Open Source · backend
Use Llama 3.1 405B with Express.js
Updated 2026-05-21 · By XALEN
How to use Llama 3.1 405B (Open Source, 405B) with Express.js. Install, authenticate, and make your first API call in minutes. Working code example included.
Model
Llama 3.1 405B
405B · 128K context · $0.08 input
Framework
Express.js
backend · npm install xalen-sdk express
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: 'llama-3-1-405b',
messages: req.body.messages
});
res.json({ reply: response.choices[0].message.content });
});
app.listen(3000);
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Get API KeyLast updated: 2026-05-21