Alexa.InputController Interface
Implement the Alexa.InputController capability interface in your smart home skill so that users can change the input of an entertainment device.
For the list of locales that are supported for the InputController interface, see List of Capability Interfaces and Supported Locales.
Utterances
When you use the Alexa.InputController interface, the voice interaction model is already built for you. The following examples show some user utterances:
Alexa, change the input to DVD on the Living Room TV.
After the user says one of these utterances, Alexa sends a corresponding directive to your skill.
Properties
The input property
The Alexa.InputController interface uses the input property as the primary property. The property values are strings.
Input property example
{
"input": "HDMI 1",
}
Input values
The following are the valid input values:
AUX 1, AUX 2, AUX 3, AUX 4, AUX 5, AUX 6, AUX 7, BLURAY, CABLE, CD, COAX 1, COAX 2, COMPOSITE 1, DVD, GAME, HD RADIO, HDMI 1, HDMI 2, HDMI 3, HDMI 4, HDMI 5, HDMI 6, HDMI 7, HDMI 8, HDMI 9, HDMI 10, HDMI ARC, INPUT 1, INPUT 2, INPUT 3, INPUT 4, INPUT 5, INPUT 6, INPUT 7, INPUT 8, INPUT 9, INPUT 10, IPOD, LINE 1, LINE 2, LINE 3, LINE 4, LINE 5, LINE 6, LINE 7, MEDIA PLAYER, OPTICAL 1, OPTICAL 2, PHONO, PLAYSTATION, PLAYSTATION 3, PLAYSTATION 4, SATELLITE, SMARTCAST, TUNER, TV, USB DAC, VIDEO 1, VIDEO 2, VIDEO 3, XBOX
Discovery
You describe endpoints that support Alexa.InputController using the standard discovery mechanism described in Alexa.Discovery.
Set retrievable to true for the properties that you report when Alexa sends your skill a state report request.
Set proactivelyReported to true for the properties that you proactively report to Alexa in a change report.
Use TV, STREAMING_DEVICE, GAME_CONSOLE, or other appropriate display category. For the full list of display categories, see display categories.
In addition to the usual discovery response fields, for InputController, include the following field.
| Field | Description | Type |
|---|---|---|
inputs |
An array of objects that each contain a name field. Each object contains the name of a valid input value that your device supports. Each name must be unique across inputs for this device. |
Array |
Discover response example
The following example shows a Discover.Response message for a television that supports the Alexa.InputController and Alexa.PowerController interfaces. For the full list of recommended interfaces for a television, see Smart Home Skill Device Templates.
{
"event": {
"header": {
"namespace": "Alexa.Discovery",
"name": "Discover.Response",
"payloadVersion": "3",
"messageId": "<message id>"
},
"payload": {
"endpoints": [
{
"endpointId": "<unique ID of the endpoint>",
"manufacturerName": "<the manufacturer name of the endpoint>",
"description": "Smart Television by Television Maker",
"friendlyName": "Living Room TV",
"displayCategories": ["TV"],
"cookie": {},
"capabilities": [
{
"type": "AlexaInterface",
"interface": "Alexa.InputController",
"version": "3",
"properties": {
"supported": [
{
"name": "input"
}
],
"proactivelyReported": true,
"retrievable": true
},
"inputs": [
{
"name": "HDMI 1"
},
{
"name": "HDMI 2"
}
]
},
{
"type": "AlexaInterface",
"interface": "Alexa.PowerController",
"version": "3",
"properties": {
"supported": [
{
"name": "powerState"
}
],
"proactivelyReported": true,
"retrievable": true
}
},
{
"type": "AlexaInterface",
"interface": "Alexa",
"version": "3"
}
]
}
]
}
}
}
AddOrUpdateReport
You must proactively send an Alexa.Discovery.AddOrUpdateReport message if the feature support of your endpoint changes after your initial discovery response. For example, if the inputs that your device supports changes, notify Alexa by sending an AddOrUpdateReport message. For more information, see AddOrUpdateReport.
AddOrUpdateReport event example
{
"event": {
"header": {
"namespace": "Alexa.Discovery",
"name": "AddOrUpdateReport",
"payloadVersion": "3",
"messageId": "<message id>"
},
"payload": {
"endpoints": [
{
"endpointId": "<unique ID of the endpoint>",
"manufacturerName": "<the manufacturer name of the endpoint>",
"description": "Smart Television by Television Maker",
"friendlyName": "Living Room TV",
"displayCategories": ["TV"],
"cookie": {},
"capabilities": [
{
"type": "AlexaInterface",
"interface": "Alexa.InputController",
"version": "3",
"properties": {
"supported": [
{
"name": "input"
}
],
"proactivelyReported": true,
"retrievable": true
},
"inputs": [
{
"name": "HDMI 1"
},
{
"name": "HDMI 2"
},
{
"name": "AUX 1"
},
{
"name": "AUX 2"
}
]
},
{
"type": "AlexaInterface",
"interface": "Alexa.PowerController",
"version": "3",
"properties": {
"supported": [
{
"name": "powerState"
}
],
"proactivelyReported": true,
"retrievable": true
}
},
{
"type": "AlexaInterface",
"interface": "Alexa",
"version": "3"
}
]
}
]
}
}
}
Directives
SelectInput directive
Support the SelectInput directive so that users can change the input on a device.
The following example shows a user utterance:
Alexa, change the input to HDMI 1 on the Living Room TV.
SelectInput directive payload details
| Field | Description | Type |
|---|---|---|
input |
The input to change the device to. | An input property. |
SelectInput directive example
{
"directive": {
"header": {
"namespace": "Alexa.InputController",
"name": "SelectInput",
"messageId": "<message id>",
"correlationToken": "<an opaque correlation token>",
"payloadVersion": "3"
},
"endpoint": {
"scope": {
"type": "BearerToken",
"token": "<an OAuth2 bearer token>"
},
"endpointId": "<endpoint id>",
"cookie": {}
},
"payload": {
"input": "HDMI 1"
}
}
}
SelectInput response event
If you handle a SelectInput directive successfully, respond with an Alexa.Response event. In the context object, include the values of all properties that changed.
SelectInput response event example
{
"event": {
"header": {
"namespace": "Alexa",
"name": "Response",
"messageId": "<message id>",
"correlationToken": "<an opaque correlation token>",
"payloadVersion": "3"
},
"endpoint":{
"endpointId": "<endpoint id>"
},
"payload": {}
},
"context": {
"properties": [
{
"namespace": "Alexa.InputController",
"name": "input",
"value": "HDMI 1",
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 0
},
{
"namespace": "Alexa.PowerController",
"name": "powerState",
"value": "ON",
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 500
}
]
}
}
SelectInput directive error handling
If you can't handle a SelectInput directive successfully, respond with an Alexa.ErrorResponse event.
State reporting
Alexa sends a ReportState directive to request information about the state of an endpoint. When Alexa sends a ReportState directive, you send a StateReport event in response. The response contains the current state of all of the retrievable properties in the context object. You identify your retrievable properties in your discovery response. For more information about state reports, see Understand State and Change Reporting.
StateReport response event example
{
"event": {
"header": {
"namespace": "Alexa",
"name": "StateReport",
"messageId": "<message id>",
"correlationToken": "<an opaque correlation token>",
"payloadVersion": "3"
},
"endpoint": {
"scope": {
"type": "BearerToken",
"token": "<an OAuth2 bearer token>"
},
"endpointId": "<endpoint id>"
},
"payload": {}
},
"context": {
"properties": [
{
"namespace": "Alexa.InputController",
"name": "input",
"value": "HDMI 1",
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 0
},
{
"namespace": "Alexa.PowerController",
"name": "powerState",
"value": "ON",
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 500
}
]
}
}
Change reporting
You send a ChangeReport event to proactively report changes in the state of an endpoint. You identify the properties that you proactively report in your discovery response. For more information about change reports, see Understand State and Change Reporting.
ChangeReport event example
{
"event": {
"header": {
"namespace": "Alexa",
"name": "ChangeReport",
"messageId": "<message id>",
"payloadVersion": "3"
},
"endpoint": {
"scope": {
"type": "BearerToken",
"token": "<an OAuth2 bearer token>"
},
"endpointId": "<endpoint id>"
},
"payload": {
"change": {
"cause": {
"type": "VOICE_INTERACTION"
},
"properties": [
{
"namespace": "Alexa.InputController",
"name": "input",
"value": "HDMI 2",
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 0
}
]
}
}
},
"context": {
"properties": [
{
"namespace": "Alexa.PowerController",
"name": "powerState",
"value": "ON",
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 500
}
]
}
}
