| from | string | Yes | The calling party number |
| to | object | Yes | Destination for the call (see Target schema) |
| application_sid | string | No | The application to use to control this call. Either application_sid or call_hook is required. |
| call_hook | Webhook | No | Inline webhook config. Either application_sid or call_hook is required. |
| call_status_hook | Webhook | No | Webhook for call status events |
| answerOnBridge | boolean | No | If true, inbound leg rings until dialed number answers, then 200 OK is sent. If false, inbound is answered immediately. |
| timeout | integer | No | Seconds to wait for answer. Default: 60. |
| timeLimit | integer | No | Max length of call in seconds |
| tag | object | No | Initial customer-supplied metadata (see Graine ‘tag’ verb) |
| headers | object | No | Customer SIP headers to associate with the call |
| fromHost | string | No | Hostname for the SIP From header of the INVITE |
| sipRequestWithinDialogHook | string | No | SIP in-dialog hook for session messages |
| speech_synthesis_vendor | string | No | TTS vendor (required if application_sid not used) |
| speech_synthesis_language | string | No | TTS language (required if application_sid not used) |
| speech_synthesis_voice | string | No | TTS voice (required if application_sid not used) |
| speech_recognizer_vendor | string | No | STT vendor (required if application_sid not used) |
| speech_recognizer_language | string | No | STT language (required if application_sid not used) |
| amd | object | No | Answering machine detection config |