How to create a streaming API in Node.js using Express

In this article, we'll show you how to create a streaming API in Node.js using Express. Here, we'll stream the randomly generated string to create a streaming API.

Refer to the following article if you don't know about the stream API:
Understanding Node.js Stream API: A Comprehensive Guide to Stream Processing in Node.js

Demo Application

Output - How to create a streaming API in Node.js using Express - Clue Mediator

Steps to create a streaming API in Node.js

1. Set up a new Node.js project
2. Create an Express server
3. Route to handle the streaming API
4. Run the server

1. Set up a new Node.js project

• Initialize a new Node.js project by running npm init in your project's root directory.
• Install Express by running npm install express.

2. Create an Express server

Create a new JavaScript file, e.g., server.js, and require the necessary dependencies:

const express = require('express');
const app = express();

...
...

const port = 3000; // Set the desired port number
app.listen(port, () => {
  console.log(`Server is listening on port ${port}`);
});

3. Route to handle the streaming API

Define the following route to handle the streaming API.

server.js

// server.js

const express = require('express');
const app = express();

app.get('/stream', (req, res) => {

  res.writeHead(200, {
    'Content-Type': 'text/plain; charset=utf-8',
    'Transfer-Encoding': 'chunked',
    'X-Content-Type-Options': 'nosniff'
  });

  const interval = setInterval(() => {
    const data1 = Math.random().toString(36).substring(2, 8);
    const data2 = Math.random().toString(36).substring(2, 8);
    res.write(`${data1} ${data2}`);
  }, 100);

  setTimeout(() => {
    clearInterval(interval);
    res.end();
  }, 10000);

});

const port = 3000;
app.listen(port, () => {
  console.log(`Server is listening on port ${port}`);
});

4. Run the server

In the terminal, navigate to your project's root directory and Run node server.js to start the server.

Now, when you access http://localhost:3000/stream in a web browser or make a request to that URL programmatically, the server will respond with a streaming API. In this example, the server streams the random text every 100 milliseconds. You can modify the streaming logic and response as per your requirements.

I hope you find this article helpful.
Thank you for reading. Happy Coding..!! 🙂

Demo & Source Code

GitHub Repository