Alexa.Response Interface 3
When you handle an Alexa directive successfully, respond with a response event. The most generic response event is Alexa.Response
. Some directives have more specific response events. For example, the Alexa.ReportState
directive requires an Alexa.StateReport
response, but the Alexa.PowerController
directives use Alexa.Response
. To determine the correct response to use, check the documentation for your specific interface and directive.
If you can't handle a directive successfully, respond with an Alexa.ErrorResponse event instead.
For the definitions of the message properties, see Alexa Interface Message and Property Reference.
Types of responses
The Alexa
interface supports three types of responses:
- Synchronous – You respond to the directive from your Lambda function.
- Asynchronous – You send a response event from your device cloud to the Alexa event gateway.
- Deferred – For devices that make physical changes, such as a lock, that take longer than eight seconds, send a deferred response before you send your regular synchronous or asynchronous response.
Synchronous response
Specify the following information in a synchronous response.
- Identify the endpoint for the response in the
endpoint
object. - Include the
correlationToken
set to the value from the directive request. - Include response properties in the
payload
object. - In the
context
object of your response, include the values of all the properties of the endpoint that changed and the time of the change. Also, include the values of properties that didn't change, to give Alexa the complete current state of the endpoint.
Synchronous response example
The following example shows a standard synchronous response. In this example, the endpoint supports the Alexa.PowerController
interface and responds to the TurnOn
directive.
{
"event": {
"header": {
"namespace": "Alexa",
"name": "Response",
"messageId": "Unique identifier, preferably a version 4 UUID",
"correlationToken": "Opaque correlation token that matches the request",
"payloadVersion": "3"
},
"endpoint": {
"endpointId": "Endpoint ID"
},
"payload": {}
},
"context": {
"properties": [
{
"namespace": "Alexa.PowerController",
"name": "powerState",
"value": "ON",
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 500
}
]
}
}
Synchronous response properties
Property | Description | Type | Required |
---|---|---|---|
|
Defines header and endpoint information. |
|
Yes |
|
Identifies the response and interface. |
|
Yes |
|
Identifies the endpoint. |
String |
Yes |
|
Identifies the properties required in the response. |
Object |
Yes |
|
Include to return the current state of all the retrievable properties, including the properties that didn't change. |
|
No |
Asynchronous response
When you respond asynchronously, you send an HTTP request to the Alexa event gateway. In the request body, you include the response event. Your response must include the access token that authenticates your skill customer to Alexa.
Specify the following information in an asynchronous response:
- Identify the endpoint for the report in the
endpoint
object. - Include the
correlationToken
set to the value from the directive request. - Include the access token in the
endpoint.scope
object. - Include response properties in the
payload
object. - In the
context
object of your response, include the values of all the properties of the endpoint that changed and the time of the change. Also, include the values of properties that didn't change, to give Alexa the complete current state of the endpoint.
Asynchronous response example
The following example shows an asynchronous response. In this example, the endpoint supports the Alexa.ColorTemperatureController
interface.
POST /v3/events HTTP/1.1
Host: api-amazonalexa.com
Authorization: Bearer access-token-from-Amazon
Content-Type: application/json
{
"event": {
"header": {
"namespace": "Alexa",
"name": "Response",
"messageId": "Unique identifier, preferably a version 4 UUID",
"correlationToken": "Opaque correlation token that matches the request",
"payloadVersion": "3"
},
"endpoint": {
"scope": {
"type": "BearerToken",
"token": "access-token-from-Amazon"
},
"endpointId": "Endpoint ID"
},
"payload": {}
},
"context": {
"properties": [
{
"namespace": "Alexa.ColorTemperatureController",
"name": "colorTemperatureInKelvin",
"value": 5500,
"timeOfSample": "2017-02-03T08:00:00.10Z",
"uncertaintyInMilliseconds": 500
}
]
}
}
Asynchronous response properties
Property | Description | Type | Required |
---|---|---|---|
|
Defines header and endpoint information. |
|
Yes |
|
Identifies the response and interface. |
|
Yes |
|
Identifies the endpoint. |
String |
Yes |
|
Access token for the Alexa event gateway. For details, see Request Access Tokens. |
|
Yes |
|
Identifies the properties required in the response. |
Object |
Yes |
|
Include to return the current state of all the retrievable properties, including the properties that didn't change. |
|
No |
When you send an asynchronous Alexa.Response
to the gateway, Alexa sends an HTTP status code to indicate success or failure.
HTTP status codes
The following table shows the HTTP status code values that your skill might receive from the Alexa event gateway. If you receive an error, the payload
object contains a code
and description
field. Use these fields for logging only.
Status | Payload code | Description |
---|---|---|
|
— |
Request is authorized and the message is a syntactically valid event. The gateway accepted the event for further logical validation and processing. |
|
|
Message is invalid due to missing fields, incorrect values, or malformed JSON. Check your messages against the documentation to verify that your message contains all the required fields. |
|
|
Message didn't include the authorization token or the token is invalid, expired, or malformed. Refresh your token and retry the request. If a user disables your skill, that also invalidates the access token. Here, the user revoked authorization, and you can stop sending change reports for them. |
|
|
You're not allowed access to the event gateway. Make sure that you're sending the events to the correct regional endpoint. For example, send events in North America to the North American endpoint. |
|
|
Token doesn't have the required permissions. Make sure that the skill has permission to send Alexa events. For details, see Request Access to the Alexa Event Gateway. |
|
|
Account record associated with this directed identifier doesn't exist or has expired. This error can occur if the event was sent too late or with an invalid directed identifier. Verify that the directed identifier and authorization code are correct. |
|
|
Skill ID associated with this token wasn't found. This error occurs when user's access token was generated when the skill was in different stage, such as certification. Try disabling and re-enabling the skill for this user. |
|
|
Size of the event payload is too large. The maximum number of endpoints allowed in a request is 300. Send your message with smaller payloads. |
|
|
Number of requests is too high. Resend the message up to three times, with at least a one-second interval between each send attempt. |
|
|
Error occurred with Alexa, and the message wasn't processed. Resend the message up to three times, with at least a one-second interval between each send attempt. If problems persist, contact Amazon Support. |
|
|
Alexa couldn't accept the message. Resend the message up to three times, with at least a one-second interval between each attempt. If the problem persists, contact Amazon Support. |
Example 401 Unauthorized response body
The following example shows an error response.
HTTP/1.1 400 Bad Request
Date: Wed, 07 Mar 2018 20:25:31 GMT
Connection: close
{
"header": {
"namespace": "System",
"name": "Exception",
"messageId": "90c3fc62-4b2d-460c-9c8b-77251f1698a0"
},
"payload": {
"code": "INVALID_ACCESS_TOKEN_EXCEPTION",
"description": "The access token is invalid, expired, or malformed."
}
}
Deferred response
Usually, Alexa waits for your response for eight seconds before timing out. Exceptions are noted in the documentation for individual interfaces. If your response takes more than eight seconds, first send a synchronous Alexa.DeferredResponse
event, and then follow it with a Alexa.Response
, either synchronous or asynchronous.
Alexa.DeferredResponse
is only supported for some interfaces. Check the documentation for your specific interface to determine if the interface supports a deferred response. For example, Alexa.LockController
supports Alexa.DeferredResponse
events.
Because you always send a Alexa.DeferredResponse
synchronously, don't include an endpoint.scope
.
Deferred response example
The following example shows a deferred response that estimates an Alexa.Response
within seven seconds.
{
"event": {
"header": {
"namespace": "Alexa",
"name": "DeferredResponse",
"messageId": "Unique identifier, preferably a version 4 UUID",
"correlationToken": "Opaque correlation token that matches the request",
"payloadVersion": "3"
},
"endpoint": {
"endpointId": "Endpoint ID"
},
"payload": {
"estimatedDeferralInSeconds": 7
}
}
}
Deferred response properties
Property | Description | Type | Required |
---|---|---|---|
|
Defines header and endpoint information. |
|
Yes |
|
Identifies the response and interface. |
|
Yes |
|
Identifies the endpoint. |
String |
Yes |
|
Identifies the deferred response properties. |
Object |
Yes |
|
The approximate time before you send your second response, in seconds. |
Integer |
No |
Related topics
Last updated: Aug 23, 2024