Alexa.PercentageController Interface 3

Implement the Alexa.PercentageController interface in your Alexa add-on so that users can control properties of devices that can be expressed as a percentage. For more details about smart home add-ons, see Connect Your Device Cloud with Smart Home Add-ons. Use this interface only if there isn’t a more specific controller interface that applies to your device. For example, if you want to handle requests specific to brightness values, implement the Alexa.BrightnessController interface instead. If you want to handle requests specific to the power level of an endpoint, such as a dimmer switch, implement the Alexa.PowerLevelController interface instead. For the list of languages that the PercentageController interface supports, see List of Alexa Interfaces and Supported Languages. For the definitions of the message properties, see Alexa Interface Message and Property Reference.

Utterances

When you use the Alexa.PercentageController interface, the voice interaction model is already built for you. After the user says one of the following utterances, Alexa sends a corresponding directive to your add-on. The following examples show user utterances:

Reportable properties

The Alexa.PercentageController interface uses the percentage property as the primary property. The property is an integer with valid values from 0 to 100 inclusive. If you use the percentage property to represent a change, valid values are from –100 to 100 inclusive.

Discovery

You describe endpoints that support Alexa.PercentageController using the standard discovery mechanism described in Alexa.Discovery. Set retrievable to true for all the interfaces and properties that you report when Alexa sends your add-on a state report request. Set proactivelyReported to true for interfaces and properties that you proactively report to Alexa in a change report. For the full list of display categories, see display categories. To let Alexa know the health of your device, also implement the Alexa.EndpointHealth interface.

Discover response example

The following example shows a Discover.Response message for a device that supports the Alexa.PercentageController interface.

{
  "event": {
    "header": {
      "namespace": "Alexa.Discovery",
      "name": "Discover.Response",
      "payloadVersion": "3",
      "messageId": "Unique identifier, preferably a version 4 UUID"
    },
    "payload": {
      "endpoints": [
        {
          "endpointId": "Unique ID of the endpoint",
          "manufacturerName": "Manufacturer of the endpoint",
          "description": "Description to be shown in the Alexa app",
          "friendlyName": "Device name, displayed in the Alexa app",
          "additionalAttributes":  {
            "manufacturer": "Manufacturer of the endpoint",
            "model" : "Model of the device",
            "customIdentifier": "Optional custom identifier for the device"
          },
          "displayCategories": ["OTHER"],
          "cookie": {},
          "capabilities": [
            {
              "type": "AlexaInterface",
              "interface": "Alexa.PercentageController",
              "version": "3",
              "properties": {
                "supported": [
                  {
                    "name": "percentage"
                  }
                ],
                "proactivelyReported": true,
                "retrievable": true
              }
            },
            {
              "type": "AlexaInterface",
              "interface": "Alexa.EndpointHealth",
              "version": "3",
              "properties": {
                "supported": [
                  {
                    "name": "connectivity"
                  }
                ],
                "proactivelyReported": true,
                "retrievable": true
              }
            },            
            {
              "type": "AlexaInterface",
              "interface": "Alexa",
              "version": "3"
            }
          ]
        }
      ]
    }
  }
}

Directives

Alexa sends the following Alexa.PercentageController interface directives to your add-on.

SetPercentage directive

Support the SetPercentage directive so that users can set the percentage value of a device setting. The following examples show user utterances:

SetPercentage directive example

{
  "directive": {
    "header": {
      "namespace": "Alexa.PercentageController",
      "name": "SetPercentage",
      "messageId": "Unique version 4 UUID",
      "correlationToken": "Opaque correlation token",
      "payloadVersion": "3"
    },
    "endpoint": {
      "scope": {
        "type": "BearerToken",
        "token": "OAuth2.0 bearer token"
      },
      "endpointId": "Endpoint ID",
      "cookie": {}
    },
    "payload": {
      "percentage": 74
    }
  }
}

SetPercentage directive payload

The following table shows the payload details for the SetPercentage directive.

Field	Description	Type
`percentage`	The percentage to set the device to.	Integer

SetPercentage response

If you handle a SetPercentage directive successfully, respond with an Alexa.Response event. A successful response confirms that the endpoint completed the requested action. You can respond synchronously from your Lambda function or asynchronously through the Alexa event gateway. If you choose to respond asynchronously, include a correlation token and a scope with an authorization token. For details about both response types, see Alexa.Response. In the context object, include the values of all properties that changed. The following example shows a SetPercentage response.

{
  "event": {
    "header": {
      "namespace": "Alexa",
      "name": "Response",
      "messageId": "Unique identifier, preferably a version 4 UUID",
      "correlationToken": "Opaque correlation token that matches the request",
      "payloadVersion": "3"
    },
    "endpoint": {
      "scope": {
        "type": "BearerToken",
        "token": "OAuth2.0 bearer token"
      },
      "endpointId": "Endpoint ID"
    },
    "payload": {}
  },
  "context": {
    "properties": [
      {
        "namespace": "Alexa.PercentageController",
        "name": "percentage",
        "value": 74,
        "timeOfSample": "2017-02-03T16:20:50.52Z",
        "uncertaintyInMilliseconds": 500
      }
    ]
  }
}

SetPercentage directive error handling

If you can’t handle a SetPercentage directive successfully, respond with an Alexa.ErrorResponse event.

AdjustPercentage directive

Support the AdjustPercentage directive so that users can adjust the percentage value of a device setting. The following examples show user utterances:

AdjustPercentage directive payload

The following table shows the payload details for the AdjustPercentage directive.

Field	Description	Type
`percentageDelta`	The amount by which to change the percentage.	Integer

AdjustPercentage directive example

The following example illustrates an AdjustPercentage directive that Alexa sends to your add-on.

{
  "directive": {
    "header": {
      "namespace": "Alexa.PercentageController",
      "name": "AdjustPercentage",
      "messageId": "Unique version 4 UUID",
      "correlationToken": "Opaque correlation token",
      "payloadVersion": "3"
    },
    "endpoint": {
      "scope": {
        "type": "BearerToken",
        "token": "OAuth2.0 bearer token"
      },
      "endpointId": "Endpoint ID",
      "cookie": {}
    },
    "payload": {
      "percentageDelta": -20
    }
  }
}

AdjustPercentage response

If you handle an AdjustPercentage directive successfully, respond with an Alexa.Response event. A successful response confirms that the endpoint completed the requested action. You can respond synchronously from your Lambda function or asynchronously through the Alexa event gateway. If you choose to respond asynchronously, include a correlation token and a scope with an authorization token. For details about both response types, see Alexa.Response. In the context object, include the values of all properties that changed. The following example shows a AdjustPercentage response.

{
  "event": {
    "header": {
      "namespace": "Alexa",
      "name": "Response",
      "messageId": "Unique identifier, preferably a version 4 UUID",
      "correlationToken": "Opaque correlation token that matches the request",
      "payloadVersion": "3"
    },
    "endpoint": {
      "scope": {
        "type": "BearerToken",
        "token": "OAuth2.0 bearer token"
      },
      "endpointId": "Endpoint ID"
    },
    "payload": {}
  },
  "context": {
    "properties": [
      {
        "namespace": "Alexa.PercentageController",
        "name": "percentage",
        "value": 54,
        "timeOfSample": "2017-02-03T16:20:50.52Z",
        "uncertaintyInMilliseconds": 500
      }
    ]
  }
}

AdjustPercentage directive error handling

If you can’t handle an AdjustPercentage 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 the retrievable properties in the context object. You identify your retrievable properties in your discovery response. For details about state reports, see Understand State and Change Reporting.

StateReport response example

{
  "event": {
    "header": {
      "namespace": "Alexa",
      "name": "StateReport",
      "messageId": "Unique identifier, preferably a version 4 UUID",
      "correlationToken": "Opaque correlation token that matches the request",
      "payloadVersion": "3"
    },
    "endpoint": {
      "scope": {
        "type": "BearerToken",
        "token": "OAuth2.0 bearer token"
      },
      "endpointId": "Endpoint ID"
    },
    "payload": {}
  },
  "context": {
    "properties": [
      {
        "namespace": "Alexa.PercentageController",
        "name": "percentage",
        "value": 30,
        "timeOfSample": "2017-02-03T16:20:50.52Z",
        "uncertaintyInMilliseconds": 0
      }
    ]
  }
}

Change reporting

You send a ChangeReport event to report changes proactively in the state of an endpoint. You identify the properties that you proactively report in your discovery response. For details about change reports, see Understand State and Change Reporting.

ChangeReport event example

{  
  "event": {
    "header": {
      "namespace": "Alexa",
      "name": "ChangeReport",
      "messageId": "Unique identifier, preferably a version 4 UUID",
      "payloadVersion": "3"
    },
    "endpoint": {
      "scope": {
        "type": "BearerToken",
        "token": "OAuth2.0 bearer token"
      },
      "endpointId": "Endpoint ID"
    },
    "payload": {
      "change": {
        "cause": {
          "type": "PHYSICAL_INTERACTION"
        },
        "properties": [
          {
            "namespace": "Alexa.PercentageController",
            "name": "percentage",
            "value": 65,
            "timeOfSample": "2024-05-01T19:20:05.05Z",
            "uncertaintyInMilliseconds": 0
          }
        ]
      }
    }
  },
  "context": {
    "namespace": "Alexa.EndpointHealth",
    "name": "connectivity",
    "value": {
      "value": "OK"
    },
    "timeOfSample": "2024-05-01T19:10:22.05Z",
    "uncertaintyInMilliseconds": 0
  }
}

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Developer Reference

Alexa.PercentageController Interface 3

Utterances

Reportable properties

Discovery

Discover response example

Directives

SetPercentage directive

SetPercentage directive example

SetPercentage directive payload

SetPercentage response

SetPercentage directive error handling

AdjustPercentage directive

AdjustPercentage directive payload

AdjustPercentage directive example

AdjustPercentage response

AdjustPercentage directive error handling

State reporting

StateReport response example

Change reporting

ChangeReport event example

​Utterances

​Reportable properties

​Discovery

​Discover response example

​Directives

​SetPercentage directive

​SetPercentage directive example

​SetPercentage directive payload

​SetPercentage response

​SetPercentage directive error handling

​AdjustPercentage directive

​AdjustPercentage directive payload

​AdjustPercentage directive example

​AdjustPercentage response

​AdjustPercentage directive error handling

​State reporting

​StateReport response example

​Change reporting

​ChangeReport event example

​Related topics

Utterances

Reportable properties

Discovery

Discover response example

Directives

SetPercentage directive

SetPercentage directive example

SetPercentage directive payload

SetPercentage response

SetPercentage directive error handling

AdjustPercentage directive

AdjustPercentage directive payload

AdjustPercentage directive example

AdjustPercentage response

AdjustPercentage directive error handling

State reporting

StateReport response example

Change reporting

ChangeReport event example

Related topics