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

# Session Continuation

> Allow agent to continue past conversations with users

Millis AI’s Session Continuation feature enables agents to leverage previous interaction data, allowing users to continue conversations seamlessly from prior sessions. By passing a `session_id`, agents can access past context, enhancing engagement and providing a personalized experience for users.

***

## Important Note on Data Opt-Out

**Warning**: Session Continuation is only available if **Data Opt-Out is disabled**.
When Data Opt-Out is enabled, Millis does not retain call history, so agent can't retrieve data from previous sessions. Ensure that Data Opt-Out is disabled if you require session continuation for your users.

***

## How to Pass `session_id` for Session Continuation

### 1. **Web SDK Integration**

To enable session continuation using the Millis Web SDK, use the `msClient.start` method:

```javascript theme={null}
msClient.start({
  agent: {
    agent_id: agentId
  },
  session_continuation: {
    session_id: "<previous session id>"
  }
});
```

<Tip>
  Make sure you upgrade your web sdk to v1.0.15 to have this option.
</Tip>

***

### 2. **Native Integration via WebSocket**

To continue a session via WebSocket, include the `session_id` in the `initiate` event:

```json theme={null}
{
  "method": "initiate",
  "data": {
    "agent": {
      "agent_id": "your_agent_id",
      // or for dynamic configuration
      "agent_config": "<config>"
    },
    "public_key": "your_public_key",
    "metadata": {
      "key": "value"
    },
    "include_metadata_in_prompt": true,
    "session_continuation": {
      "session_id": "<previous session id>"
    }
  }
}
```

***

### 3. **Outbound Call API Integration**

For outbound calls, the `session_id` is included in the request body when calling the `start_outbound_call` API.

#### Example Request

```json theme={null}
{
  "from_phone": "your_agent_phone_number",
  "to_phone": "receiver_phone_number",
  "metadata": {
    "key": "value"
  },
  "include_metadata_in_prompt": true,
  "session_continuation": {
    "session_id": "<previous session id>"
  }
}
```

***

## Example Scenarios

1. **Follow-Up Customer Support Calls**: A returning customer can pick up from a previous conversation by including the `session_id`, reducing the need to re-explain their issue.
2. **Ongoing Campaigns**: In multi-stage campaigns, `session_id` helps track each caller's journey, creating a more cohesive experience.
3. **Consultations**: Advisors can use session continuation to reference past discussions, fostering a more personalized relationship.

***

## Future Enhancements

* **User Identification:** Upcoming features will allow sessions to continue based on `user_id`, `phone`, or similar identifiers, adding memory across sessions without requiring a `session_id`.