[Home](./index.md) > [sip.js](./sip.js.md) > [UserAgentCoreDelegate](./sip.js.useragentcoredelegate.md) > [onMessage](./sip.js.useragentcoredelegate.onmessage.md) ## UserAgentCoreDelegate.onMessage() method Receive MESSAGE request. Signature: ```typescript onMessage?(request: IncomingMessageRequest): void; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | request | IncomingMessageRequest | Incoming MESSAGE request. | Returns: `void`