[Home](./index.md) > [sip.js](./sip.js.md) > [Transaction](./sip.js.transaction.md) > [send](./sip.js.transaction.send.md) ## Transaction.send() method Pass message to transport for transmission. If transport fails, the transaction user is notified by callback to onTransportError(). Signature: ```typescript protected send(message: string): Promise; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | message | string | | Returns: `Promise` Rejects with `TransportError` if transport fails.