> ## Documentation Index
> Fetch the complete documentation index at: https://docs.solute.so/llms.txt
> Use this file to discover all available pages before exploring further.

# User Identification

> Identify users and manage sessions

## User Identification

The Solute SDK automatically manages user identification and sessions. Learn how to identify users and work with sessions.

## Anonymous vs Identified Users

The SDK supports two types of user identification:

* **Anonymous users**: Automatically assigned an anonymous ID. Used before user login.
* **Identified users**: Assigned a user ID when you call `identify()`. Used after user login.

## Identify Users

Identify a user when they log in or sign up:

```typescript theme={null}
import { SoluteClient } from '@solute-ai/sdk';

const solute = new SoluteClient({
  apiKey: 'your_api_key',
  host: 'https://api.solute.dev',
});

// Identify user with traits
solute.identify('user_123', {
  email: 'user@example.com',
  name: 'John Doe',
  plan: 'premium',
  created_at: '2025-01-01T00:00:00Z',
});
```

<Tip>
  Call `identify()` as soon as you know the user's ID. All subsequent events will be associated with this user.
</Tip>

## Get User Information

```typescript theme={null}
// Get current user ID
const userId = solute.getUserId(); // 'user_123' or undefined

// Get anonymous ID (always available)
const anonymousId = solute.getAnonymousId(); // 'anon_456'

// Get session ID
const sessionId = solute.getSessionId(); // 'session_789'
```

## Alias Anonymous to Identified

When a user signs up, merge their anonymous identity with their new user ID:

```typescript theme={null}
// Before signup (anonymous)
const anonymousId = solute.getAnonymousId(); // 'anon_456'

// User signs up
solute.identify('user_123', {
  email: 'user@example.com',
});

// Alias the anonymous ID with the user ID
solute.alias('user_123', anonymousId);
```

This ensures all events from before signup are associated with the user.

## Reset User

Reset user identity on logout:

```typescript theme={null}
// Reset user and start a new session
solute.reset();
```

After `reset()`, the SDK will:

* Clear the user ID
* Generate a new anonymous ID
* Start a new session
* Clear user traits

## Session Management

Sessions are automatically managed by the SDK:

* **Session creation**: A new session starts when the SDK initializes
* **Session timeout**: Sessions expire after 30 minutes of inactivity (configurable)
* **Session ID**: Each session has a unique ID that's included in all events

### Configure Session Timeout

```typescript theme={null}
const solute = new SoluteClient({
  apiKey: 'your_api_key',
  sessionTimeout: 60 * 60 * 1000, // 1 hour (in milliseconds)
});
```

## User Traits

Store user properties as traits:

```typescript theme={null}
// Set initial traits
solute.identify('user_123', {
  email: 'user@example.com',
  name: 'John Doe',
  plan: 'premium',
});

// Update traits later
solute.identify('user_123', {
  plan: 'enterprise', // Update plan
  company: 'Acme Corp', // Add new trait
});
```

Traits are included in all subsequent events and can be used for feature flag targeting.

## Next.js Integration

### Client Components

```tsx theme={null}
'use client';

import { useIdentify, useUser } from '@solute-ai/sdk/nextjs';

export function UserProfile() {
  const identify = useIdentify();
  const { userId, anonymousId, sessionId } = useUser();

  const handleLogin = async (userData: { id: string; email: string }) => {
    // Identify user after login
    identify(userData.id, {
      email: userData.email,
    });
  };

  return (
    <div>
      {userId ? (
        <p>Logged in as: {userId}</p>
      ) : (
        <p>Anonymous ID: {anonymousId}</p>
      )}
      <p>Session: {sessionId}</p>
    </div>
  );
}
```

### Server Components

```tsx theme={null}
// app/profile/page.tsx
import { getUserIdFromCookies, getAnonymousIdFromCookies } from '@solute-ai/sdk/nextjs';

export default async function ProfilePage() {
  const userId = await getUserIdFromCookies();
  const anonymousId = await getAnonymousIdFromCookies();

  return (
    <div>
      {userId ? (
        <p>User ID: {userId}</p>
      ) : (
        <p>Anonymous ID: {anonymousId}</p>
      )}
    </div>
  );
}
```

## Best Practices

<AccordionGroup>
  <Accordion title="Identify early">
    Call `identify()` as soon as you know the user's ID to associate all events with the user.
  </Accordion>

  <Accordion title="Alias on signup">
    Always alias the anonymous ID with the user ID when a user signs up to preserve event history.
  </Accordion>

  <Accordion title="Reset on logout">
    Call `reset()` when users log out to start a fresh session for the next user.
  </Accordion>

  <Accordion title="Update traits regularly">
    Keep user traits up to date by calling `identify()` when user properties change.
  </Accordion>
</AccordionGroup>

## Next Steps

<CardGroup cols={2}>
  <Card title="Event Tracking" icon="chart-line" href="/guides/event-tracking">
    Learn about tracking events
  </Card>

  <Card title="Next.js Integration" icon="react" href="/guides/nextjs-integration">
    Deep dive into Next.js integration
  </Card>
</CardGroup>