Alexa.EventDetectionSensor Interface 3

Implement the Alexa.EventDetectionSensor interface in your Alexa skill so that you can notify Alexa when your security camera devices detect the presence of a person. When your security camera detects a person, you report that information to Alexa in a change report, and Alexa notifies your user. Users can set up notifications and routines for person detection in the Alexa app. By setting up person detection, users can reduce the number of notifications they receive when tracking all motion detection. For more details about security skills, see Smart Home Security Overview.

You can also support the Alexa.MediaMetadata Interface to enable Alexa to search and display the media clip of the person that is detected. Users can ask Alexa questions like "Alexa, show the last person detected at my front door."

For the list of languages that the EventDetectionSensor 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.EventDetectionSensor and Alexa.MediaMetadata interfaces, the voice interaction model is already built for you. The following examples show some customer utterances:

Alexa, show me the last time someone was at the front door.
Alexa, show me the last time a person was detected at the front door.
Alexa, show me the last person detected at the front door.
Alexa, show me the most recent person at the front door.

After the customer says one of these utterances, Alexa displays the media clip identified in the most recent change report sent by your skill.

Reportable properties

The Alexa.EventDetectionSensor interface uses the humanPresenceDetectionState property as the primary property.

The following example shows the humanPresenceDetectionState property.

Copied to clipboard.

{
    "value": "DETECTED",
    "detectionMethods": ["VIDEO"],
    "media": {
        "type": "ALEXA.MEDIAMETADATA",
        "id": "Media metadata ID"
    }
  }

The following table shows the definition of the humanPresenceDetectionState property.

Field Description Type Required
value Indicates whether the endpoint detects presence.
Valid values are DETECTED or NOT_DETECTED.		 String Yes
detectionMethods Methods that the endpoint used to detect the event.
Valid values are AUDIO, VIDEO.		 Array No
media Identifier of the audio or video recorded for the detection event. Object No

Discovery

You describe endpoints that support Alexa.EventDetectionSensor using the standard discovery mechanism described in Alexa.Discovery.

Set proactivelyReported to true for the properties that you proactively report to Alexa in a change report.

Use CAMERA for the display category. For the full list of display categories, see display categories.

Configuration object

In addition to the usual discovery response fields, for EventDetectionSensor, include a configuration object that contains the following fields.

Field Description Type Required
detectionMethods[] Methods that the endpoint uses to detect events; AUDIO, VIDEO. The default value is ["AUDIO", "VIDEO"]. Array No
detectionModes[] Types of events that the endpoint detects. If you don't specify detectionModes, the default is humanPresence. Array No
detectionModes.
humanPresence.
featureAvailability		 Indicates whether the human presence detection feature is available. The default value is ENABLED.
Valid values: ENABLED, DISABLED, SUBSCRIPTION_REQUIRED		 String No
detectionModes.
humanPresence.
supportsNotDetected		 Indicates whether the endpoint supports the NOT_DETECTED state. The default value is true. Boolean No

Discover response example

The following example shows a Discover.Response message for a security camera that supports Alexa.EventDetectionSensor and Alexa.MediaMetadata.

Copied to clipboard.

{
  "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",
          "displayCategories": ["CAMERA"],
          "cookie": {},
          "capabilities": [
            {
              "type": "AlexaInterface",
              "interface": "Alexa.EventDetectionSensor",
              "version": "3",
              "properties": {
                "supported": [
                  {
                    "name": "humanPresenceDetectionState"
                  }
                ],
                "retrievable": false,
                "proactivelyReported": true
              },
              "configuration": {
                "detectionMethods": ["AUDIO", "VIDEO"],
                "detectionModes": {
                  "humanPresence": {
                    "featureAvailability": "ENABLED",
                    "supportsNotDetected": false
                  }
                }
              }
            },
            {
              "type": "AlexaInterface",
              "interface": "Alexa.MediaMetadata",
              "version": "3",
              "proactivelyReported": true
            },
            {
              "type": "AlexaInterface",
              "interface": "Alexa.EndpointHealth",
              "version": "3",
              "properties": {
                "supported": [
                  {
                    "name":"connectivity"
                  }
                ],
                "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. For example, if human presence detection requires a subscription, your first discovery response indicates that the human presence detection feature is disabled. If the user buys a subscription, send an AddOrUpdateReport message to indicate that the human presence detection feature is now enabled. Also send an AddOrUpdateReport message if the user manually disables human presence detection. For more details, see AddOrUpdateReport.

AddOrUpdateReport event example

Copied to clipboard.

{
  "event": {
    "header": {
      "namespace": "Alexa.Discovery",
      "name": "AddOrUpdateReport",
      "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",
          "displayCategories": ["CAMERA"],
          "cookie": {},
          "capabilities": [
            {
              "type": "AlexaInterface",
              "interface": "Alexa.EventDetectionSensor",
              "version": "3",
              "properties": {
                "supported": [
                  {
                    "name": "humanPresenceDetectionState"
                  }
                ],
                "retrievable": false,
                "proactivelyReported": true
              },
              "configuration": {
                "detectionMethods": ["AUDIO", "VIDEO"],
                "detectionModes": {
                  "humanPresence": {
                    "featureAvailability": "DISABLED",
                    "supportsNotDetected": false
                  }
                }
              }
            },
            {
              "type": "AlexaInterface",
              "interface": "Alexa.MediaMetadata",
              "version": "3",
              "proactivelyReported": true
            },
            {
              "type": "AlexaInterface",
              "interface": "Alexa.EndpointHealth",
              "version": "3",
              "properties": {
                "supported": [
                  {
                    "name":"connectivity"
                  }
                ],
                "proactivelyReported": true,
                "retrievable": true
              }
            },
            {
              "type": "AlexaInterface",
              "interface": "Alexa",
              "version": "3"
            }
          ]
        }
      ]
    }
  }
}

Change report

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 with person detected

The following example shows a change report that you send when you detect human presence.

Copied to clipboard.

{  
  "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.EventDetectionSensor",
            "name": "humanPresenceDetectionState",
            "value": {
              "value": "DETECTED",
              "detectionMethods": ["VIDEO"],
              "media": {
                  "type": "ALEXA.MEDIAMETADATA",
                  "id": "Media metadata ID"
              }
            },
            "timeOfSample": "2017-02-03T16:20:50.52Z",
            "uncertaintyInMilliseconds": 0
          }
        ]
      }
    }
  },
  "context": {
    "properties": [
      {
        "namespace": "Alexa.EndpointHealth",
        "name": "connectivity",
        "value": {
          "value": "OK"
        },
        "timeOfSample": "2017-02-03T16:20:50.52Z",
        "uncertaintyInMilliseconds": 0
      }
    ]
  }
}