diff --git a/functions/src/genkit-functions/anonymousFirestoreChatbot.ts b/functions/src/genkit-functions/anonymousFirestoreChatbot.ts
new file mode 100644
index 0000000..2e03347
--- /dev/null
+++ b/functions/src/genkit-functions/anonymousFirestoreChatbot.ts
@@ -0,0 +1,89 @@
+import { prompt } from '@genkit-ai/dotprompt'
+import { firebaseAuth } from '@genkit-ai/firebase/auth'
+import * as genkitFunctions from '@genkit-ai/firebase/functions'
+import * as z from 'zod'
+import * as config from '../config/firebase'
+import { db } from '../config/firebase'
+import { chatbotInputSchema } from '../schemas/chatbotInputSchema'
+import { chatbotOutputSchema } from '../schemas/chatbotOutputSchema'
+import { isGenkitEnabled } from '../utils/genkitUtils'
+
+export const anonymousFirestoreChatbot = genkitFunctions.onFlow(
+  {
+    name: `anonymousFirestoreChatbot`,
+    httpsOptions: {
+      cors: true,
+      secrets: [config.googleAIapiKey],
+    },
+    inputSchema: z.object({
+      userId: z.string(),
+      chatId: z.string(),
+      currentQuery: z.string(),
+    }),
+    outputSchema: chatbotOutputSchema,
+    authPolicy: firebaseAuth((user) => {
+      if (user.firebase?.sign_in_provider !== `anonymous`) {
+        throw new Error(`匿名認証されたユーザーのみがアクセスできます`)
+      }
+    }),
+  },
+  async (input) => {
+    if (!(await isGenkitEnabled())) throw new Error(`Genkit が無効になっています。`)
+
+    const userDoc = await db.collection(`users`).doc(input.userId).get()
+    const userData = userDoc.data()
+
+    const chatHistoryDoc = await db.collection(`users/${input.userId}/chatHistory`).doc(input.chatId).get()
+    const chatData = chatHistoryDoc.data()
+
+    const productDoc = await db.collection(`productCatalog`).doc(chatData?.productId).get()
+    const productData = productDoc.data()
+
+    const chatbotPrompt = await prompt<z.infer<typeof chatbotInputSchema>>(`chatbot`)
+
+    try {
+      const chatbotInput = createChatbotInput(input.userId, input.currentQuery, userData, chatData, productData)
+
+      const result = await chatbotPrompt.generate({ input: chatbotInput })
+
+      return result.output()
+    } catch (error) {
+      console.error(`Error in anonymousFirestoreChatbot:`, error)
+      throw error
+    }
+  }
+)
+
+function createChatbotInput(
+  userId: string,
+  currentQuery: string,
+  userData: any,
+  chatData: any,
+  productData: any
+): z.infer<typeof chatbotInputSchema> {
+  return {
+    userId,
+    currentQuery,
+    chatHistory:
+      chatData?.messages?.map((message: any) => ({
+        role: message.role as `user` | `assistant`,
+        content: message.content,
+        timestamp: message.timestamp,
+      })) || [],
+    userProfile: {
+      name: userData?.userProfile?.name || ``,
+      preferredLanguage: userData?.userProfile?.preferredLanguage || ``,
+      accountType: userData?.userProfile?.accountType || ``,
+    },
+    productCatalog: productData
+      ? [
+          {
+            id: productData.id || ``,
+            name: productData.name || ``,
+            details: productData.details || ``,
+            price: productData.price || 0,
+          },
+        ]
+      : [],
+  }
+}
diff --git a/functions/src/utils/genkitUtils.ts b/functions/src/utils/genkitUtils.ts
new file mode 100644
index 0000000..ca3507d
--- /dev/null
+++ b/functions/src/utils/genkitUtils.ts
@@ -0,0 +1,6 @@
+import { db } from '../config/firebase'
+
+export async function isGenkitEnabled(): Promise<boolean> {
+  const appConfDoc = await db.collection(`appConf`).doc(`config`).get()
+  return appConfDoc.data()?.genkitEnabled ?? false
+}