SvelteKit on AWS with SST

We are going to create a SvelteKit app, add an S3 Bucket for file uploads, and deploy it to AWS using SST.

View source

You can view the source of this example in our repo.

Before you get started, make sure to configure your AWS credentials.

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1. Create a project

Let’s start by creating our app.

npm create svelte@latest my-svelte-app
cd my-svelte-app

We are picking the Skeleton project and Yes, using TypeScript syntax options.

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Init SST

Now let’s initialize SST in our app.

npx sst@latest init
npm install

Select the defaults and pick AWS. This’ll create a sst.config.ts file in your project root.

It’ll also ask you to update your svelte.config.mjs with something like this.

svelte.config.mjs

import adapter from '@sveltejs/adapter-auto';
import adapter from "svelte-kit-sst";

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Start dev mode

Run the following to start dev mode. This’ll start SST and your SvelteKit app.

npx sst dev

Once complete, click on MyWeb in the sidebar and open your SvelteKit app in your browser.

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2. Add an S3 Bucket

Let’s allow public access to our S3 Bucket for file uploads. Update your sst.config.ts.

sst.config.ts

const bucket = new sst.aws.Bucket("MyBucket", {
  access: "public"
});

Add this above the SvelteKit component.

Link the bucket

Now, link the bucket to our SvelteKit app.

sst.config.ts

new sst.aws.SvelteKit("MyWeb", {
  link: [bucket]
});

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3. Create an upload form

Let’s add a file upload form. Replace your src/routes/+page.svelte. This will upload a file to a given pre-signed upload URL.

src/routes/+page.svelte

<script>
  /** @type {import('./$types').PageData} */
  export let data;

  const handleSubmit = async (e) => {
    const formData = new FormData(e.target);
    const file = formData.get("file");

    const image = await fetch(data.url, {
      body: file,
      method: "PUT",
      headers: {
        "Content-Type": file.type,
        "Content-Disposition": `attachment; filename="${file.name}"`,
      },
    });

    window.location.href = image.url.split("?")[0];
  };
</script>

<section>
  <form on:submit|preventDefault={handleSubmit}>
    <input name="file" type="file" accept="image/png, image/jpeg" />
    <button type="submit">Upload</button>
  </form>
</section>

Add some styles.

src/routes/+page.svelte

<style>
  section {
    flex: 0.6;
    display: flex;
    padding-top: 4rem;
    align-items: center;
    flex-direction: column;
    justify-content: center;
  }
</style>

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4. Generate a pre-signed URL

When our route loads, we’ll generate a pre-signed URL for S3 and our form will upload to it. Create a new +page.server.ts and add the following.

src/routes/+page.server.ts

/** @type {import('./$types').PageServerLoad} */
export async function load() {
  const command = new PutObjectCommand({
    Key: crypto.randomUUID(),
    Bucket: Resource.MyBucket.name,
  });
  const url = await getSignedUrl(new S3Client({}), command);

  return { url };
}

Tip

We are directly accessing our S3 bucket with Resource.MyBucket.name.

Add the relevant imports.

src/routes/+page.server.ts

import { Resource } from "sst";
import { getSignedUrl } from "@aws-sdk/s3-request-presigner";
import { S3Client, PutObjectCommand } from "@aws-sdk/client-s3";

And install the npm packages.

npm install @aws-sdk/client-s3 @aws-sdk/s3-request-presigner

Head over to the local SvelteKit app in your browser, http://localhost:5173 and try uploading an image. You should see it upload and then download the image.

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5. Deploy your app

Now let’s deploy your app to AWS.

npx sst deploy --stage production

You can use any stage name here but it’s good to create a new stage for production.

Congrats! Your app should now be live!

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Connect the console

As a next step, you can setup the SST Console to git push to deploy your app and monitor it for any issues.

You can create a free account and connect it to your AWS account.