[Home](./index.md) > [sip.js](./sip.js.md) > [Publisher](./sip.js.publisher.md) > [(constructor)](./sip.js.publisher._constructor_.md) ## Publisher.(constructor) Constructs a new instance of the `Publisher` class. Signature: ```typescript constructor(userAgent: UserAgent, targetURI: URI, eventType: string, options?: PublisherOptions); ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | userAgent | UserAgent | User agent. See [UserAgent](./sip.js.useragent.md) for details. | | targetURI | URI | Request URI identifying the target of the message. | | eventType | string | The event type identifying the published document. | | options | PublisherOptions | Options bucket. See [PublisherOptions](./sip.js.publisheroptions.md) for details. |