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# sipRefer

> Send a SIP REFER message to transfer the call in a SIP environment.

[connect]: /docs/server-sdks/reference/typescript/agents/function-result/connect

[functionresult]: /docs/server-sdks/reference/typescript/agents/function-result

Send a SIP REFER message to transfer the call in a SIP environment. This is
used for attended or blind transfers within SIP-based phone systems and PBX
deployments.

> **Tip**
>
> For standard phone-number or SIP-address transfers, use
> [`connect()`][connect]
> instead. Use `sipRefer()` when the transfer must be performed via the SIP
> REFER mechanism (e.g., transferring to a PBX extension).

## **Parameters**

**`toUri`** `string` — required

SIP URI to send the REFER to (e.g., `"sip:1001@pbx.example.com"`).

---

## **Returns**

[`FunctionResult`][functionresult] -- `this`, for chaining.

## **Example**

```typescript {4}
import { FunctionResult } from '@signalwire/sdk';

const result = new FunctionResult()
  .sipRefer('sip:support@example.com');
```

> Send a SIP REFER message to transfer the call in a SIP environment.