***

title: sipRefer
slug: /reference/typescript/agents/function-result/sip-refer
description: Send a SIP REFER message to transfer the call in a SIP environment.
max-toc-depth: 3
---------------------

For a complete index of all SignalWire documentation pages, fetch https://signalwire.com/docs/llms.txt

[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).
</Tip>

## **Parameters**

<ParamField path="toUri" type="string" required={true} toc={true}>
  SIP URI to send the REFER to (e.g., `"sip:1001@pbx.example.com"`).
</ParamField>

## **Returns**

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

## **Example**

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

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