# SIP transfer (/en/ai/studio/deploy/transfer-to-sip)

> For AI agents: see the complete documentation index at [llms.txt](/llms.txt).

Use this guide when you want outbound campaign calls to transfer from the AI agent to a human destination over SIP instead of a regular phone number.

This feature is configured in **Campaign** call settings.

## Prerequisites

* A deployed agent.
* An outbound campaign.
* A SIP transfer destination.
* If you want dynamic SIP headers, your contact CSV must contain the required columns.

## How it works

When **Transfer Call to Human** is enabled in campaign settings, the agent can escalate a live call to the transfer destination based on your transfer criteria.

You can set:

* **Transfer Type** = `SIP`
* **Transfer Destination** = SIP address
* **SIP Headers** = constant or dynamic headers sent with the transfer request

## Configure SIP transfer

1. In the navigation sidebar, select **Outbound Campaigns**.
2. Create a campaign, or edit a draft campaign.
3. In **Call Settings**, enable **Transfer to Human**.
   ![Transfer to human](https://assets-docs.agora.io/images/console/campaign-transfer-call.png)
4. Set **Transfer Type** to **SIP**.
5. Enter the **Transfer Destination**.
6. Enter **Transfer Criteria** to describe when the agent should transfer the call. For example:

   ```
   Transfer the call when the user explicitly asks for a human agent, or when the request requires account actions that the agent cannot complete.
   ```

## SIP destination formats

Use one of the following SIP destination formats:

* `sip:031122@112.13.168.197:5060`
* `sip:112.13.168.197:5060`
* `sip:user@domain.com:5060`

A value without the `sip:` prefix is also accepted in the UI, but the stored transfer target is normalized as a SIP address.

## Add SIP headers

Use **SIP Headers** when the downstream SIP system expects extra metadata.

Each header has:

* **Name**
* **Type**: `Constant` or `Dynamic`
* **Value**

Header names are normalized with the `sip_h_` prefix when sent.

### Constant headers

Use constant headers when every transfer should send the same value. For example:

```
Name: queue
Type: Constant
Value: support-l2
```

### Dynamic headers

Use dynamic headers when the value should come from a campaign CSV row.

Dynamic values must contain at least one CSV column wrapped in double curly braces. For example:

```
{{first_name}}
vip-{{account_tier}}
{{case_id}}-{{region}}
```

<CalloutContainer type="info">
  <CalloutTitle>
    Note
  </CalloutTitle>

  <CalloutDescription>
    * Variable names are case-sensitive.
    * Each variable must match an uploaded CSV column name exactly.
    * If the dynamic value is missing or invalid for a contact, that header is omitted from the transfer request.
  </CalloutDescription>
</CalloutContainer>

## Prepare CSV data for dynamic headers

To use dynamic headers, add matching columns to your contact list. For example:

```
phone_number,first_name,account_tier,case_id,region
+19168888860,John,gold,C-1024,us-west
```

Then configure headers as follows:

* `customer_name` → `{{first_name}}`
* `priority` → `{{account_tier}}`
* `case_context` → `{{case_id}}-{{region}}`

## Test checklist

Before you launch a campaign, verify:

* The SIP destination is valid.
* The transfer criteria is clear and specific.
* Dynamic header variables match CSV columns exactly.
* A sample transfer reaches the expected SIP system.
* The receiving system can read the custom SIP headers.

## Troubleshooting

| Issue                              | Solution                                                                              |
| ---------------------------------- | ------------------------------------------------------------------------------------- |
| Transfer destination rejected      | Check the SIP address format and port.                                                |
| Header missing on transferred call | Check the header type, CSV column name, and whether a value exists for that contact.  |
| Transfer never happens             | Tighten the transfer criteria in call settings and the agent prompt.                  |
| Call transfers to the wrong place  | Recheck the destination field and whether you selected **SIP** instead of **Number**. |

## Next steps

* [Set up a campaign](campaign): Build an outbound call flow
* [Set up SIP trunk](sip-trunk): Prepare telephony for outbound calling
* [Agent analytics](../observe/analytics): Monitor transfer outcomes after launch