Supabase Auth now supports Anonymous Sign-ins

Supabase Auth now supports anonymous sign-ins, one of our most-requested features by the community.

Anonymous sign-ins can be used to create temporary users who haven’t signed up for your application yet. This lowers the friction for new users to try out your product since they don’t have to provide any signup credentials.

Enabling Anonymous sign-ins#

You can enable anonymous sign-ins for your project today from the dashboard:

For local development, upgrade your Supabase CLI and add the config to the config.toml file:

You can create an anonymous user through the Javascript, Flutter or Swift SDKs today. Here’s how you can create an anonymous user using supabase-js .

Terminology#

Profiles created with anonymous sign-ins are also authenticated!

Once you call .signInAnonymously() you have moved the user into an authentication flow, and we treat them like a signed in user:

Restricting access for anonymous users#

Like a permanent user, anonymous users are persisted in the auth.users table:

id	role	email	is_anonymous
e053e470-afa1-4625-8963-37adb862fd11	authenticated	NULL	true
5563108e-ac81-4063-9288-4f3db068efa1	authenticated	luke@starwars.com	false

An anonymous user can be identified by the is_anonymous claim returned in the user’s JWT, which is accessible from your Row Level Security policies (RLS). This is helpful if you want to limit access to certain features in your application.

For example, let’s say that we have an online forum where users can create and read posts.

Given this table to store the posts:

If we only want to allow permanent users to create posts, we can check if the user is anonymous by inspecting the JWT select auth.jwt() ->> 'is_anonymous'.

Using this function in an RLS policy:

RLS gives us full flexibility to create a variety of rules.

For example, to allow read access for permanent users for all posts and limit anonymous users to posts created today:

Convert an anonymous user to a permanent user#

At some point, an anonymous user may decide they want to create a post. This is where we prompt them to sign up for an account which converts them to a permanent user.

Supabase Auth provides 2 ways to achieve this:

1. Link an email or phone identity
2. Link an OAuth identity

Link an email or phone identity#

To link an email or phone identity:

Link an OAuth identity#

To link an OAuth identity to an anonymous user, you need to enable manual linking for your project. Learn about how identity linking works with Supabase Auth.

Once enabled, you can call the linkIdentity() method:

Impersonating an anonymous user#

When creating RLS policies to differentiate access for an anonymous user, you can leverage the user impersonation feature in the SQL editor to test out your policies:

The user management screen provides an option to filter by anonymous users, which can help to know how many anonymous users have been created.

What’s next#

Managing anonymous users can be tricky, especially when you have a lot of visitors to your site. We’re working on an “automatic clean-up” option to delete anonymous users that have been inactive for more than 30 days. In the meantime, since anonymous users are stored in the auth schema in your database, you can clean up orphaned anonymous users by running the following query:

We are also working on a linter to check your RLS policies and highlight those that allow anonymous users access - stay tuned for updates later this month!

Getting started#

• Docs: Anonymous sign-ins
• API method references: Javascript, Flutter, Swift