gh-jezweb-claude-skills-skills-google-gemini-api/references/sdk-migration-guide.md

SDK Migration Guide

From: @google/generative-ai (DEPRECATED) To: @google/genai (CURRENT)

Deadline: November 30, 2025 (deprecated SDK sunset)

---

Why Migrate?

The @google/generative-ai SDK is deprecated and will stop receiving updates on November 30, 2025.

The new @google/genai SDK:

• ✅ Works with both Gemini API and Vertex AI
• ✅ Supports Gemini 2.0+ features
• ✅ Better TypeScript support
• ✅ Unified API across platforms
• ✅ Active development and updates

---

Migration Steps

1. Update Package

# Remove deprecated SDK
npm uninstall @google/generative-ai

# Install current SDK
npm install @google/genai@1.27.0

2. Update Imports

Old (DEPRECATED):

import { GoogleGenerativeAI } from '@google/generative-ai';

const genAI = new GoogleGenerativeAI(apiKey);
const model = genAI.getGenerativeModel({ model: 'gemini-2.5-flash' });

New (CURRENT):

import { GoogleGenAI } from '@google/genai';

const ai = new GoogleGenAI({ apiKey });
// No need to get model separately

3. Update API Calls

Old:

const result = await model.generateContent(prompt);
const response = await result.response;
const text = response.text();

New:

const response = await ai.models.generateContent({
  model: 'gemini-2.5-flash',
  contents: prompt
});
const text = response.text;

4. Update Streaming

Old:

const result = await model.generateContentStream(prompt);
for await (const chunk of result.stream) {
  console.log(chunk.text());
}

New:

const response = await ai.models.generateContentStream({
  model: 'gemini-2.5-flash',
  contents: prompt
});
for await (const chunk of response) {
  console.log(chunk.text);
}

5. Update Chat

Old:

const chat = model.startChat({
  history: []
});
const result = await chat.sendMessage(message);
const response = await result.response;
console.log(response.text());

New:

const chat = await ai.models.createChat({
  model: 'gemini-2.5-flash',
  history: []
});
const response = await chat.sendMessage(message);
console.log(response.text);

---

Complete Before/After Example

Before (Deprecated SDK)

import { GoogleGenerativeAI } from '@google/generative-ai';

const genAI = new GoogleGenerativeAI(process.env.GEMINI_API_KEY);
const model = genAI.getGenerativeModel({ model: 'gemini-2.5-flash' });

// Generate
const result = await model.generateContent('Hello');
const response = await result.response;
console.log(response.text());

// Stream
const streamResult = await model.generateContentStream('Write a story');
for await (const chunk of streamResult.stream) {
  console.log(chunk.text());
}

// Chat
const chat = model.startChat();
const chatResult = await chat.sendMessage('Hi');
const chatResponse = await chatResult.response;
console.log(chatResponse.text());

After (Current SDK)

import { GoogleGenAI } from '@google/genai';

const ai = new GoogleGenAI({ apiKey: process.env.GEMINI_API_KEY });

// Generate
const response = await ai.models.generateContent({
  model: 'gemini-2.5-flash',
  contents: 'Hello'
});
console.log(response.text);

// Stream
const streamResponse = await ai.models.generateContentStream({
  model: 'gemini-2.5-flash',
  contents: 'Write a story'
});
for await (const chunk of streamResponse) {
  console.log(chunk.text);
}

// Chat
const chat = await ai.models.createChat({ model: 'gemini-2.5-flash' });
const chatResponse = await chat.sendMessage('Hi');
console.log(chatResponse.text);

---

Key Differences

Aspect	Old SDK	New SDK
Package	@google/generative-ai	@google/genai
Class	GoogleGenerativeAI	GoogleGenAI
Model Init	genAI.getGenerativeModel()	Specify in each call
Text Access	response.text() (method)	response.text (property)
Stream Iteration	result.stream	Direct iteration
Chat Creation	model.startChat()	ai.models.createChat()

---

Troubleshooting

Error: "Cannot find module '@google/generative-ai'"

Cause: Old import statement after migration

Solution: Update all imports to @google/genai

Error: "Property 'text' does not exist"

Cause: Using response.text() (method) instead of response.text (property)

Solution: Remove parentheses: response.text not response.text()

Error: "generateContent is not a function"

Cause: Trying to call methods on old model object

Solution: Use ai.models.generateContent() directly

---

Automated Migration Script

# Find all files using old SDK
rg "@google/generative-ai" --type ts

# Replace import statements
find . -name "*.ts" -exec sed -i 's/@google\/generative-ai/@google\/genai/g' {} +

# Replace class name
find . -name "*.ts" -exec sed -i 's/GoogleGenerativeAI/GoogleGenAI/g' {} +

⚠️ Note: This script handles imports but NOT API changes. Manual review required!

---

Official Resources

• Migration Guide: https://ai.google.dev/gemini-api/docs/migrate-to-genai
• New SDK Docs: https://github.com/googleapis/js-genai
• Deprecated SDK: https://github.com/google-gemini/deprecated-generative-ai-js

---

Deadline Reminder: November 30, 2025 - Deprecated SDK sunset