  ): Record<string, ComfyNodeDefV1_2> {
+    const v1_2Nodes: Record<string, ComfyNodeDefV1_2> = {}
+
+    for (const [nodeName, nodeData] of Object.entries(canonical)) {
+      const v1Node = this.canonicalToV1({ [nodeName]: nodeData })[nodeName]
+
+      v1_2Nodes[nodeName] = {
+        ...v1Node,
+        inputs: nodeData.input
+          ? [
+              ...Object.entries(nodeData.input.required || {}).map(
+                ([name, spec]) => ({
+                  name,
+                  type: this.inferTypeFromSpec(spec),
+                  required: true,
+                  spec,
+                  options: Array.isArray(spec) ? spec : undefined
+                })
+              ),
+              ...Object.entries(nodeData.input.optional || {}).map(
+                ([name, spec]) => ({
+                  name,
+                  type: this.inferTypeFromSpec(spec),
+                  required: false,
+                  spec,
+                  options: Array.isArray(spec) ? spec : undefined
+                })
+              )
+            ]
+          : undefined,
+        metadata: {
+          version: nodeData.api_version,
+          author: 'Unknown',
+          description: nodeData.description
+        }
+      }
+    }
+
+    return v1_2Nodes
+  }
+
+  /**
+   * Transform canonical format to v3 format
+   */
+  static canonicalToV3(
+    canonical: Record<string, ComfyNodeDefLatest>
+  ): Record<string, ComfyNodeDefV3> {
+    const v3Nodes: Record<string, ComfyNodeDefV3> = {}
+
+    for (const [nodeName, nodeData] of Object.entries(canonical)) {
+      const requiredInputs = Object.keys(nodeData.input?.required || {})
+      const optionalInputs = Object.keys(nodeData.input?.optional || {})
+
+      v3Nodes[nodeName] = {
+        name: nodeData.name,
+        display_name: nodeData.display_name,
+        description: nodeData.description,
+        category: nodeData.category,
+        output_node: nodeData.output_node,
+        python_module: nodeData.python_module,
+        schema: {
+          type: 'object',
+          properties: {
+            ...(nodeData.input?.required || {}),
+            ...(nodeData.input?.optional || {})
+          },
+          required: requiredInputs
+        },
+        inputs: [
+          ...requiredInputs.map((name) => ({
+            name,
+            type: this.inferTypeFromSpec(nodeData.input!.required![name]),
+            required: true,
+            schema: nodeData.input!.required![name]
+          })),
+          ...optionalInputs.map((name) => ({
+            name,
+            type: this.inferTypeFromSpec(nodeData.input!.optional![name]),
+            required: false,
+            schema: nodeData.input!.optional![name]
+          }))
+        ],
+        outputs:
+          nodeData.output?.map((type, index) => ({
+            name: `output_${index}`,
+            type,
+            is_list: nodeData.output_is_list?.[index] || false
+          })) || []
+      }
+    }
+
+    return v3Nodes
+  }
+
+  /**
+   * Infer type from input specification
+   */
+  private static inferTypeFromSpec(spec: any): string {
+    if (Array.isArray(spec)) {
+      return 'combo'
+    }
+
+    if (typeof spec === 'object' && spec !== null) {
+      if (spec.type) {
+        return spec.type
+      }
+      if (spec[0] === 'INT') {
+        return 'int'
+      }
+      if (spec[0] === 'FLOAT') {
+        return 'float'
+      }
+      if (spec[0] === 'STRING') {
+        return 'string'
+      }
+      if (spec[0] === 'BOOLEAN') {
+        return 'boolean'
+      }
+    }
+
+    return 'unknown'
+  }
+
+  /**
+   * Merge current and v3 data to create canonical format
+   */
+  private static createCanonicalFormat(
+    currentData: any,
+    v3Data: any
+  ): Record<string, ComfyNodeDefLatest> {
+    // For now, use current data as canonical
+    // In the future, we might merge v3 data for enhanced information
+    return currentData || {}
+  }
+}