Connect an Express application to Neon

This guide describes how to create a Neon project and connect to it from an Express application. Examples are provided for using the Neon serverless driver, node-postgres and Postgres.js clients. Use the client you prefer.

To connect to Neon from an Express application:

1. Create a Neon Project
2. Create an Express project and add dependencies
3. Store your Neon credentials
4. Configure the Postgres client
5. Run app.js

Create a Neon project

If you do not have one already, create a Neon project.

1. Navigate to the Projects page in the Neon Console.
2. Click New Project.
3. Specify your project settings and click Create Project.

Create an Express project and add dependencies

1. Create an Express project and change to the newly created directory.

   mkdir neon-express-example
   cd neon-express-example
   npm init -y
   npm install express

2. Add project dependencies using one of the following commands:

   Neon serverless driver

   node-postgres

   postgres.js

   npm install @neondatabase/serverless dotenv

Store your Neon credentials

Add a .env file to your project directory and add your Neon connection details to it. You can find the connection details for your database in the Connection Details widget on the Neon Dashboard. Please select Node.js from the Connection string dropdown. For more information, see Connect from any application.

DATABASE_URL="postgres://<user>:<password>@<endpoint_hostname>.neon.tech:<port>/<dbname>?sslmode=require"

Configure the Postgres client

Add an index.js file to your project directory and add the following code snippet to connect to your Neon database:

require('dotenv').config();

const express = require('express');
const { neon } = require('@neondatabase/serverless');

const app = express();
const PORT = process.env.PORT || 4242;

app.get('/', async (_, res) => {
  const sql = neon(`${process.env.DATABASE_URL}`);
  const response = await sql`SELECT version()`;
  const { version } = response[0];
  res.json({ version });
});

app.listen(PORT, () => {
  console.log(`Listening to http://localhost:${PORT}`);
});

Run index.js

Run node index.js to view the result on localhost:4242 as follows:

{ version: 'PostgreSQL 16.0 on x86_64-pc-linux-gnu, compiled by gcc (Debian 10.2.1-6) 10.2.1 20210110, 64-bit' }

Source code

You can find the source code for the application described in this guide on GitHub.

• Get started with Express and Neon

  Get started with Express and Neon