Alexa.InventoryUsageSensor Interface

Implement the Alexa.InventoryUsageSensor capability interface so that you can report the amount of a consumable product that your device has used. For example, if your device is a coffee maker that uses coffee pods, you can report the number of pods that your device used to date. You can implement multiple instances of Alexa.InventoryUsageSensor for multiple consumable products, such as a coffee maker with coffee pods and milk or creamer pods.

If you report the quantity of a consumable product remaining in your device, implement the Alexa.InventoryLevelSensor interface instead. If your device contains a consumable product that has an unknown lifespan, implement the Alexa.InventoryLevelUsageSensor interface instead.

For the list of languages that the Alexa.InventoryUsageSensor interface supports, see List of Alexa Interfaces and Supported Languages.

Dash replenishment IDs

You can add the Amazon Dash Replenishment Service to your smart home device to enable Alexa to monitor and reorder supplies or replacement parts for your device. When you report inventory with Alexa.InventoryUsageSensor, your customers can track supply levels within the Alexa app and receive notifications from Alexa when supplies run low or parts need replacement. Also, customers can set up automatic reordering of these supplies. For example, a printer can report ink usage to Alexa so that the customer doesn't run out of ink. For details, see About Dash Replenishment.

When you register your device for Dash replenishment, Amazon supplies a replenishment ID for each consumable product in your device. The replenishment ID identifies the products that the customer can order to replace the consumed product. You can provide these IDs to Alexa in the following ways:

  • If you already have your replenishment IDs at the time of device discovery, provide them in your discovery response.
  • You can provide your replenishment IDs later in an AddOrUpdateReport message.

Reportable properties

The Alexa.InventoryUsageSensor interface doesn't define any reportable properties.

Discovery

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

For the full list of display categories, see display categories.

Capabilities array

In addition to the usual discovery response fields, for each Alexa.InventoryUsageSensor entry in the capabilities array, include the following fields.

Field Description Type
instance Name of the sensor:
Examples: CoffeePod or DetergentPod.		 String
measurement Way you measure the consumable product.
One of count, volume, or weight. For volume and weight, include the unit of measure.		 Object
replenishment The Dash replenishment ID for the consumable product. Object
capabilityResources Friendly names that customers can use to interact with the sensor. CapabilityResources object

Discover response example

The following example shows a Discover.Response message for a coffee maker that supports the Alexa.InventoryUsageSensor interface.

Copied to clipboard.

{
  "event": {
    "header": {
      "namespace": "Alexa.Discovery",
      "name": "Discover.Response",
      "payloadVersion": "3",
      "messageId": "a unique identifier, preferably a version 4 UUID"
    },
    "payload": {
      "endpoints": [
        {
          "endpointId": "unique ID of the endpoint",
          "manufacturerName": "Coffee Maker Plus",
          "description": "Smart Coffee Maker by Coffee Maker Plus",
          "friendlyName": "Coffee maker",
          "displayCategories": [
            "OTHER"
          ],
          "cookie": {},
          "capabilities": [
            {
              "type": "AlexaInterface",
              "interface": "Alexa.InventoryUsageSensor",
              "instance": "Sensor.CoffeePod",
              "version": "3",
              "configuration": {
                "measurement": {
                  "@type": "Count"
                },
                "replenishment": {
                  "@type": "DashReplenishmentId",
                  "value": "replenishment ID for refill options"
                }
              },
              "capabilityResources": {
                "friendlyNames": [
                  {
                    "@type": "text",
                    "value": {
                      "text": "Coffee pods",
                      "locale": "en-US"
                    }
                  },
                  {
                    "@type": "text",
                    "value": {
                      "text": "Capsules de café",
                      "locale": "fr-FR"
                    }
                  }
                ]
              }
            },
            {
              "type": "AlexaInterface",
              "interface": "Alexa.PowerController",
              "version": "3",
              "properties": {
                "supported": [
                  {
                    "name": "powerState"
                  }
                ],
                "retrievable": true,
                "proactivelyReported": 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 you don't have the replenishment IDs for your consumable products at the time of initial device discovery, you can provide the replenishment IDs to Alexa later by sending an AddOrUpdateReport message. For details, see AddOrUpdateReport event.

AddOrUpdateReport event example

Copied to clipboard.

{
  "event": {
    "header": {
      "namespace": "Alexa.Discovery",
      "name": "AddOrUpdateReport",
      "payloadVersion": "3",
      "messageId": "a unique identifier, preferably a version 4 UUID"
    },
    "payload": {
      "endpoints": [
        {
          "endpointId": "unique ID of the endpoint",
          "manufacturerName": "Coffee Maker Plus",
          "description": "Smart Coffee Maker by Coffee Maker Plus",
          "friendlyName": "Coffee maker",
          "displayCategories": [
            "OTHER"
          ],
          "cookie": {},
          "capabilities": [
            {
              "type": "AlexaInterface",
              "interface": "Alexa.InventoryUsageSensor",
              "instance": "Sensor.CoffeePod",
              "version": "3",
              "configuration": {
                "measurement": {
                  "@type": "Count"
                },
                "replenishment": {
                  "@type": "DashReplenishmentId",
                  "value": "replenishment ID for refill options"
                }
              },
              "capabilityResources": {
                "friendlyNames": [
                  {
                    "@type": "text",
                    "value": {
                      "text": "Coffee pods",
                      "locale": "en-US"
                    }
                  },
                  {
                    "@type": "text",
                    "value": {
                      "text": "Capsules de café",
                      "locale": "fr-FR"
                    }
                  }
                ]
              }
            },
            {
              "type": "AlexaInterface",
              "interface": "Alexa.PowerController",
              "version": "3",
              "properties": {
                "supported": [
                  {
                    "name": "powerState"
                  }
                ],
                "proactivelyReported": true,
                "retrievable": true
              }
            },
            {
              "type": "AlexaInterface",
              "interface": "Alexa",
              "version": "3"
            }
          ]
        }
      ]
    }
  }
}

Inventory update events

ChangeReport

When you implement the Alexa.InventoryUsageSensor interface, you send InventoryConsumed events instead of the typical ChangeReport event. For details about change reports, see Understand State and Change Reporting.

InventoryConsumed event

To report inventory proactively to Alexa, send an InventoryConsumed event and include the amount of the consumable products that your device has already consumed. You send the event to the Alexa event gateway.

InventoryConsumed event example

In the following example you notify Alexa after the user has consumed a coffee pod.

Copied to clipboard.

{  
  "event": {
    "header": {
      "namespace": "Alexa.InventoryUsageSensor",
      "name": "InventoryConsumed",
      "instance": "Sensor.CoffeePod",
      "messageId": "a unique identifier, preferably a version 4 UUID",
      "payloadVersion": "3"
    },
    "endpoint": {
      "scope": {
        "type": "BearerToken",
        "token": "an OAuth2 bearer token"
      },
      "endpointId": "endpoint ID"
    },
    "payload": {
      "usage": {
        "@type": "Count",
        "value": 1
      },
      "timeOfSample": "2020-09-23T16:20:50Z"
    }
  }
}

InventoryConsumed event payload

Field Description Type Required
usage Amount of the consumable product that has been used, expressed as a count, volume, or weight. For volume and weight, include the unit of measure. Object Yes
timeOfSample Time the inventory was consumed, specified in UTC.
Defined in ISO 8601 format, YYYY-MM-DDThh:mm:ssZ.		 String Yes