Build a Skill End-to-end Using an Alexa-hosted Skill

When you create an Alexa skill, you store your code and resources yourself. However, you can create an Alexa-hosted skill, and Alexa stores your code and resources on AWS for you. With an Alexa-hosted skill, you can get started quickly by using one of the skill templates available in the developer console. When you create an Alexa-hosted skill, you develop your skill in an online code editor in the developer console. You can also use the Alexa Skills Kit Command Line Interface (ASK CLI) to create and manage Alexa-hosted skills.

You can only build a skill that uses a custom voice interaction model as an Alexa-hosted skill. Currently, you can't create an Alexa-hosted skill that uses a pre-built voice interaction model, such as a Smart Home skill.

Overview

With an Alexa-hosted skill, you can build, edit, and publish a skill without leaving the developer console. You use the online code editor to edit the code for your skill and deploy it directly to your AWS Lambda endpoints. You can build an Alexa-hosted skill with Node.js version 10.x or Python version 3.7. When you create your skill, you select the runtime for your skill. After you choose the runtime for a skill, you can't change it.

When you create an Alexa-hosted skill, Alexa provisions the following:

  • AWS Lambda endpoints in all three Alexa service regions
  • An Amazon S3 bucket for media storage
  • An Amazon S3-backed key-value table for managing session persistence
  • An AWS CodeCommit repository

You can provision your S3 resources close to your skill users to reduce the perceived latency of your skill. For more information, see Hosting your skill resources in different AWS Regions.

You can create an Alexa-hosted skill in the following ways:

You don't need an AWS account to create an Alexa-hosted skill. Alexa provisions the AWS resources that you need directly from the Alexa developer console. Alexa places your files and resources in an individual account, separate from the accounts of other users, and your files are never shared with other users. If you want to use additional AWS services, or if your usage exceeds the usage limits, you can provision the additional resources in your own AWS account. For more information, see Use Personal AWS Resources with Your Alexa-hosted Skill.

When you create your skill, you get an AWS CodeCommit repository for managing your code, which you can access by using the ASK CLI to edit your skill. For more information, see Create and Manage Alexa-hosted Skills Using the ASK CLI.

Hosting your skill resources in different AWS Regions

To reduce perceived latency when accessing your skill, Alexa provisions three AWS Lambda endpoints for your Alexa-hosted skill. Alexa provisions a Lambda endpoint for your skill in each of the following regions:

  • US East (N. Virginia) us-east-1
  • Europe (Ireland) eu-west-1
  • US West (Oregon) us-west-2

You can provision your Amazon S3 resources in any of these regions. We recommend that you choose the region closest to your users by using the following table. The table also determines the default hosting region that appears in the console when you create your skill.

Language Marketplace Recommended AWS Region
English (AU) .com.au US West (Oregon) us-west-2
English (CA) .ca US East (N. Virginia) us-east-1
English (IN) .in Europe (Ireland) eu-west-1
English (UK) .co.uk Europe (Ireland) eu-west-1
English (US) .com US East (N. Virginia) us-east-1
French (CA) .ca US East (N. Virginia) us-east-1
French (FR) .fr Europe (Ireland) eu-west-1
German (DE) .de Europe (Ireland) eu-west-1
Hindi (IN) .in Europe (Ireland) eu-west-1
Italian (IT) .it Europe (Ireland) eu-west-1
Japanese (JP) .com.jp US West (Oregon) us-west-2
Portuguese (BR) .com.br US East (N. Virginia) us-east-1
Spanish (ES) .es Europe (Ireland) eu-west-1
Spanish (MX) .com.mx US East (N. Virginia) us-east-1
Spanish (US) .com US East (N. Virginia) us-east-1

Usage limits

Your developer.amazon.com account is limited to 75 Alexa-hosted skills. When there are 75 Alexa-hosted skills on your account, you must delete an existing Alexa-hosted skill from your account before you can create another Alexa-hosted skill.

Your Alexa-hosted skill uses AWS resources. Your resource usage is limited to the AWS Free Tier. The following limits apply to each Alexa account.

  • AWS Lambda: 1 million free AWS Lambda requests and 3.2 million seconds of compute time per month.
  • Amazon S3: 5 GB of Amazon S3 storage, 20,000 get requests, 2,000 put requests, and 15 GB of data transfer out per month.
  • AWS CodeCommit: 50 GB-month of storage and 10,000 Git requests per month.

The monthly AWS usage for your hosted skills appears on the Hosting page of the Alexa developer console. You can also see your Amazon S3 storage usage at the bottom of the code editor tab for your skill as Media storage: S3 [n.n/5GB]. Usage includes storage of media files and data for session persistence.

If your usage exceeds the AWS Free Tier limits, you have 30 days to bring usage under the limit by moving at least one of your skills to a personal AWS account or other cloud services account. If you don't bring your usage under the specified limits, your skill might be removed from the Alexa skill store. If your skill is flagged as abusing provisioned resources, your skill might be removed from the skill store before 30 days.

Create an Alexa-hosted skill in the console

You can create an Alexa-hosted skill in the developer console by using the procedure that follows. Alternatively, you can use the following methods:

To create an Alexa-hosted skill in the console

  1. Open the Alexa developer console and log in.
  2. Click Create Skill. The Create a new skill page appears.
  3. At the top of the page, for Hosting region, accept the default or choose a new hosting region. The hosting region determines the location of your Amazon S3 bucket. For more information, see Hosting your skill resources in different AWS Regions.
  4. For Skill name, enter a name.
  5. For Default language, choose a language.
  6. For Choose a model to add to your skill, select Custom.
  7. For Choose a method to host your skill's backend resources, select Alexa-Hosted (Node.js) or Alexa-Hosted (Python).
  8. Click Create Skill. The Choose a template to add to your skill page appears.
  9. Choose a template and click the Continue with template button, or click the Import skill button. For more information, see Import an Alexa-hosted Skill from a Public Git Repository. After about one or two minutes, your skill appears in the console open to the Build page.

After you create your skill, the voice model, AWS resources, and code editor are activated, and the developer console initiates a build process for the voice model.

You can store audio and visual files in Amazon S3 to use with your Alexa-hosted skill. For more information, see Use Media Files with Your Alexa-Hosted Skill.

You can store session data in Amazon S3 to use with your Alexa-hosted skill. For more information, see Use Session Persistence with Your Alexa-hosted Skill.

Convert an existing skill to an Alexa-hosted skill

You can convert an existing custom-model skill to an Alexa-hosted skill in the developer console by using the procedure that follows.

To convert an existing skill to an Alexa-hosted skill in the console

  1. Open the Alexa developer console and log in.
  2. In your skill list, click the name of your skill, or in the Actions column, choose Edit.
  3. Click Code to open the code page.
  4. Click Convert to Alexa-hosted. The Convert to Alexa-hosted dialog appears.
  5. For Programming language, choose Node.js or Python.
  6. For Hosting Region, choose the primary hosting region. The hosting region determines the location of your Amazon S3 bucket. For more information, see Hosting your skill resources in different AWS Regions.
  7. Click Convert. After about one or two minutes, the console opens to the Code page.

After your skill is converted to an Alexa-hosted skill, you must manually copy your skill code into the code editor. After your code is ready, click Deploy to build and deploy your skill code.

You can always revert your skill to self-hosted. For details, see Convert from Alexa-hosted to self-hosted.

Skill endpoints and deployment

Alexa provisions an AWS Lambda endpoint for your Alexa-hosted skill in each Alexa service region. If you change the default hosted endpoint for your skill, your skill is no longer an Alexa-hosted skill and the code editor in the console does not deploy to the new endpoint. If you change the default endpoint, you can revert to the Alexa-hosted endpoints by using the option in the code editor in the console.

After your Alexa-hosted skill is published, two stages of your skill appear in the console: one for the live stage and one for the development stage. In the development stage for your skill, you can use the code editor to edit, save and deploy code to the development version of your AWS Lambda endpoint. This action does not affect the live endpoint for your skill. You can then go to the Test tab and test your changes.

If you change the voice model for your skill, you must submit your skill for re-certification. If you change only the code for your skill, you can promote code from development to live by clicking the Promote to live button in the code editor. This action replaces the live code for your published skill.

To make a quick fix to live code for an Alexa-hosted skill, we recommend that you first make changes in the development stage, test the changes, and then promote the changes to the live endpoint for your skill. If you want to make a quick fix to your live code and your development code has other changes that you do not want to promote, you can make your fix directly to the live endpoint. However, you are not able to test your changes first. To make a fix directly to your live endpoint, open the code editor for the live stage, edit your code, and then click Deploy to live.

Add dependencies

Alexa provisions AWS CodeBuild as part of your skill to run the build script. NPM (Node.js) or pip (Python) runs automatically as part of the build script. You can add new libraries and dependencies to your skill, and dependencies are fetched and built when you click the Deploy button.

  • Node.js — Add dependencies in the dependencies section of your package.json file:

    "i18next": "^10.5.0"
    
  • Python — Add dependencies in the dependencies section of your requirements.txt file. For example:

    boto3==1.9.216
    

View Amazon CloudWatch logs

Your Alexa-hosted skill automatically provides you with Amazon CloudWatch logs so you can access information critical to developing your skill.

For skills with Alexa-hosted endpoints in multiple regions, Cloudwatch logs appear separately for each region from which users access your skill. Logs that you generate when you test your skill by using the Test page in the console appear with the CloudWatch logs in the default hosting region for your skill. You choose the default hosting region for your skill when you create your skill, and afterwards it appears on the Endpoint tab of the Build page for your skill.

To view your CloudWatch logs

  1. Open the Alexa developer console and log in.
  2. In the list of your skills, click the name of the skill that you want to view.
  3. Click the Code tab.
  4. In the lower left corner, click the link Logs: Amazon CloudWatch. A limited view of the AWS console opens and your logs appear.
  5. Change the region in the AWS console to see the logs for your skill in other regions.

Convert from Alexa-hosted to self-hosted

If you have an Alexa-hosted skill and you want to host it yourself, you must move any resources hosted in Amazon S3 from your Alexa-hosted skill to your own storage, manually move your code to your new skill endpoint, and change the endpoint of your skill in the developer console. You can download your skill to help convert your skill from Alexa-hosted to self-hosted.

Download your skill

You can download your skill from the Code tab of your skill, either in the development stage or the live stage. In the development stage, you can download the skill with the latest code changes. In the live stage, you can download a copy of the live skill. The download package includes the skill's interaction model, source code files, and skill manifest.

To download a copy of your skill

  1. Open the Alexa developer console and log in.
  2. In the list of your skills, click the name of the skill that you want to download.
  3. Click the Code tab.
  4. In the upper left corner, click the Download Skill icon.
  5. In the pop-up window, choose Continue.
  6. Save your skill as a .zip file.

Filter out skill availability checks

The hosted skills service periodically sends an availability check to your AWS Lambda function to verify that calls to AWS Lambda from your Alexa-hosted skill work properly. Alexa sends the availability check in the form of a LaunchRequest from the user alexa-lambda-availability. If your skill performs an action when it receives a LaunchRequest, filter out requests from the user alexa-lambda-availability to prevent your skill from performing unnecessary actions.

The following code illustrates an availability check sent from Alexa to your skill.

{
  "version": "1.0",
  "session": {
    "new": true,
    "sessionId": "alexa-lambda-availability",
    "application": {
      "applicationId": "YOUR_SKILL_ID"
    },
    "user": {
      "userId": "alexa-lambda-availability"
    }
  },
  "context": {
    "AudioPlayer": {
      "playerActivity": "IDLE"
    },
    "System": {
      "application": {
        "applicationId": "YOUR_SKILL_ID"
      },
      "user": {
        "userId": "alexa-lambda-availability"
      },
      "device": {
        "deviceId": "test-device",
        "supportedInterfaces": {
          "AudioPlayer": {}
        }
      },
      "apiEndpoint": "https://api.amazonalexa.com",
      "apiAccessToken": "{token}"
    }
  },
  "request": {
    "type": "LaunchRequest",
    "requestId": "amzn1.echo-api.request.alexa.lambda.availability",
    "locale": "en-US",
    "shouldLinkResultBeReturned": false
  }
}