diff --git a/frontend/src/api/editorAI.ts b/frontend/src/api/editorAI.ts
new file mode 100644
index 00000000..a9d55800
--- /dev/null
+++ b/frontend/src/api/editorAI.ts
@@ -0,0 +1,42 @@
+import { apiClient } from './client'
+import type { AIActionType } from '@/types'
+
+export interface SendMessageParams {
+  sessionId: string
+  content: string
+  actionType?: AIActionType
+  focalNodeId?: string | null
+}
+
+export const editorAIApi = {
+  startSession: async (flowType: 'troubleshooting' | 'procedural', treeId?: string) => {
+    const { data } = await apiClient.post('/ai/chat/sessions', {
+      flow_type: flowType,
+      tree_id: treeId,
+    })
+    return data
+  },
+
+  sendMessage: async ({ sessionId, content, actionType, focalNodeId }: SendMessageParams) => {
+    const { data } = await apiClient.post(`/ai/chat/sessions/${sessionId}/messages`, {
+      content,
+      action_type: actionType || 'open_chat',
+      focal_node_id: focalNodeId,
+    })
+    return data
+  },
+
+  getSession: async (sessionId: string) => {
+    const { data } = await apiClient.get(`/ai/chat/sessions/${sessionId}`)
+    return data
+  },
+
+  generateFull: async (sessionId: string) => {
+    const { data } = await apiClient.post(`/ai/chat/sessions/${sessionId}/generate`)
+    return data
+  },
+
+  abandonSession: async (sessionId: string) => {
+    await apiClient.delete(`/ai/chat/sessions/${sessionId}`)
+  },
+}
diff --git a/frontend/src/hooks/useEditorAI.ts b/frontend/src/hooks/useEditorAI.ts
new file mode 100644
index 00000000..57f6cf64
--- /dev/null
+++ b/frontend/src/hooks/useEditorAI.ts
@@ -0,0 +1,151 @@
+import { useState, useCallback, useRef } from 'react'
+import { editorAIApi } from '@/api/editorAI'
+import type {
+  AIActionType,
+  EditorAIChatMessage,
+  AISuggestion,
+  ContextMenuPosition,
+} from '@/types'
+
+interface UseEditorAIOptions {
+  flowType: 'troubleshooting' | 'procedural'
+  treeId?: string | null
+}
+
+export function useEditorAI({ flowType, treeId }: UseEditorAIOptions) {
+  const [isOpen, setIsOpen] = useState(false)
+  const [focalNodeId, setFocalNodeId] = useState<string | null>(null)
+  const [contextMenu, setContextMenu] = useState<{
+    position: ContextMenuPosition
+    nodeId: string
+  } | null>(null)
+  const [sessionId, setSessionId] = useState<string | null>(null)
+  const [messages, setMessages] = useState<EditorAIChatMessage[]>([])
+  const [input, setInput] = useState('')
+  const [isLoading, setIsLoading] = useState(false)
+  const [suggestions, setSuggestions] = useState<AISuggestion[]>([])
+
+  const pendingActionRef = useRef<AIActionType>('open_chat')
+
+  const ensureSession = useCallback(async () => {
+    if (sessionId) return sessionId
+    try {
+      const result = await editorAIApi.startSession(flowType, treeId || undefined)
+      setSessionId(result.session_id)
+      if (result.greeting) {
+        setMessages((prev) => [
+          ...prev,
+          {
+            role: 'assistant' as const,
+            content: result.greeting,
+            timestamp: new Date().toISOString(),
+          },
+        ])
+      }
+      return result.session_id
+    } catch {
+      return null
+    }
+  }, [sessionId, flowType, treeId])
+
+  const openPanel = useCallback((nodeId?: string, actionType?: AIActionType) => {
+    setIsOpen(true)
+    if (nodeId) setFocalNodeId(nodeId)
+    if (actionType) pendingActionRef.current = actionType
+  }, [])
+
+  const closePanel = useCallback(() => {
+    setIsOpen(false)
+    setContextMenu(null)
+  }, [])
+
+  const openContextMenu = useCallback((e: React.MouseEvent, nodeId: string) => {
+    e.preventDefault()
+    e.stopPropagation()
+    setContextMenu({ position: { x: e.clientX, y: e.clientY }, nodeId })
+  }, [])
+
+  const closeContextMenu = useCallback(() => {
+    setContextMenu(null)
+  }, [])
+
+  const sendMessage = useCallback(async () => {
+    if (!input.trim() || isLoading) return
+
+    const currentInput = input
+    const currentAction = pendingActionRef.current
+    const currentFocalNodeId = focalNodeId
+
+    const userMessage: EditorAIChatMessage = {
+      role: 'user',
+      content: currentInput,
+      timestamp: new Date().toISOString(),
+      action_type: currentAction,
+    }
+    setMessages((prev) => [...prev, userMessage])
+    setInput('')
+    setIsLoading(true)
+
+    try {
+      const sid = await ensureSession()
+      if (!sid) return
+
+      const result = await editorAIApi.sendMessage({
+        sessionId: sid,
+        content: currentInput,
+        actionType: currentAction,
+        focalNodeId: currentFocalNodeId,
+      })
+
+      setMessages((prev) => [
+        ...prev,
+        {
+          role: 'assistant',
+          content: result.content,
+          timestamp: new Date().toISOString(),
+        },
+      ])
+    } catch {
+      setMessages((prev) => [
+        ...prev,
+        {
+          role: 'assistant',
+          content: 'Sorry, something went wrong. Please try again.',
+          timestamp: new Date().toISOString(),
+        },
+      ])
+    } finally {
+      setIsLoading(false)
+      pendingActionRef.current = 'open_chat'
+    }
+  }, [input, isLoading, ensureSession, focalNodeId])
+
+  const triggerAction = useCallback(
+    (nodeId: string, actionType: AIActionType, prompt: string) => {
+      setFocalNodeId(nodeId)
+      pendingActionRef.current = actionType
+      setInput(prompt)
+      setIsOpen(true)
+    },
+    []
+  )
+
+  return {
+    isOpen,
+    openPanel,
+    closePanel,
+    focalNodeId,
+    setFocalNodeId,
+    contextMenu,
+    openContextMenu,
+    closeContextMenu,
+    messages,
+    input,
+    setInput,
+    sendMessage,
+    isLoading,
+    suggestions,
+    setSuggestions,
+    triggerAction,
+  }
+}