AudioPlayer Interface Reference

The AudioPlayer interface provides directives and requests for streaming audio and monitoring playback progression. Your skill can send directives to start and stop the playback. The Alexa service sends your skill AudioPlayer requests to give you information about the playback state, such as when the track is nearly finished, or when playback starts and stops. Alexa also sends PlaybackController requests in response to hardware buttons, such as on a remote control or the next and previous tap controls on Alexa-enabled devices with a screen.

For more details about the audio player, see Stream Long-Form Audio with AudioPlayer.

Directives and requests

The AudioPlayer interface includes the following directives responses and request types. You include the directives in a response to Alexa to start and stop an audio stream. Alexa sends the requests to notify your skill about changes to the playback state.

Play directive

Send Alexa a request to stream the audio file identified by the specified audioItem. Use the playBehavior parameter to indicate whether to play the stream immediately or to add the stream to the queue. Add the Play directive in your response to Alexa. Include the directive in the directives array in your response.

When you send a Play directive, set the shouldEndSession flag in the response object to true to end the session. If you set this flag to false, Alexa sends the stream to the device for playback, and then pauses the stream to listen for the user's response.

Example directive response

The following example shows a directive entry in your response. For the full response format, see Response Format.

{ "type": "AudioPlayer.Play", "playBehavior": "valid playBehavior value such as ENQUEUE", "audioItem": { "stream": { "url": "https://cdn.example.com/url-of-the-stream-to-play", "token": "opaque token representing this stream", "expectedPreviousToken": "opaque token representing the previous stream", "offsetInMilliseconds": 0, "captionData":{ "content": "WEBVTT\n\n00:00.000 --> 00:02.107\n<00:00.006>My <00:00.0192>Audio <00:01.232>Captions.\n", "type": "WEBVTT" } }, "metadata": { "title": "title of the track to display", "subtitle": "subtitle of the track to display", "art": { "sources": [ { "url": "https://cdn.example.com/url-of-the-album-art-image.png" } ] }, "backgroundImage": { "sources": [ { "url": "https://cdn.example.com/url-of-the-background-image.png" } ] } } } } 

Directive parameters

{ "art": { "sources": [ { "url": "https://cdn.example.com/url-of-the-album-art-image.png" } ] } } 

{ "backgroundImage": { "sources": [ { "url": "https://cdn.example.com/url-of-the-background-image.png" } ] } } 

Playlist progression with ENQUEUE

The audioItem.stream.expectedPreviousToken property is required if playBehavior is ENQUEUE to handle situations in which requests to progress through a playlist and change tracks happen at the same time. The value of audioItem.stream.expectedPreviousToken should match the audioItem.stream.token property provided with the previous stream.

For example:

1. The skill is streaming track 2 in a playlist of several tracks.
2. The user says "Alexa, go back," which sends an AMAZON.PreviousIntent.
3. At about the same time, track 2 is nearly finished, so Alexa sends a PlaybackNearlyFinished request.
4. The skill handles the AMAZON.PreviousIntent first and sends a new Play directive with track 1. This track begins playing. The already-sent PlaybackNearlyFinished request is now outdated, since it assumed that track 2 was playing.
5. The skill handles the now-outdated PlaybackNearlyFinished request and sends a Play directive with track 3, since this is the next track after the originally playing track 2. This request includes expectedPreviousToken set to track 2.
6. The expectedPreviousToken provided in the directive doesn't match the token for the actively playing stream, so the device ignores this directive.
7. As track 1 finishes, Alexa sends a PlaybackNearlyFinished request. The skill responds with a Play directive for track 2. This track begins playing once track 1 finishes.

If this check wasn't in place, the directive sent in step 5 would put track 3 on the queue, which would cause the audio to skip from track 1 to track 3 when track 1 finishes.

Guidelines for images for Alexa-enabled devices with a screen

If you provide images in the audioItem.metadata.art and audioItem.metadata.backgroundImage properties, note the following guidelines:

• When you send a track with new metadata, be sure to also change the audioItem.stream.token property for the track.
• Your image must meet the requirements for an audio image. For more details, see Image requirements and recommendations.
• For the audioItem.metadata.art, use a square image for the best results. If the image isn't square, it's displayed with extra black space on the device. Note that the image is cropped to a circle shape on the Echo Spot (original 2017 release).
• You can provide multiple image URLs in the source array. The device selects the image with the highest resolution to display.

Stop directive

Stops the current audio playback. Include the directive in the directives array in your response.

Example directive response

The following example shows a directive entry in your response. For the full response format, see Response Format.

{ "type": "AudioPlayer.Stop" } 

Directive parameters

ClearQueue directive

Clears the audio playback queue. You can set this directive to clear the queue without stopping the currently playing stream, or clear the queue and stop any currently playing stream. Include the directive in the directives array in your response.

Example directive response

The following example shows a directive entry in your response. For the full response format, see Response Format.

{ "type": "AudioPlayer.ClearQueue", "clearBehavior" : "valid clearBehavior value such as CLEAR_ALL" } 

Directive parameters

PlaybackStarted request

Sent when Alexa begins playing the audio stream previously sent in a Play directive. This request lets your skill verify that playback started successfully. Also, Alexa sends this request to notify your skill when Alexa resumes playback after pausing it for a voice request.

Example request

{ "version": "1.0", "context": { "System": { "application": {}, "user": {}, "device": {} } }, "request": { "type": "AudioPlayer.PlaybackStarted", "requestId": "unique.id.for.the.request", "timestamp": "timestamp of request in format: 2018-04-11T15:15:25Z", "token": "token representing the currently playing stream", "offsetInMilliseconds": 0, "locale": "a locale code such as en-US" } } 

Request parameters

For the full request format, see Request Format.

Response

Your skill can respond to PlaybackStarted with a Stop or ClearQueue directive.

The response cannot include:

• Any standard properties such as outputSpeech, card, or reprompt.
• Any other AudioPlayer directives.
• Any other directives from other interfaces, such a [Dialog directive][dialog-interface-reference#directives].

PlaybackFinished request

Sent when the stream Alexa is playing comes to an end on its own. If your skill explicitly stops the playback with the Stop directive, Alexa sends PlaybackStopped instead of PlaybackFinished.

Example request

{ "version": "1.0", "context": { "System": { "application": {}, "user": {}, "device": {} } }, "request": { "type": "AudioPlayer.PlaybackFinished", "requestId": "unique.id.for.the.request", "timestamp": "timestamp of request in format: 2018-04-11T15:15:25Z", "token": "token representing the currently playing stream", "offsetInMilliseconds": 0, "locale": "a locale code such as en-US" } } 

Request parameters

Response

Your skill can respond to PlaybackFinished with a Stop or ClearQueue directive.

The response cannot include:

• Any standard properties such as outputSpeech, card, or reprompt.
• Any other AudioPlayer directives.
• Any other directives from other interfaces, such a [Dialog directive][dialog-interface-reference#directives].

PlaybackStopped request

Sent when Alexa stops playing an audio stream in response to one of the following AudioPlayer directives:

• Stop
• Play with a playBehavior of REPLACE_ALL.
• ClearQueue with a clearBehavior of CLEAR_ALL.

This request is also sent if the user makes a voice request to Alexa, since this temporarily pauses the playback. In this case, the playback begins automatically once the voice interaction is complete. If playback stops because the audio stream comes to an end on its own, Alexa sends PlaybackFinished instead of PlaybackStopped.

Example request

{ "version": "1.0", "context": { "System": { "application": {}, "user": {}, "device": {} } }, "request": { "type": "AudioPlayer.PlaybackStopped", "requestId": "unique.id.for.the.request", "timestamp": "timestamp of request in format: 2018-04-11T15:15:25Z", "token": "token representing the currently playing stream", "offsetInMilliseconds": 0, "locale": "a locale code such as en-US" } } 

Request parameters

Response

Your skill can't return a response to PlaybackStopped.

PlaybackNearlyFinished request

Sent when the device is ready to add the next stream to the queue.

To progress through a playlist of audio streams, respond to this request with a Play directive for the next stream and set playBehavior to ENQUEUE or REPLACE_ENQUEUED. This adds the new stream to the queue without stopping the current playback. Alexa begins streaming the new audio item once the currently playing track finishes.

Example request

{ "version": "1.0", "context": { "System": { "application": {}, "user": {}, "device": {} } }, "request": { "type": "AudioPlayer.PlaybackNearlyFinished", "requestId": "unique.id.for.the.request", "timestamp": "timestamp of request in format: 2018-04-11T15:15:25Z", "token": "token representing the currently playing stream", "offsetInMilliseconds": 0, "locale": "a locale code such as en-US" } } 

Request parameters

Response

Your skill can respond to PlaybackNearlyFinished with any AudioPlayer directive.

The response cannot include:

• Any standard properties such as outputSpeech, card, or reprompt.
• Any other directives from other interfaces, such a [Dialog directive][dialog-interface-reference#directives].

PlaybackFailed request

Sent when Alexa encounters an error when attempting to play a stream.

This request type includes two token properties – one as a property of the request object, and one as a property of the currentPlaybackState object. The request.token property represents the stream that failed to play. The currentPlaybackState.token property can be different if Alexa is playing a stream and the error occurs when attempting to buffer the next stream on the queue. In this case, currentPlaybackState.token represents the stream that was successfully playing.

Example request

{ "version": "1.0", "context": { "System": { "application": {}, "user": {}, "device": {} } }, "request": { "type": "AudioPlayer.PlaybackFailed", "requestId": "unique.id.for.the.request", "timestamp": "timestamp of request in format: 2018-04-11T15:15:25Z", "token": "token representing the currently playing stream", "offsetInMilliseconds": 0, "locale": "a locale code such as en-US", "error": { "type": "error code", "message": "description of the error that occurred" }, "currentPlaybackState": { "token": "token representing stream playing when error occurred", "offsetInMilliseconds": 0, "playerActivity": "player state when error occurred, such as PLAYING" } } } 

Request parameters

Response

Your skill can respond to PlaybackFailed with any AudioPlayer directive.

The response cannot include:

• Any standard properties such as outputSpeech, card, or reprompt.
• Any other directives from other interfaces, such a [Dialog directive][dialog-interface-reference#directives].

System.ExceptionEncountered request

If a response to an AudioPlayer request causes an error, Alexa sends your skill a System.ExceptionEncountered request. Alexa ignores any directives included in the response to this request.

Example request

{ "type": "System.ExceptionEncountered", "requestId": "unique.id.for.the.request", "timestamp": "timestamp of request in format: 2018-04-11T15:15:25Z", "locale": "a locale code such as en-US", "error": { "type": "error code such as INVALID_RESPONSE", "message": "description of the error that occurred" }, "cause": { "requestId": "unique identifier for the request that caused the error" } } 

Request parameters

Response

Your skill can't return a response to System.ExceptionEncountered request.

Related topics

• Request and Response JSON Reference
• Request Types Reference
• PlaybackController Interface Reference

Last updated: Sep 06, 2024