app.js

const express = require('express');
const axios = require('axios');
const { default: PQueue } = require('p-queue');

const API_ENDPOINT = process.env.API_ENDPOINT;
const PORT = process.env.PORT || 3000;
const WORKER_CONCURRENCY = process.env.WORKER_CONCURRENCY || 5;

const app = express();
app.use(express.json());

const queue = new PQueue({ concurrency: WORKER_CONCURRENCY });

app.post('/endpoint', function(req, res) {
    queue.add(async () => {
        try {
            const response = await axios.post(API_ENDPOINT, req.body);
            res.send(response.data);
        } catch (error) {
            res.status(500).send(error.message);
        }
    });
});

app.listen(PORT, () => console.log(`Server is running on port ${PORT}`));