The Phone API

Introduction

The Phone API provides allows your extensions to listen in to the event generated by the phone when the user places and receives calls.

The Phone API will include functions to control the phone in a future API version.

Connecting to the Phone API

The extension API is available at:

window.voxtopAPI.phone

Phone API - Functions

At the moment the phone API does not provide any functions for controlling the phone.

Phone API - Events

Subscribing

As with all of the voxtopAPI events you subscribe using the onEvent function and pass a callback function to process messages.

	const unsubscribePhoneEvents = window.voxtopAPI.phone.onEvent(callback)

Unsubscribing

To unsubscribe from receiving events, simply run the function return from the onEvent function call.

unsubscribePhoneEvents();

Example Usage

	const processMessages = (event) => {
		console.log('Received phone event:', event)
	}

	const unsubscribePhoneEvents = window.voxtopAPI.phone.onEvent(processMessages)

---

Phone Event Messages

The following events describe phone connection, registration, and call lifecycle activity.

createdAt is formatted as an ISO 8601 UTC timestamp.

Required is based on the provided examples. Fields marked Conditional appear only for some call directions or event scenarios.

The following eventType values are emitted from the phone.

Event Type	Purpose
phone.state.connected	Emitted when the phone connects to the i164 network
phone.state.registered	Emitted when the phone registers with the i164 network
phone.call.created	Emitted when the phone makes or receives a new call
phone.call.progress	Emitted when a call is ringing and awaiting answer.
phone.call.accepted	Emitted when a call is answered.
phone.call.confirmed	Emitted when a call is answered and ready.
phone.call.hanging-up	Emitted when a call is in the process of being hung-up.
phone.call.ended	Emitted when a call has ended
phone.call.hold	Emitted when a call is put on hold
phone.call.unhold	Emitted when a call is taken off hold
phone.call.muted	Emitted when a call is muted
phone.call.unmuted	Emitted when a call is unmuted
phone.call.blindTransfer.started	Emitted when a blind transfer has been started for an active call
phone.call.blindTransfer.succeeded	Emitted when a blind transfer has completed successfully.

---

phone.state.connected

Emitted when the phone connection is established.

{
  "eventId": "719fc228-b7fc-45f4-ae63-6188b6dc6f6a",
  "createdAt": "2026-07-03T14:30:54.446Z",
  "eventType": "phone.state.connected",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea"
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.state.connected.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.

---

phone.state.registered

Emitted when the phone device has successfully registered.

{
  "eventId": "835fb0ac-7deb-4fe2-9c4c-5431db052dc3",
  "createdAt": "2026-07-03T14:30:54.525Z",
  "eventType": "phone.state.registered",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea"
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.state.registered.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.

---

phone.call.created

Emitted when a new phone call is created.

{
  "eventId": "80f1f421-16ef-457d-b650-da9f0725e482",
  "createdAt": "2026-07-03T14:34:47.525Z",
  "eventType": "phone.call.created",
  "direction": "incoming",
  "callRef": "5c0481f8-538e-4ab8-9025-4b28dccba607",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "phoneServiceUUID": "3e560df5-3792-4206-960d-f53792020693",
  "voxletInstanceUUID": "c5e8e1f6-50c5-48c0-a8e1-f650c5a8c08f",
  "state": "new",
  "onHold": false,
  "stt": {
    "local": false,
    "remote": false
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "07XXXXXXXX",
  "remoteDisplayName": "Max"
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.created.
direction	string	Yes	Direction of the call. Observed values are incoming and outgoing.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
phoneServiceUUID	string	Conditional	Unique identifier for the phone service. Present in the provided incoming call examples.
voxletInstanceUUID	string	Conditional	Unique identifier for the Voxlet instance. Present in the provided incoming call examples.
state	string	Yes	Current call state. Observed values for this event are new and dialled.
onHold	boolean	Yes	Indicates whether the call is currently on hold.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

---

phone.call.progress

Emitted when a call is progressing, such as when the remote side is ringing.

{
  "eventId": "c7158bc6-f91a-4839-9e46-5386c592f581",
  "createdAt": "2026-07-03T14:31:23.726Z",
  "eventType": "phone.call.progress",
  "direction": "outgoing",
  "callRef": "4378a4ff-2ff9-49a0-a8ad-e9b64a0394d9",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "state": "progress",
  "onHold": false,
  "stt": {
    "local": false,
    "remote": false
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "123",
  "remoteDisplayName": null,
  "data": {
    "originator": "remote",
    "statusCode": 180,
    "reasonPhrase": "Ringing"
  }
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.progress.
direction	string	Yes	Direction of the call. Observed values are incoming and outgoing.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
phoneServiceUUID	string	Conditional	Unique identifier for the phone service. Present in the provided incoming call examples.
voxletInstanceUUID	string	Conditional	Unique identifier for the Voxlet instance. Present in the provided incoming call examples.
state	string	Yes	Current call state. For this event, the observed value is progress.
onHold	boolean	Yes	Indicates whether the call is currently on hold.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.
data	object	Conditional	Additional progress information, such as SIP-style status details.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

data object

Property	Type	Required	Description
data.originator	string	Yes	Party that originated the progress update. Observed value is remote.
data.statusCode	number	Yes	Status code associated with the progress update. Example value is 180.
data.reasonPhrase	string	Yes	Human-readable reason phrase associated with the progress update. Example value is Ringing.

---

phone.call.accepted

Emitted when a call has been accepted.

{
  "eventId": "35873b1a-38b5-44df-ad5b-3438ad43c261",
  "createdAt": "2026-07-03T14:34:50.954Z",
  "eventType": "phone.call.accepted",
  "direction": "incoming",
  "callRef": "5c0481f8-538e-4ab8-9025-4b28dccba607",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "phoneServiceUUID": "3e560df5-3792-4206-960d-f53792020693",
  "voxletInstanceUUID": "c5e8e1f6-50c5-48c0-a8e1-f650c5a8c08f",
  "state": "accepted",
  "onHold": false,
  "stt": {
    "local": false,
    "remote": false
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "07XXXXXXXX",
  "remoteDisplayName": "Max"
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.accepted.
direction	string	Yes	Direction of the call. Observed values are incoming and outgoing.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
phoneServiceUUID	string	Conditional	Unique identifier for the phone service. Present in the provided incoming call examples.
voxletInstanceUUID	string	Conditional	Unique identifier for the Voxlet instance. Present in the provided incoming call examples.
state	string	Yes	Current call state. For this event, the observed value is accepted.
onHold	boolean	Yes	Indicates whether the call is currently on hold.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

---

phone.call.confirmed

Emitted when a call has been confirmed and is active.

{
  "eventId": "eb675ff3-e330-4731-af09-150614a21d7f",
  "createdAt": "2026-07-03T14:34:50.988Z",
  "eventType": "phone.call.confirmed",
  "direction": "incoming",
  "callRef": "5c0481f8-538e-4ab8-9025-4b28dccba607",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "phoneServiceUUID": "3e560df5-3792-4206-960d-f53792020693",
  "voxletInstanceUUID": "c5e8e1f6-50c5-48c0-a8e1-f650c5a8c08f",
  "state": "confirmed",
  "onHold": false,
  "stt": {
    "local": false,
    "remote": false
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "07XXXXXXXX",
  "remoteDisplayName": "Max"
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.confirmed.
direction	string	Yes	Direction of the call. Observed values are incoming and outgoing.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
phoneServiceUUID	string	Conditional	Unique identifier for the phone service. Present in the provided incoming call examples.
voxletInstanceUUID	string	Conditional	Unique identifier for the Voxlet instance. Present in the provided incoming call examples.
state	string	Yes	Current call state. For this event, the observed value is confirmed.
onHold	boolean	Yes	Indicates whether the call is currently on hold.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

---

phone.call.hanging-up

Emitted when a call is in the process of being hung up.

{
  "eventId": "14ef0d68-1181-46a3-a116-9a7967dfbae5",
  "createdAt": "2026-07-03T14:34:56.164Z",
  "eventType": "phone.call.hanging-up",
  "direction": "incoming",
  "callRef": "5c0481f8-538e-4ab8-9025-4b28dccba607",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "phoneServiceUUID": "3e560df5-3792-4206-960d-f53792020693",
  "voxletInstanceUUID": "c5e8e1f6-50c5-48c0-a8e1-f650c5a8c08f",
  "state": "confirmed",
  "onHold": false,
  "stt": {
    "local": true,
    "remote": true
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "07XXXXXXXX",
  "remoteDisplayName": "Max"
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.hanging-up.
direction	string	Yes	Direction of the call. Observed value is incoming.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
phoneServiceUUID	string	Yes	Unique identifier for the phone service.
voxletInstanceUUID	string	Yes	Unique identifier for the Voxlet instance.
state	string	Yes	Current call state at the time the hang-up is initiated. Observed value is confirmed.
onHold	boolean	Yes	Indicates whether the call is currently on hold.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

---

phone.call.ended

Emitted when a call has ended.

{
  "eventId": "4fd1bb90-9028-4a68-9eab-dfcb79a906d9",
  "createdAt": "2026-07-03T14:34:56.171Z",
  "eventType": "phone.call.ended",
  "direction": "incoming",
  "callRef": "5c0481f8-538e-4ab8-9025-4b28dccba607",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "phoneServiceUUID": "3e560df5-3792-4206-960d-f53792020693",
  "voxletInstanceUUID": "c5e8e1f6-50c5-48c0-a8e1-f650c5a8c08f",
  "state": "ended",
  "onHold": false,
  "stt": {
    "local": true,
    "remote": true
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "07XXXXXXXX",
  "remoteDisplayName": "Max",
  "data": {
    "originator": "local",
    "cause": "Terminated",
    "statusCode": null,
    "reasonPhrase": null
  }
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.ended.
direction	string	Yes	Direction of the call. Observed values are incoming and outgoing.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
phoneServiceUUID	string	Conditional	Unique identifier for the phone service. Present in the provided incoming call examples.
voxletInstanceUUID	string	Conditional	Unique identifier for the Voxlet instance. Present in the provided incoming call examples.
state	string	Yes	Current call state. For this event, the observed value is ended.
onHold	boolean	Yes	Indicates whether the call is currently on hold.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.
data	object	Yes	Additional information about why the call ended.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

data object

Property	Type	Required	Description
data.originator	string	Yes	Party that originated the call termination. Observed values are local and remote.
data.cause	string	Yes	Cause of the call termination. Example value is Terminated.
data.statusCode	number/null	Conditional	Status code associated with the call termination, or null when unavailable.
data.reasonPhrase	string/null	Conditional	Human-readable reason phrase associated with the call termination, or null when unavailable.

---

phone.call.hold

Emitted when a call is placed on hold.

{
  "eventId": "e98700cb-ffe1-4ed1-a617-389c11307497",
  "createdAt": "2026-07-03T14:42:35.746Z",
  "eventType": "phone.call.hold",
  "direction": "incoming",
  "callRef": "e06ce829-ce09-4ec1-850f-95081216078c",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "phoneServiceUUID": "3e560df5-3792-4206-960d-f53792020693",
  "voxletInstanceUUID": "c5e8e1f6-50c5-48c0-a8e1-f650c5a8c08f",
  "state": "confirmed",
  "onHold": true,
  "stt": {
    "local": true,
    "remote": true
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "07XXXXXXXX",
  "remoteDisplayName": "Max"
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.hold.
direction	string	Yes	Direction of the call. Observed value is incoming.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
phoneServiceUUID	string	Yes	Unique identifier for the phone service.
voxletInstanceUUID	string	Yes	Unique identifier for the Voxlet instance.
state	string	Yes	Current call state. For this event, the observed value is confirmed.
onHold	boolean	Yes	Indicates whether the call is currently on hold. For this event, the value is true.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

---

phone.call.unhold

Emitted when a call is taken off hold.

{
  "eventId": "891fb14f-1cb2-4856-b568-0b50f5d41a9c",
  "createdAt": "2026-07-03T14:42:40.213Z",
  "eventType": "phone.call.unhold",
  "direction": "incoming",
  "callRef": "e06ce829-ce09-4ec1-850f-95081216078c",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "phoneServiceUUID": "3e560df5-3792-4206-960d-f53792020693",
  "voxletInstanceUUID": "c5e8e1f6-50c5-48c0-a8e1-f650c5a8c08f",
  "state": "confirmed",
  "onHold": false,
  "stt": {
    "local": true,
    "remote": true
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "07XXXXXXXX",
  "remoteDisplayName": "Max"
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.unhold.
direction	string	Yes	Direction of the call. Observed value is incoming.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
phoneServiceUUID	string	Yes	Unique identifier for the phone service.
voxletInstanceUUID	string	Yes	Unique identifier for the Voxlet instance.
state	string	Yes	Current call state. For this event, the observed value is confirmed.
onHold	boolean	Yes	Indicates whether the call is currently on hold. For this event, the value is false.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

---

phone.call.muted

Emitted when the local call audio is muted.

{
  "eventId": "db308856-3dd9-4840-a738-2ccca828c8ea",
  "createdAt": "2026-07-03T14:51:21.344Z",
  "eventType": "phone.call.muted",
  "direction": "outgoing",
  "callRef": "aa3382b8-db67-413f-bfbe-bbf03959347c",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "state": "confirmed",
  "onHold": false,
  "stt": {
    "local": true,
    "remote": true
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "123",
  "remoteDisplayName": null
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.muted.
direction	string	Yes	Direction of the call. Observed value is outgoing.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
state	string	Yes	Current call state. For this event, the observed value is confirmed.
onHold	boolean	Yes	Indicates whether the call is currently on hold.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

---

phone.call.unmuted

Emitted when the local call audio is unmuted.

{
  "eventId": "db308856-3dd9-4840-a738-2ccca828c8ea",
  "createdAt": "2026-07-03T14:51:21.344Z",
  "eventType": "phone.call.unmuted",
  "direction": "outgoing",
  "callRef": "aa3382b8-db67-413f-bfbe-bbf03959347c",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "state": "confirmed",
  "onHold": false,
  "stt": {
    "local": true,
    "remote": true
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "123",
  "remoteDisplayName": null
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.unmuted.
direction	string	Yes	Direction of the call. Observed value is outgoing.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
state	string	Yes	Current call state. For this event, the observed value is confirmed.
onHold	boolean	Yes	Indicates whether the call is currently on hold.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

---

phone.call.blindTransfer.started

Emitted when a blind transfer has been started for an active call.

{
  "eventId": "8bb8cce7-e3de-4b44-af91-3c7259c1f885",
  "createdAt": "2026-07-03T15:21:55.150Z",
  "eventType": "phone.call.blindTransfer.started",
  "direction": "incoming",
  "callRef": "e257a740-a93f-44f7-b727-e89e8e6f71bb",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "phoneServiceUUID": "3e560df5-3792-4206-960d-f53792020693",
  "voxletInstanceUUID": "c5e8e1f6-50c5-48c0-a8e1-f650c5a8c08f",
  "state": "confirmed",
  "onHold": true,
  "stt": {
    "local": true,
    "remote": true
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "0203XXXXXXX",
  "remoteDisplayName": "Max",
  "data": {
    "targetNumber": "07XXXXXXXX"
  }
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.blindTransfer.started.
direction	string	Yes	Direction of the call. Observed value is incoming.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
phoneServiceUUID	string	Yes	Unique identifier for the phone service.
voxletInstanceUUID	string	Yes	Unique identifier for the Voxlet instance.
state	string	Yes	Current call state at the time the blind transfer is started. Observed value is confirmed.
onHold	boolean	Yes	Indicates whether the call is currently on hold. For this event, the value is true.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.
data	object	Yes	Additional blind transfer information.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

data object

Property	Type	Required	Description
data.targetNumber	string	Yes	Number that the call is being transferred to.

---

phone.call.blindTransfer.succeeded

Emitted when a blind transfer has completed successfully.

{
  "eventId": "c84db670-f5de-4ccc-9625-916af60d0820",
  "createdAt": "2026-07-03T15:21:55.211Z",
  "eventType": "phone.call.blindTransfer.succeeded",
  "direction": "incoming",
  "callRef": "e257a740-a93f-44f7-b727-e89e8e6f71bb",
  "connectionId": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "deviceRegistrationUUID": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "virtualDeviceRegistrationUUID": "e4971753-daca-4c9f-9717-53daca1c9f51",
  "phoneServiceUUID": "3e560df5-3792-4206-960d-f53792020693",
  "voxletInstanceUUID": "c5e8e1f6-50c5-48c0-a8e1-f650c5a8c08f",
  "state": "confirmed",
  "onHold": true,
  "stt": {
    "local": true,
    "remote": true
  },
  "localNumber": "8f1fa31a-2389-4412-9fa3-1a23892412ea",
  "localDisplayName": "Voxtop Desktop",
  "remoteNumber": "0203XXXXXXX",
  "remoteDisplayName": "Max",
  "data": {
    "targetNumber": "07XXXXXXXX",
    "statusCode": 202
  }
}

Properties

Property	Type	Required	Description
eventId	string	Yes	Unique identifier for this event message.
createdAt	string	Yes	Time the event occurred, formatted as an ISO 8601 UTC timestamp.
eventType	string	Yes	Name of the event. For this message, the value is phone.call.blindTransfer.succeeded.
direction	string	Yes	Direction of the call. Observed value is incoming.
callRef	string	Yes	Unique reference for the call. This value can be used to correlate events for the same call.
connectionId	string	Yes	Unique identifier for the phone connection.
deviceRegistrationUUID	string	Yes	Unique identifier for the registered phone device.
virtualDeviceRegistrationUUID	string	Yes	Unique identifier for the virtual device registration associated with the call.
phoneServiceUUID	string	Yes	Unique identifier for the phone service.
voxletInstanceUUID	string	Yes	Unique identifier for the Voxlet instance.
state	string	Yes	Current call state at the time the blind transfer succeeds. Observed value is confirmed.
onHold	boolean	Yes	Indicates whether the call is currently on hold. For this event, the value is true.
stt	object	Yes	Speech-to-text status for the local and remote parties.
localNumber	string	Yes	Number or identifier for the local party.
localDisplayName	string	Yes	Display name for the local party.
remoteNumber	string	Yes	Number or identifier for the remote party.
remoteDisplayName	string/null	Yes	Display name for the remote party, or null when unavailable.
data	object	Yes	Additional blind transfer result information.

stt object

Property	Type	Required	Description
stt.local	boolean	Yes	Indicates whether speech-to-text is enabled or active for the local party.
stt.remote	boolean	Yes	Indicates whether speech-to-text is enabled or active for the remote party.

data object

Property	Type	Required	Description
data.targetNumber	string	Yes	Number that the call was transferred to.
data.statusCode	number	Yes	Status code returned for the blind transfer request. Example value is 202.

phone.call.blindTransfer.failed

Emitted when a blind transfer has failed.