---
title: User identification
description: Create Organization-scoped identities and aliases.
sidebar:
  order: 3
---

Identities belong to the Organization, not to a single Project. Use
your own stable user identifier and optional aliases:

```typescript
await client.identify({
  user_id: 'user_123',
  properties: {
    email: 'john@example.com',
    plan: 'pro',
  },
  aliases: ['john@example.com'],
});
```

Identifying the same `user_id` again merges the new `properties` into the
stored ones: new values replace old ones, and keys you leave out are kept. An
alias moves to the identity that claimed it most recently. The response lists
the aliases this call newly claimed.

An event can use the canonical identifier or an alias in `userId`. To erase a
user, call `DELETE /v1/identities/{user_id}` with the canonical identifier (see
[Erasing a user](/api#erasing-a-user)).