Fix Gemini API 404 Error by Migrating to Latest @google/genai SDK

backend/controllers/receiptController.js

@@ -1,16 +1,19 @@
-const Receipt = require('../models/Receipt');
-const IncomeExpense = require('../models/IncomeExpense');
-const { GoogleGenerativeAI } = require("@google/generative-ai");
-const fs = require('fs');
+const Receipt = require("../models/Receipt");
+const IncomeExpense = require("../models/IncomeExpense");
+const { GoogleGenAI } = require("@google/genai");
 
-const genAI = new GoogleGenerativeAI(process.env.GEMINI_API_KEY);
+const fs = require("fs");
+
+const client = new GoogleGenAI({
+  apiKey: process.env.GEMINI_API_KEY,
+});
 
 // Helper function to convert a file to a format Gemini can understand
 function fileToGenerativePart(path, mimeType) {
   return {
     inlineData: {
       data: fs.readFileSync(path).toString("base64"),
-      mimeType
+      mimeType,
     },
   };
 }
@@ -20,12 +23,10 @@ function fileToGenerativePart(path, mimeType) {
 // @access  Private
 const uploadReceipt = async (req, res) => {
   if (!req.file) {
-    return res.status(400).json({ message: 'Please upload a file' });
+    return res.status(400).json({ message: "Please upload a file" });
   }
 
   try {
-    const model = genAI.getGenerativeModel({ model: "gemini-1.5-flash-latest" });
-
     const prompt = `
       Analyze this receipt image. Extract the following details:
       - merchant: The name of the store or merchant.
@@ -36,24 +37,39 @@ const uploadReceipt = async (req, res) => {
       Return the result as a single, minified JSON object. For example:
       {"merchant":"Walmart","amount":42.97,"date":"2025-09-13","category":"Groceries"}
     `;
-    
+
     const imagePart = fileToGenerativePart(req.file.path, req.file.mimetype);
 
-    const result = await model.generateContent([prompt, imagePart]);
-    const response = await result.response;
-    let text = response.text();
+    const result = await client.models.generateContent({
+      model: "gemini-2.5-flash-lite",
+      contents: [{ role: "user", parts: [{ text: prompt }, imagePart] }],
+    });
+
+    const raw =
+      result.candidates?.[0]?.content?.parts?.map((p) => p.text).join("\n\n") ??
+      "";
 
-    text = text.replace(/```json/g, '').replace(/```/g, '').trim();
-    const extractedData = JSON.parse(text);
+    const cleanedText = raw
+      .replace(/^[\s`]*```json[\s`]*/i, "") // Remove opening ```json with spaces
+      .replace(/[\s`]*```$/i, "") // Remove closing ```
+      .trim();
+
+    let extractedData;
+    try {
+      extractedData = JSON.parse(cleanedText);
+    } catch (e) {
+      console.warn("[Gemini] Invalid JSON, fallback to defaults.", e);
+      extractedData = {};
+    }
 
     const newReceipt = new Receipt({
       user: req.user.id,
       fileUrl: `/uploads/${req.file.filename}`,
       extractedData: {
         amount: extractedData.amount || 0,
-        category: extractedData.category || 'Miscellaneous',
+        category: extractedData.category || "Miscellaneous",
         date: extractedData.date ? new Date(extractedData.date) : new Date(),
-        merchant: extractedData.merchant || 'Unknown Merchant',
+        merchant: extractedData.merchant || "Unknown Merchant",
       },
     });
 
@@ -73,10 +89,14 @@ const uploadReceipt = async (req, res) => {
     }
 
     res.status(201).json(savedReceipt);
-
   } catch (error) {
-    console.error('Error with Gemini API:', error);
-    res.status(500).json({ message: 'Failed to process receipt with AI', error: error.message });
+    console.error("Error with Gemini API:", error);
+    res
+      .status(500)
+      .json({
+        message: "Failed to process receipt with AI",
+        error: error.message,
+      });
   } finally {
     // Deleting the temporary file from the server
     fs.unlinkSync(req.file.path);
@@ -85,4 +105,4 @@ const uploadReceipt = async (req, res) => {
 
 module.exports = {
   uploadReceipt,
-};
+};