How to Switch from Claude 4 to GPT-5 — Save 92%

Get an OpenAI API Key

Go to platform.openai.com/api-keys and create an API key. If you already have an OpenAI account, you can use your existing key.

# Set your API key
export OPENAI_API_KEY="sk-your-key-here"

Install the OpenAI SDK

You might already have this installed — OpenAI's SDK is the most popular AI SDK in the world:

# Python
pip install openai

# Node.js
npm install openai

Update Your Code

Replace the Anthropic client with the OpenAI client. The API format is nearly identical:

Python (before → after)

# ❌ Before — Claude 4 (returns 410 Gone)
import anthropic
client = anthropic.Anthropic()
response = client.messages.create(
    model="claude-4-opus",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Explain quantum computing"}]
)
print(response.content[0].text)

# ✅ After — GPT-5 (92% cheaper)
from openai import OpenAI
client = OpenAI()
response = client.chat.completions.create(
    model="gpt-5",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Explain quantum computing"}]
)
print(response.choices[0].message.content)

Node.js (before → after)

// ❌ Before — Claude 4 (returns 410 Gone)
import Anthropic from "@anthropic-ai/sdk";
const client = new Anthropic();
const response = await client.messages.create({
    model: "claude-4-sonnet",
    max_tokens: 1024,
    messages: [{ role: "user", content: "Explain quantum computing" }]
});
console.log(response.content[0].text);

// ✅ After — GPT-5 (92% cheaper)
import OpenAI from "openai";
const client = new OpenAI();
const response = await client.chat.completions.create({
    model: "gpt-5",
    max_tokens: 1024,
    messages: [{ role: "user", content: "Explain quantum computing" }]
});
console.log(response.choices[0].message.content);

Test and Deploy

Run 5-10 test calls with your existing prompts. Check that responses meet your quality requirements. Then deploy. Your app is back online — and costing 92% less.