A web page that lists Amazon S3 objects using an AWS SDK

The following code is the relevant React component that makes calls to the AWS SDK. A runnable version of the application containing this component can be found at the preceding GitHub link.

import { useEffect, useState } from "react";
import {
  ListObjectsCommand,
  type ListObjectsCommandOutput,
  S3Client,
} from "@aws-sdk/client-s3";
import { fromCognitoIdentityPool } from "@aws-sdk/credential-providers";
import "./App.css";

function App() {
  const [objects, setObjects] = useState<
    Required<ListObjectsCommandOutput>["Contents"]
  >([]);

  useEffect(() => {
    const client = new S3Client({
      region: "us-east-1",
      // Unless you have a public bucket, you'll need access to a private bucket.
      // One way to do this is to create an Amazon Cognito identity pool, attach a role to the pool,
      // and grant the role access to the 's3:GetObject' action.
      //
      // You'll also need to configure the CORS settings on the bucket to allow traffic from
      // this example site. Here's an example configuration that allows all origins. Don't
      // do this in production.
      //[
      //  {
      //    "AllowedHeaders": ["*"],
      //    "AllowedMethods": ["GET"],
      //    "AllowedOrigins": ["*"],
      //    "ExposeHeaders": [],
      //  },
      //]
      //
      credentials: fromCognitoIdentityPool({
        clientConfig: { region: "us-east-1" },
        identityPoolId: "<YOUR_IDENTITY_POOL_ID>",
      }),
    });
    const command = new ListObjectsCommand({ Bucket: "bucket-name" });
    client.send(command).then(({ Contents }) => setObjects(Contents || []));
  }, []);

  return (
    <div className="App">
      {objects.map((o) => (
        <div key={o.ETag}>{o.Key}</div>
      ))}
    </div>
  );
}

export default App;