---
title: Anonymous
description: Let users try your app without credentials, then link to a real account later.
sidebar:
  order: 7
---

`convex-auth` can create an authenticated guest session with no email, password, or OAuth provider. The user gets a real session and can be upgraded to a permanent account at any point.

## Enable

```ts
// convex/auth.ts
import { components } from "./_generated/api";
import { convexAuth } from "@vortex-api/convex-auth/convex";

export const auth = convexAuth({
  component: components.convexAuth,
  anonymous: {
    emailDomain: "guest.yourapp.com",
    generateName: () => `Guest ${Math.random().toString(36).slice(2, 10)}`,
    onLinkAccount: async ({ anonymousUser, newUser }, ctx) => {
      // migrate domain data from the anonymous user to the linked user
    },
  },
});
```

| Option          | Description                                                                         |
| --------------- | ----------------------------------------------------------------------------------- |
| `emailDomain`   | Synthetic email domain for the anonymous user. Defaults to `convex-auth.anonymous`. |
| `generateName`  | Optional function returning a display name. Falls back to `Guest <shortId>`.        |
| `onLinkAccount` | Optional callback for data migration during account linking.                        |

## Sign in anonymously

```tsx
import { authClient } from "@vortex-api/convex-auth/react";

const result = await authClient.signIn.anonymous();
```

The user is now signed in and `result.data.user.isAnonymous` is `true`.

## Link to a permanent account

```tsx
const result = await authClient.linkAccount({
  email: "shlomo@example.com",
  password: "hunter2!",
  name: "Shlomo",
});
```

`linkAccount` requires an active anonymous session. It creates an email/password account for the same user, flips `isAnonymous` to `false`, mints a new session, and calls `onLinkAccount` if configured.

## Security

- Anonymous users are first-class users in the `users` table with `isAnonymous: true`.
- Synthetic emails are random and unique to prevent collisions.
- `linkAccount` rejects the request if the target email already belongs to another user.