Frontier · backend

Use Claude Opus 4 with Express.js

Updated 2026-05-21 · By XALEN

1. Install

npm install xalen-sdk express

2. Code

const express = require('express');
const XALEN = require('xalen-sdk');

const app = express();
app.use(express.json());
const client = new XALEN({ apiKey: 'xln_test_YOUR_KEY' });

app.post('/chat', async (req, res) => {
  const response = await client.chat.completions.create({
    model: 'claude-opus-4',
    messages: req.body.messages
  });
  res.json({ reply: response.choices[0].message.content });
});

app.listen(3000);

Claude Opus 4 with Other Frameworks

Other Models with Express.js

Last updated: 2026-05-21