Menggunakan OpenAI API

OpenAI API adalah cara paling umum mengintegrasikan AI ke web app. SDK tersedia untuk Node.js, Python, dan bahasa lain.

Setup

npm install openai

// .env
OPENAI_API_KEY=sk-...

Chat Completion

import OpenAI from "openai";

const openai = new OpenAI(); // reads OPENAI_API_KEY from env

const response = await openai.chat.completions.create({
  model: "gpt-4o",
  messages: [
    { role: "system", content: "Kamu adalah asisten coding." },
    { role: "user", content: "Bagaimana cara membuat REST API di Express?" },
  ],
  temperature: 0.7,
  max_tokens: 1000,
});

console.log(response.choices[0].message.content);

Multi-turn Conversation

// Kirim seluruh history percakapan
const messages = [
  { role: "system", content: "Asisten coding." },
  { role: "user", content: "Apa itu middleware?" },
  { role: "assistant", content: "Middleware adalah fungsi..." },
  { role: "user", content: "Berikan contoh di Express" }, // follow-up
];

const response = await openai.chat.completions.create({
  model: "gpt-4o",
  messages,
});

Cost Management

// response.usage menunjukkan token usage
{
  prompt_tokens: 150,     // input
  completion_tokens: 320, // output
  total_tokens: 470
}

// GPT-4o: ~$2.50 per 1M input tokens, ~$10 per 1M output tokens
// Estimasi: 1000 percakapan sederhana ≈ $1-5

Error Handling

try {
  const response = await openai.chat.completions.create({...});
} catch (err) {
  if (err.status === 429) {
    // Rate limited — implement exponential backoff
  } else if (err.status === 401) {
    // Invalid API key
  }
}