How the Alexa Connect Kit Works

Discover how the different components of the Alexa Connect Kit (ACK) work together and how users interact with your ACK-based device.

To learn about the benefits and features that ACK offers, see What's the Alexa Connect Kit.

How ACK connects to Alexa

If you want to connect to Alexa with ACK, Amazon provides the components to you out-of-the-box, as shown in the following diagram, Connecting to Alexa Using ACK. Here, you don't have to build an Alexa skill, cloud infrastructure, or a mobile app. Instead, ACK managed services handle these components for you. If you want to connect to an Alexa service without ACK, you might have to build these components yourself. Typically, these components aren't provided to you out-of-the-box, as shown in the following diagram, Connecting to Alexa Without ACK. In some scenarios, building and maintaining your own services can offer more flexibility, but they typically require more resources to maintain.

Components of an ACK-based smart device
Components of an ACK-based smart device

Components of an ACK-based device

Products built with ACK include the following components:

  • An application, installed on the System-on-Chip (SoC) on your device, that includes the ACK SDK and Alexa capabilities. The SDK is a C-language SDK developed by Amazon that includes tools, libraries, example apps, and documentation for developers to build Alexa-connected device applications. The libraries include software that can connect to the ACK managed services hosted on the Amazon Web Services (AWS) cloud. The ACK SDK for Matter also includes the Connectivity Standards Alliance (CSA) Matter SDK.

  • For the ACK Module solution only, a host microcontroller unit (HMCU) that runs your application logic on your ACK-based device. You can use a HCMU of your choice or select from pre-integrated HMCU kits to speed up your development.

  • Virtual product that represents your physical product in the cloud and defines how users can interact with your device. When you create or edit a virtual product, you choose its Alexa capabilities and define aspects of the Alexa app experience. You associate the virtual product with your physical product in a process called provisioning.

  • The Smart Home APIs to communicate to Alexa to control device behavior. These APIs use predefined utterances that the customers use to control your device. For more details, see Pre-built voice interaction models. Alexa services that convert customer utterances into directives, register ACK-based devices with Alexa accounts, and provide access to other Alexa capabilities and features. These services aren't specific to ACK.

  • ACK managed services that provide product-specific functions, such as management of the device fleet, over-the-air updates, and device configuration. ACK also includes the ACK developer console where you can create and edit virtual products, view and edit the Alexa interfaces associated with your product, and download resources, such as the ACK Device SDK. You use the ACK console for ACK-based devices that use the ACK module and ACK SDK solutions. As your service provider and data processor, Amazon delivers cloud-based ACK managed services, and partner-specific and device-specific backend functionality.

High-level interaction between ACK-based devices and users

Users can control your ACK product with voice utterances and the Alexa app. The following diagram shows the high-level interaction between a user and Alexa to control your ACK-based device. This diagram uses most of the ACK components listed in the previous section.

Interactions on an ACK-based smart device

The following example interactions explains what happens when a user turns on a kitchen fan built with ACK. These examples show the steps for ACK SDK for Matter, ACK SDK, and the ACK module solutions.


  1. A user says "Alexa, turn on my kitchen fan."
  2. The Alexa services interpret the utterance and send a directive to the Matter-enabled Amazon Echo device to turn on the kitchen fan. In this example, Alexa services send an Alexa.PowerController.TurnOn directive.
  3. The Matter-enabled Echo converts the Alexa directive to the corresponding Matter command and sends the Matter command to your ACK-based device through Wi-Fi to turn on the kitchen fan motor.
  4. The device application receives the Matter command by using functionality provided by the ACK SDK for Matter.
  5. The device application communicates with device hardware to turn on the kitchen fan motor.
  6. The kitchen fan turns on.
  7. The device application sends a Matter response to the Echo device.
  8. The Echo device converts the Matter response to an Alexa response and sends the response to Alexa.
  9. The device application might use the ACK SDK to record any interactions with the device, such as operational metrics.


  1. A user says "Alexa, turn on my kitchen fan."
  2. The Alexa services interpret the utterance and send a directive to the ACK managed services to turn on the kitchen fan. In this example, Alexa services send an Alexa.PowerController.TurnOn directive.
  3. The ACK managed services communicate to your ACK-based device through Wi-Fi and route the message to the ACK SDK.
  4. The device application receives the directive by using functionality provided by the ACK SDK.
  5. The device application communicates with device hardware to turn on the kitchen fan motor.
  6. The kitchen fan turns on.
  7. The device application tells the ACK SDK that it processed the directive and returns the status of the device.
  8. The device application might use the ACK SDK to record any interactions with the device, such as operational metrics.


  1. A user says "Alexa, turn on my kitchen fan."
  2. The Alexa services interpret the utterance and send a directive to the ACK managed services to turn on the kitchen fan. In this example, Alexa services send an Alexa.PowerController.TurnOn directive.
  3. The ACK managed services communicate to your ACK-based device through Wi-Fi and route the message to the ACK module.
  4. In the two chip solution, the ACK module forward the directive to the HMCU.
  5. The HMCU application receives the directive by using functionality provided by the ACK Device SDK.
  6. The HMCU application communicates with device hardware and turns on the kitchen fan motor.
  7. The kitchen fan turns on.
  8. The HMCU application tells the ACK Device SDK that it processed the directive and returns the status of the device.
  9. The HMCU application might use the ACK Device SDK to record any interactions with the device, such as operational metrics.

How ACK-based devices interact with Alexa

ACK-based devices interact with Alexa services by using a combination of an ACK SDK and the Alexa Smart Home Skill API.

ACK SDK options

You can choose one of the following ACK SDKs to connect your product to Alexa:

  • Use the ACK SDK for Matter to integrate Matter-related command and control communication .
  • Use the ACK SDK APIs to implement your Alexa-connected solution.
  • Use the ACK Device SDK APIs and the ACK module with integrated Amazon firmware to build your HMCU application to respond and act on Alexa directives. For details about how to set up and use the SDK, see ACK Device SDK.

Smart home APIs

ACK-based devices use the Alexa Smart Home Skill API capability interfaces to communicate to Alexa. With these capability interfaces, you can control different properties of your ACK-based device.

The following table provides some examples of the interfaces you can use with an ACK-based device.

Feature Description Capability interface

Color

Control the color of a device, such as a smart lamp.

ColorController

Power

Control the power state of a device.

PowerController

Range

Control settings on a device, represented by numbers within a minimum and maximum range.

ModeController

How users interact with ACK-based devices

A user that interacts with an ACK-based device manually, with Alexa by speaking to an Alexa-enabled device, or by using the Alexa app. With the Alexa app, you define your app experience in the ACK developer console when you create a virtual device.

Predefined utterances

To interact with your device, users use predefined utterances made available through the Alexa Smart Home Skill API capability interfaces. When you build an ACK-based device, you don't have to define your own set of utterances or spend time creating a new voice interaction model. These configurations are available for you to use out-of-the box with the Alexa Smart Home Skill API.

The following table provides examples of how a user might interact with your ACK-based device. For ideas about how to combine different Alexa interfaces in your products, see Get Started with Device Templates.

Example product Example utterance Description Capability interface

Tea kettle

"Alexa, turn on the tea kettle."

Controls the power of the kettle.

PowerController

Color changer

"Alexa, change the bedroom light to white."

Changes the color of a smart lamp.

ColorController

Fan

"Alexa, set the fan speed to high."

Sets the speed of the fan.

RangeController

Configure and manage your ACK-based devices

After you release your device, use the ACK developer console to download logs, view analytics, and update some device configuration. Contact the ACK support team to manage firmware updates and device configuration. For more details about accessing the ACK console, see Create Your Amazon Developer Account.

The image shows the ACK console with the menu on the left and the welcome page in the center.
Example of the ACK developer console
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Last updated: Nov 27, 2023