[Home](./index.md) > [sip.js](./sip.js.md) > [ReferUserAgentServer](./sip.js.referuseragentserver.md) > [(constructor)](./sip.js.referuseragentserver._constructor_.md) ## ReferUserAgentServer.(constructor) REFER UAS constructor. Signature: ```typescript constructor(dialogOrCore: SessionDialog | UserAgentCore, message: IncomingRequestMessage, delegate?: IncomingRequestDelegate); ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | dialogOrCore | SessionDialog | UserAgentCore | Dialog for in dialog REFER, UserAgentCore for out of dialog REFER. | | message | IncomingRequestMessage | Incoming REFER request message. | | delegate | IncomingRequestDelegate | |