Build a User Management App with Svelte

This tutorial demonstrates how to build a basic user management app. The app authenticates and identifies the user, stores their profile information in the database, and allows the user to log in, update their profile details, and upload a profile photo. The app uses:

Supabase Database - a Postgres database for storing your user data and Row Level Security so data is protected and users can only access their own information.
Supabase Auth - allow users to sign up and log in.
Supabase Storage - allow users to upload a profile photo.

Supabase User Management example

If you get stuck while working through this guide, you can find the full example on GitHub.

Project setup#

Before you start building you need to set up the Database and API. You can do this by starting a new Project in Supabase and then creating a "schema" inside the database.

Create a project#

Create a new project in the Supabase Dashboard.
Enter your project details.
Wait for the new database to launch.

Set up the database schema#

Now set up the database schema. You can use the "User Management Starter" quickstart in the SQL Editor, or you can copy/paste the SQL from below and run it.

Go to the SQL Editor page in the Dashboard.
Click User Management Starter under the Community > Quickstarts tab.
Click Run.

You can pull the database schema down to your local project by running the db pull command. Read the local development docs for detailed instructions.

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supabase link --project-ref <project-id>
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# You can get <project-id> from your project's dashboard URL: https://supabase.com/dashboard/project/<project-id>
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supabase db pull

Get API details#

Now that you've created some database tables, you are ready to insert data using the auto-generated API.

To do this, you need to get the Project URL and key from the project Connect dialog.

Read the API keys docs for a full explanation of all key types and their uses.

Changes to API keys

Supabase is changing the way keys work to improve project security and developer experience. You can read the full announcement on GitHub.

The older anon and service_role keys will work until the end of 2026 but we strongly encourage switching to and using the new publishable (sb_publishable_xxx) and secret (sb_secret_xxx) keys now.

In most cases, you can get keys from the Project's Connect dialog, but if you want a specific key, you can find them in the Settings > API Keys section of the Dashboard.

For legacy keys, copy the anon key for client-side operations and the service_role key for server-side operations from the Legacy API Keys tab.
For new keys, open the API Keys tab, if you don't have a publishable key already, click Create new API Keys, and copy the value from the Publishable key section.

Building the app#

Start building the Svelte app from scratch.

Initialize a Svelte app#

You can use the Vite Svelte TypeScript Template to initialize an app called supabase-svelte:

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npm create vite@latest supabase-svelte -- --template svelte-ts
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cd supabase-svelte
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npm install

Install the only additional dependency: supabase-js

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npm install @supabase/supabase-js

Finally, save the environment variables in a .env. All you need are the API URL and the key that you copied earlier.

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VITE_SUPABASE_URL=YOUR_SUPABASE_URL
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VITE_SUPABASE_PUBLISHABLE_KEY=YOUR_SUPABASE_PUBLISHABLE_KEY

Now you have the API credentials in place, create a helper file to initialize the Supabase client. These variables will be exposed on the browser, and that's fine since you have Row Level Security enabled on the Database.

src/supabaseClient.ts

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import { createClient } from '@supabase/supabase-js'
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const supabaseUrl = import.meta.env.VITE_SUPABASE_URL
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const supabasePublishableKey = import.meta.env.VITE_SUPABASE_PUBLISHABLE_KEY
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export const supabase = createClient(supabaseUrl, supabasePublishableKey)

View source

App styling (optional)#

Optionally, update the CSS file src/app.css to make the app look better. You can find the full contents of this file in the example repository.

Set up a Svelte component to manage logins and sign ups. It uses Magic Links, so users can sign in with their email without using passwords.

src/lib/Auth.svelte

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<script lang="ts">
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  import { supabase } from "../supabaseClient";
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  let loading = $state(false);
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  let email = $state("");
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  const handleLogin = async () => {
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    try {
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      loading = true;
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      const { error } = await supabase.auth.signInWithOtp({ email });
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      if (error) throw error;
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      alert("Check your email for login link!");
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    } catch (error) {
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      if (error instanceof Error) {
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        alert(error.message);
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      }
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    } finally {
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      loading = false;
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    }
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  };
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</script>
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<div class="row flex-center flex">
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  <div class="col-6 form-widget" aria-live="polite">
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    <h1 class="header">Supabase + Svelte</h1>
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    <p class="description">Sign in via magic link with your email below</p>
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    <form class="form-widget" onsubmit={(e) => { e.preventDefault(); handleLogin(); }}>
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      <div>
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        <label for="email">Email</label>
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        <input
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          id="email"
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          class="inputField"
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          type="email"
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          placeholder="Your email"
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          bind:value={email}
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        />
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      </div>
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      <div>
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        <button
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          type="submit"
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          class="button block"
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          aria-live="polite"
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          disabled={loading}
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        >
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          <span>{loading ? "Loading" : "Send magic link"}</span>
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        </button>
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      </div>
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    </form>
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  </div>
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</div>

View source

Account page#

After a user is signed in, allow them to edit their profile details and manage their account. Create a new component for that called Account.svelte.

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<script lang="ts">
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  import { onMount } from "svelte";
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  import type { AuthSession } from "@supabase/supabase-js";
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  import { supabase } from "../supabaseClient";
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// ...
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  interface Props {
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    session: AuthSession;
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  }
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  let { session }: Props = $props();
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  let loading = $state(false);
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  let username = $state<string | null>(null);
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  let website = $state<string | null>(null);
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  let avatarUrl = $state<string | null>(null);
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  onMount(() => {
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    getProfile();
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  });
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  const getProfile = async () => {
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    try {
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      loading = true;
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      const { user } = session;
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      const { data, error, status } = await supabase
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        .from("profiles")
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        .select("username, website, avatar_url")
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        .eq("id", user.id)
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        .single();
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      if (error && status !== 406) throw error;
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      if (data) {
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        username = data.username;
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        website = data.website;
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        avatarUrl = data.avatar_url;
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      }
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    } catch (error) {
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      if (error instanceof Error) {
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        alert(error.message);
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      }
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    } finally {
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      loading = false;
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    }
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  };
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  const updateProfile = async () => {
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    try {
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      loading = true;
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      const { user } = session;
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      const updates = {
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        id: user.id,
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        username,
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        website,
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        avatar_url: avatarUrl,
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        updated_at: new Date().toISOString(),
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      };
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      const { error } = await supabase.from("profiles").upsert(updates);
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      if (error) {
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        throw error;
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      }
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    } catch (error) {
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      if (error instanceof Error) {
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        alert(error.message);
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      }
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    } finally {
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      loading = false;
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    }
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  };
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</script>
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<form onsubmit={(e) => { e.preventDefault(); updateProfile(); }} class="form-widget">
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  <div>Email: {session.user.email}</div>
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  <div>
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    // ...
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    <label for="username">Name</label>
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    <input id="username" type="text" bind:value={username} />
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  </div>
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  <div>
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    <label for="website">Website</label>
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    <input id="website" type="text" bind:value={website} />
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  </div>
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  <div>
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    <button type="submit" class="button primary block" disabled={loading}>
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      {loading ? "Saving ..." : "Update profile"}
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    </button>
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  </div>
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  <button
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    type="button"
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    class="button block"
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    onclick={() => supabase.auth.signOut()}
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  >
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    Sign Out
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  </button>
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</form>

View source

Profile photos#

Next, add a way for users to upload a profile photo. Supabase configures every project with Storage for managing large files like photos and videos.

Start by creating a new component:

src/lib/Avatar.svelte

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<script lang="ts">
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  import { supabase } from "../supabaseClient";
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  interface Props {
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    size: number;
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    url?: string | null;
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    onupload?: () => void;
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  }
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  let { size, url = $bindable(null), onupload }: Props = $props();
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  let avatarUrl = $state<string | null>(null);
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  let uploading = $state(false);
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  let files = $state<FileList>();
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  const downloadImage = async (path: string) => {
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    try {
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      const { data, error } = await supabase.storage
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        .from("avatars")
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        .download(path);
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      if (error) {
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        throw error;
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      }
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      const url = URL.createObjectURL(data);
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      avatarUrl = url;
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    } catch (error) {
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      if (error instanceof Error) {
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        console.log("Error downloading image: ", error.message);
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      }
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    }
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  };
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  const uploadAvatar = async () => {
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    try {
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      uploading = true;
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      if (!files || files.length === 0) {
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        throw new Error("You must select an image to upload.");
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      }
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      const file = files[0];
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      const fileExt = file.name.split(".").pop();
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      const filePath = `${Math.random()}.${fileExt}`;
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      const { error } = await supabase.storage
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        .from("avatars")
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        .upload(filePath, file);
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      if (error) {
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        throw error;
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      }
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      url = filePath;
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      onupload?.();
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    } catch (error) {
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      if (error instanceof Error) {
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        alert(error.message);
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      }
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    } finally {
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      uploading = false;
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    }
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  };
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  $effect(() => {
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    if (url) downloadImage(url);
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  });
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</script>
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<div style="width: {size}px" aria-live="polite">
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  {#if avatarUrl}
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    <img
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      src={avatarUrl}
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      alt={avatarUrl ? "Avatar" : "No image"}
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      class="avatar image"
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      style="height: {size}px, width: {size}px"
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    />
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  {:else}
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    <div class="avatar no-image" style="height: {size}px, width: {size}px"></div>
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  {/if}
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  <div style="width: {size}px">
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    <label class="button primary block" for="single">
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      {uploading ? "Uploading ..." : "Upload avatar"}
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    </label>
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    <span style="display:none">
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      <input
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        type="file"
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        id="single"
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        accept="image/*"
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        bind:files
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        onchange={uploadAvatar}
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        disabled={uploading}
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      />
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    </span>
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  </div>
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</div>

View source

Update the account component#

With the Avatar component created, update src/lib/Account.svelte to include it:

src/lib/Account.svelte

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<script lang="ts">
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  import { onMount } from "svelte";
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  import type { AuthSession } from "@supabase/supabase-js";
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  import { supabase } from "../supabaseClient";
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  import Avatar from "./Avatar.svelte";
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  interface Props {
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    session: AuthSession;
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  }
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  let { session }: Props = $props();
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  let loading = $state(false);
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  let username = $state<string | null>(null);
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  let website = $state<string | null>(null);
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  let avatarUrl = $state<string | null>(null);
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  onMount(() => {
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    getProfile();
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  });
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  const getProfile = async () => {
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    try {
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      loading = true;
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      const { user } = session;
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      const { data, error, status } = await supabase
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        .from("profiles")
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        .select("username, website, avatar_url")
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        .eq("id", user.id)
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        .single();
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      if (error && status !== 406) throw error;
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      if (data) {
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        username = data.username;
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        website = data.website;
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        avatarUrl = data.avatar_url;
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      }
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    } catch (error) {
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      if (error instanceof Error) {
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        alert(error.message);
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      }
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    } finally {
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      loading = false;
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    }
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  };
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  const updateProfile = async () => {
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    try {
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      loading = true;
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      const { user } = session;
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      const updates = {
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        id: user.id,
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        username,
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        website,
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        avatar_url: avatarUrl,
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        updated_at: new Date().toISOString(),
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      };
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      const { error } = await supabase.from("profiles").upsert(updates);
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      if (error) {
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        throw error;
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      }
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    } catch (error) {
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      if (error instanceof Error) {
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        alert(error.message);
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      }
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    } finally {
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      loading = false;
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    }
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  };
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</script>
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<form onsubmit={(e) => { e.preventDefault(); updateProfile(); }} class="form-widget">
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  <div>Email: {session.user.email}</div>
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  <div>
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    <Avatar bind:url={avatarUrl} size={150} onupload={updateProfile} />
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    <label for="username">Name</label>
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    <input id="username" type="text" bind:value={username} />
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  </div>
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  <div>
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    <label for="website">Website</label>
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    <input id="website" type="text" bind:value={website} />
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  </div>
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  <div>
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    <button type="submit" class="button primary block" disabled={loading}>
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      {loading ? "Saving ..." : "Update profile"}
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    </button>
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  </div>
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  <button
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    type="button"
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    class="button block"
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    onclick={() => supabase.auth.signOut()}
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  >
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    Sign Out
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  </button>
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</form>

View source

Launch!#

With all the components in place, update App.svelte:

src/App.svelte

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<script lang="ts">
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  import { onMount } from 'svelte'
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  import { supabase } from './supabaseClient'
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  import type { AuthSession } from '@supabase/supabase-js'
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  import Account from './lib/Account.svelte'
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  import Auth from './lib/Auth.svelte'
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  let session = $state<AuthSession | null>(null)
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  onMount(() => {
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    supabase.auth.getSession().then(({ data }) => {
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      session = data.session
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    })
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    supabase.auth.onAuthStateChange((_event, _session) => {
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      session = _session
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    })
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  })
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</script>
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<div class="container" style="padding: 50px 0 100px 0">
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  {#if !session}
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  <Auth />
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  {:else}
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  <Account {session} />
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  {/if}
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</div>

View source

Once that's done, run this in a terminal window:

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npm run dev

And then open the browser to localhost:5173 and you should see the completed app.

Svelte uses Vite and the default port is 5173, Supabase uses port 3000. To change the redirection port for Supabase go to: Authentication > URL Configuration and change the Site URL to http://localhost:5173/

Supabase Svelte

At this stage you have a fully functional application!

Build a User Management App with Svelte

Project setup#

Create a project#

Set up the database schema#

Get API details#

Changes to API keys

Building the app#

Initialize a Svelte app#

src/supabaseClient.ts

App styling (optional)#

src/lib/Auth.svelte

Account page#

Profile photos#

Create an upload widget#

src/lib/Avatar.svelte

Update the account component#

src/lib/Account.svelte

Launch!#

src/App.svelte

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Build a User Management App with Svelte

Project setup#

Create a project#

Set up the database schema#

Get API details#

Changes to API keys

Building the app#

Initialize a Svelte app#

src/supabaseClient.ts

App styling (optional)#

Set up a login component#

src/lib/Auth.svelte

Account page#

Profile photos#

Create an upload widget#

src/lib/Avatar.svelte

Update the account component#

src/lib/Account.svelte

Launch!#

src/App.svelte

Is this helpful?

AI Tools