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 - users can upload a profile photo.

Supabase User Management example

If you get stuck while working through this guide, refer to 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.
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># You can get <project-id> from your project's dashboard URL: https://supabase.com/dashboard/project/<project-id>supabase db pull

Get the API keys

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 anon key from the API settings.

Go to the API Settings page in the Dashboard.
Find your Project URL, anon, and service_role keys on this page.

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-tscd supabase-sveltenpm 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 anon key that you copied earlier.

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VITE_SUPABASE_URL=YOUR_SUPABASE_URLVITE_SUPABASE_ANON_KEY=YOUR_SUPABASE_ANON_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'const supabaseUrl = import.meta.env.VITE_SUPABASE_URLconst supabaseAnonKey = import.meta.env.VITE_SUPABASE_ANON_KEYexport const supabase = createClient(supabaseUrl, supabaseAnonKey)

View source

App styling (optional)

Optionally, update the CSS file src/app.css to make the app look nice. You can find the full contents of this file on GitHub.

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

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

View source

Launch!

Now that you have all the components in place, update App.svelte:

src/App.svelte

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

Bonus: Profile photos

Every Supabase project is configured with Storage for managing large files like photos and videos.

Create an avatar for the user so that they can upload a profile photo. Start by creating a new component:

src/lib/Avatar.svelte

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

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And then you can add the widget to the Account page:

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<script lang="ts">  // ...  import Avatar from "./Avatar.svelte";    // ...    } finally {      loading = false;    }  // ...  };  // ...  </div>  <button    type="button"    class="button block"    onclick={() => supabase.auth.signOut()}  >    Sign Out  </button></form>

View source

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 the API keys

Building the app

Initialize a Svelte app

src/supabaseClient.ts

App styling (optional)

src/lib/Auth.svelte

Account page

Launch!

src/App.svelte

Bonus: Profile photos

Create an upload widget

src/lib/Avatar.svelte

Add the new widget

Is this helpful?

Build a User Management App with Svelte

Project setup#

Create a project#

Set up the database schema#

Get the 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#

Launch!#

src/App.svelte

Bonus: Profile photos#

Create an upload widget#

src/lib/Avatar.svelte

Add the new widget#

Is this helpful?

Project setup

Create a project

Set up the database schema

Get the API keys

Building the app

Initialize a Svelte app

App styling (optional)

Set up a login component

Account page

Launch!

Bonus: Profile photos

Create an upload widget

Add the new widget