Month: December 2024

Getting started with AI in Node.js is simpler than you might think. The key libraries to know are:

1. OpenAI SDK

npm install openai

import OpenAI from 'openai';

const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });

const completion = await openai.chat.completions.create({
  model: 'gpt-4',
  messages: [{ role: 'user', content: 'Hello!' }]
});

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

2. LangChain.js

For more complex chains and agents:

npm install langchain

3. Hugging Face Transformers

For local model inference:

npm install @huggingface/inference

These three libraries cover 90% of AI use cases in Node.js applications.

Streaming responses from LLMs provides a much better UX. Here’s how to implement it properly:

import OpenAI from 'openai';
import { Readable } from 'stream';

const openai = new OpenAI();

async function streamChat(prompt) {
  const stream = await openai.chat.completions.create({
    model: 'gpt-4',
    messages: [{ role: 'user', content: prompt }],
    stream: true
  });

  for await (const chunk of stream) {
    const content = chunk.choices[0]?.delta?.content || '';
    process.stdout.write(content);
  }
}

await streamChat('Explain async iterators');

Express.js SSE Integration

app.get('/chat', async (req, res) => {
  res.setHeader('Content-Type', 'text/event-stream');
  res.setHeader('Cache-Control', 'no-cache');
  
  const stream = await openai.chat.completions.create({
    model: 'gpt-4',
    messages: [{ role: 'user', content: req.query.prompt }],
    stream: true
  });

  for await (const chunk of stream) {
    res.write(`data: ${JSON.stringify(chunk)}

`);
  }
  res.end();
});