Pet Project: FastAPI + Next.js – Part 4, WebSockets

Welcome to the fourth installment of our pet project series, where we explore using FastAPI and Next.js together to create a web application. In this part, we will be adding WebSocket support to our application to allow real-time communication between clients and the server.

Getting started with WebSockets

WebSockets allow for full-duplex communication between a client and server, enabling real-time updates and notifications. To add WebSocket support to our project, we will be using the websockets library for Python on the server-side, and the WebSocket API on the client-side.

Setting up WebSocket support on the server

First, let’s install the websockets library by running the following command in your virtual environment:

“`bash
pip install websockets
“`

Next, we’ll create a WebSocket route in our FastAPI application to handle incoming WebSocket connections. Here’s an example of how to set up a WebSocket route in FastAPI:

“`python
from fastapi import FastAPI
import websockets

app = FastAPI()

@app.websocket(“/ws”)
async def websocket_endpoint(websocket: websockets.WebSocket):
await websocket.send(“Hello, WebSocket!”)
“`

With this route in place, clients can connect to ws://yourdomain.com/ws and send messages back and forth with the server.

Adding WebSocket support to the client

On the client-side, we’ll need to create a WebSocket connection to the server. Here’s an example of how to establish a WebSocket connection in Next.js:

“`javascript
import { useEffect } from ‘react’;

const Page = () => {
useEffect(() => {
const ws = new WebSocket(‘ws://yourdomain.com/ws’);

ws.onopen = () => {
console.log(‘Connected to WebSocket’);
};

ws.onmessage = (event) => {
console.log(‘Message from server:’, event.data);
};

return () => {
ws.close();
};
}, []);

return (

);
};

export default Page;
“`

With this code in place, your Next.js client will establish a WebSocket connection to the server and log any incoming messages from the server.

Conclusion

By adding WebSocket support to our FastAPI + Next.js project, we can now enable real-time communication between clients and the server. This opens up a wide range of possibilities for creating interactive and dynamic web applications. In the next part of our series, we’ll explore integrating a database into our project to persist data across sessions.

Stay tuned for Part 5!