Follow the steps below to get started with Cosmic to power content for your Express application.

Create folder and install Express

mkdir cosmic-express
cd cosmic-express
npm init
npm i express

Install the Cosmic JavaScript SDK

Install the Cosmic JavaScript SDK in the location of the codebase.

npm i @cosmicjs/sdk

Add an Object type in the Cosmic dashboard

Log in to the Cosmic dashboard and create a new Blog Posts Object type in a new or existing Project with the following metafields:

  1. Image: Image type with key image
  2. Content: Rich text with key content

Blog model

Add content

Add a few blog posts to get some content ready to be delivered.

Create a new file app.js and add the following:

// app.js
const express = require('express');
const app = express();
const port = 3000;
import { createBucketClient } from '@cosmicjs/sdk';
const cosmic = createBucketClient({
  bucketSlug: process.env.BUCKET_SLUG || '',
  readKey: process.env.BUCKET_READ_KEY || '',

app.get('/', async (req, res) => {
  const { objects: posts } = await cosmic.objects
      type: 'blog-posts',
  let html = '';
  posts?.map((post) => {
    html += `<div>
  res.set('Content-Type', 'text/html');

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);

Add your Cosmic API keys

In a new file titled .env.local add the following environment variables and make sure to switch out the values with your Cosmic API keys found in Project / API keys.

# .env.local

Start the app

Start your app with the following command, go to http://localhost:3000, and see your blog posts. Note: we are using bun which enables environment variable reading without a separate package and the ability to use ES6 imports.

bun app.js