Alexa.HumiditySensor Interface 3

Implement the Alexa.HumiditySensor interface in your Alexa add-on for devices that sense humidity, such as thermostats. Typically you use the Alexa.HumiditySensor interface in conjunction with the Alexa.TemperatureSensor interface. For more details about smart home add-ons, see Connect Your Device Cloud with Smart Home Add-ons. For the list of languages that the Alexa.HumiditySensor interface supports, see List of Alexa Interfaces and Supported Languages. For the definitions of the Alexa message properties, see Alexa Interface Message and Property Reference.

Utterances

The Alexa.HumiditySensor interface doesn’t have any user utterances.

Reportable properties

The Alexa.HumiditySensor interface uses the relativeHumidity property as the primary property. You identify that you support the property in your discovery response. The property is defined as a number (double) between 0 and 100, inclusive.

Discovery

You describe endpoints that support the Alexa.HumiditySensor interface by using the standard discovery mechanism described in Alexa.Discovery. Set retrievable to true for the properties that you report when Alexa sends your add-on a state report request. Set proactivelyReported to true for the properties that you proactively report to Alexa in a change report. Use a display category that’s appropriate for your device, such as TEMPERATURE_SENSOR. For the full list of display categories, see display categories. Sensor devices must also implement Alexa.EndpointHealth.

Discover response example

The following example shows an Alexa.Discover.Response message for a device that supports the Alexa.HumiditySensor 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 name of the endpoint",
                "description": "Description to be shown in the Alexa app",
                "friendlyName": "Weather station",
                "displayCategories": ["TEMPERATURE_SENSOR"],
                "additionalAttributes": {
                    "manufacturer": "Manufacturer name of the endpoint",
                    "model": "Model of the device",
                    "serialNumber": "Serial number of the device",
                    "firmwareVersion": "Firmware version of the device",
                    "softwareVersion": "Software version of the device",
                    "customIdentifier": "Optional custom identifier for the device"
                },
                "capabilities": [{
                        "type": "AlexaInterface",
                        "interface": "Alexa.HumiditySensor",
                        "version": "3",
                        "properties": {
                            "supported": [{
                                "name": "relativeHumidity"
                            }],
                            "proactivelyReported": true,
                            "retrievable": true
                        }
                    },
                    {
                        "type": "AlexaInterface",
                        "interface": "Alexa.TemperatureSensor",
                        "version": "3",
                        "properties": {
                            "supported": [{
                                "name": "temperature"
                            }],
                            "proactivelyReported": true,
                            "retrievable": true
                        }
                    },
                    {
                        "type": "AlexaInterface",
                        "interface": "Alexa.EndpointHealth",
                        "version": "3.2",
                        "properties": {
                            "supported": [{
                                "name": "connectivity"
                            }],
                            "proactivelyReported": true,
                            "retrievable": true
                        }
                    },
                    {
                        "type": "AlexaInterface",
                        "interface": "Alexa",
                        "version": "3"
                    }
                ]
            }]
        }
    }
}

Directives

The Alexa.HumiditySensor interface doesn’t define any directives.

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": "a unique identifier, preferably a version 4 UUID",
            "correlationToken": "an opaque correlation token that matches the request",
            "payloadVersion": "3"
        },
        "endpoint": {
            "scope": {
                "type": "BearerToken",
                "token": "an OAuth2 bearer token"
            },
            "endpointId": "endpoint ID"
        },
        "payload": {}
    },
    "context": {
        "properties": [{
                "namespace": "Alexa.HumiditySensor",
                "name": "relativeHumidity",
                "value": {
                    "value": 89.0
                },
                "timeOfSample": "2023-02-03T16:20:50.52Z",
                "uncertaintyInMilliseconds": 0
            },
            {
                "namespace": "Alexa.TemperatureSensor",
                "name": "temperature",
                "value": {
                    "value": 19.9,
                    "scale": "CELSIUS"
                },
                "timeOfSample": "2023-02-03T16:20:50.52Z",
                "uncertaintyInMilliseconds": 0
            },
            {
                "namespace": "Alexa.EndpointHealth",
                "name": "connectivity",
                "value": {
                    "value": "OK"
                },
                "timeOfSample": "2023-02-03T16:20:50Z",
                "uncertaintyInMilliseconds": 1000
            }
        ]
    }
}

Change reporting

You send an Alexa.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": "a unique identifier, preferably a version 4 UUID",
            "payloadVersion": "3"
        },
        "endpoint": {
            "scope": {
                "type": "BearerToken",
                "token": "an OAuth2 bearer token"
            },
            "endpointId": "endpoint ID"
        },
        "payload": {
            "change": {
                "cause": {
                    "type": "PERIODIC_POLL"
                },
                "properties": [{
                    "namespace": "Alexa.HumiditySensor",
                    "name": "relativeHumidity",
                    "value": {
                        "value": 92.5
                    },
                    "timeOfSample": "2023-02-03T16:20:50.52Z",
                    "uncertaintyInMilliseconds": 0
                }]
            }
        }
    },
    "context": {
        "properties": [{
                "namespace": "Alexa.TemperatureSensor",
                "name": "temperature",
                "value": {
                    "value": 19.9,
                    "scale": "CELSIUS"
                },
                "timeOfSample": "2023-02-03T16:20:50.52Z",
                "uncertaintyInMilliseconds": 0
            },
            {
                "namespace": "Alexa.EndpointHealth",
                "name": "connectivity",
                "value": {
                    "value": "OK"
                },
                "timeOfSample": "2022-06-03T16:20:50Z",
                "uncertaintyInMilliseconds": 0
            }
        ]
    }
}

Get Started

Connect Your Device to Alexa

Certify Your Device

Developer Reference

Utterances

Reportable properties

Discovery

Discover response example

Directives

State reporting

StateReport response example

Change reporting

ChangeReport event example

​Utterances

​Reportable properties

​Discovery

​Discover response example

​Directives

​State reporting

​StateReport response example

​Change reporting

​ChangeReport event example

​Related topics

Utterances

Reportable properties

Discovery

Discover response example

Directives

State reporting

StateReport response example

Change reporting

ChangeReport event example

Related topics