symbl-chime-adapter

Symbl's realtime websockets adapter for Amazon Chime.

Set Up for Symbl

Install symbl-chime-adapter

To get started you will need to add the symbl-chime-adapter to your node dependencies.

npm install --save symbl-chime-adapter

Symbl Credentials

Create an account in the Symbl Console if you have not done so already.

After you login, you will find your appId and appSecret on the home page.

Create a .env file in demos/browser and demos/serverless/src that includes your appId and appSecret as shown below.

SYMBL_APP_ID=<xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
SYMBL_APP_SECRET=<xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>

The App ID and App Secret are used to authenticate your session with Symbl by generating an access token.

Your App ID and Secret should not be shared or posted publicly.

Initialization

The Symbl adapter should be initialized after connecting to your Chime video conference.

To connect each Chime participant to Symbl, it is best practice to generate the client’s access token on your backend service.

After the token is generated it can be returned along with the chime meeting configuration as shown below. For a full example of this, please see this page of our chime demo application.

const res = await fetch(`https://api.symbl.ai/oauth2/token:generate`, {
      method: 'POST',
      mode: 'cors',
      cache: 'no-cache',
      credentials: 'same-origin',
      headers: {
        'Content-Type': 'application/json',
      },
      redirect: 'follow',
      referrerPolicy: 'no-referrer',
      body: JSON.stringify({
        type: 'application',
        appId: symblAppId,
        appSecret: symblAppSecret,
      }),
    });
    accessToken = await res.json();
    
    return response(200, 'application/json', JSON.stringify({
    JoinInfo: {
      Meeting: meeting,
      Attendee: attendee,
      Symbl: accessToken,
    },
  }, null, 2));
};

After the token is generated and returned by your server, the Symbl Access Token can be applied by setting the static property ACCESS_TOKEN of the Symbl class.

Symbl.ACCESS_TOKEN = joinInfo.Symbl.accessToken;

After the access token has been set and your client has joined the Chime meeting, you can instantiate the Symbl class.

The Symbl constructor takes two parameters:

chime

Field	Type	Description
attendeeId	string	Attendee unique identifier
userName	string	Attendee name
meetingId	string	Unique meeting identifier
meeting	string	Name of meeting

options

Field	Type	Description
confidenceThreshold	double	default: 0.5 - Minimum required confidence for insight to be recognized.
languageCode	array	Array of comma separated strings. Valid language codes en-US, en-GB, en-AU, it-IT, nl-NL, fr-FR, fr-CA, de-DE, es-US, ja-JP
insightsEnabled	boolean	default: true - True if insights should be generated for conversation.

Whether or not to generate insights.

  this.symbl = new Symbl(
      {
          attendeeId: this.configuration.credentials.attendeeId,
          userName: this.configuration.credentials.externalUserId.split('#').pop(),
          meetingId: this.configuration.credentials.meetingId,
          meeting: this.meeting,
      }, {
          confidenceThreshold: 0.5,
          languageCode: 'en-US',
          insightsEnabled: true,
      }
  );
  // subscribe to realtime event publishers (see below)
  this.symbl.start();

Subscribe to Realtime Events

Learn how to subscribe to Symbl’s conversational insights and transcription.

There are three different event types that you can subscribe through with Symbl’s Conversational AI Adapter for Chime.

• Closed Captions
• Transcripts
• Insights

Closed Captions

Realtime closed captioning is enabled by default and provides realtime transcription of your audio content. Closed captioning tracks can be added to any video element through the callback handler to your Symbl instance.

Handler

Field	Type	Description
id	string	Insight ID
text	string	Insight content
asignee	object	Assignee Object

The handler can be added using the subscribeToCaptioningEvents function of the Symbl instance.

const captioningHandler = {
    onCaptioningToggled: (ccEnabled: boolean) => {
        // Implement
    },
    onCaptionCreated: (caption: Caption) => {
        console.warn('Caption created', caption);
        // Retrieve the video element that you wish to add the subtitle tracks to.
        const activeVideoElement = getActiveVideoElement() as HTMLVideoElement;
        if (activeVideoElement) {
            caption.setVideoElement(activeVideoElement);
        }
    },
    onCaptionUpdated: (caption: Caption) => {
        const activeVideoElement = getActiveVideoElement() as HTMLVideoElement;
        
        caption.setVideoElement(activeVideoElement);
    },
};
symbl.subscribeToCaptioningEvents(captioningHandler);

Setting the video element that subtitles will be superimposed over should be done by calling the setVideoElement function on the Caption class.

If your video chat application has alternating primary video tiles, this can be used to change which element is active.

Realtime Insights

Realtime insights are generated as Symbl processes the conversation in your video chat platform.

When an Insight is detected by Symbl and the onInsightCreated event is emitted, an Insight object is passed to the callback function provided in the Insight handler.

The Insight class holds data about the insight generated.

Insight Class Attributes

Field	Type	Description
id	string	Insight ID
text	string	Insight content
asignee	object	Assignee Object

Handler

The Symbl adapter exposes a handler function, subscribeToInsightEvents, that has a callback function onInsightCreated.

Insights are enabled by default, but can be manually disabled through the insightsEnabled parameter in the config of the Symbl constructor.

new Symbl(chimeConfiguration, {insightsEnabled: true});

Subscribing to the Insight publisher is achieved by passing a handler to the subscribeToInsightEvents function of your Symbl instance.

Example

When an insight event is emitted from the onInsightCreated handler, you can use the Insight object returned and either use the createElement function to create a default element or you can use the data included in the Insight object returned in the handlers callback to create your own element, capture the data and store as a metric, etc…

const insightHandler = {
    onInsightCreated: (insight: Insight) => {
    
        // Creates a predesigned insight element
        const element = insight.createElement();
        
        // Customize any styling
        element.classList.add('mx-auto');
        element.style.width = '98%';
        
        /** OR create your own element
        insight.element = document.createElement('div');
        insight.element.innerHTML = `<div style="width: auto; height: 400px">
                                 <h3 style="font-width: 400;">
                                     ${insight.type}
                                 </h3>
                                 <br>
                                 <h2>
                                     ${insight.text}
                                 </h2>
                              </div>`;          
        **/
        
        // Retrieve container you wish to add insights to.
        const insightContainer = document.getElementById('receive-insight');
        
        // Call add on the insight object to add it to DIV
        insight.add(insightContainer);
    }
};
// Subscribe to realtime insight events using the handler created above
this.symbl.subscribeToInsightEvents(insightHandler);

Realtime Transcripts

Realtime transcripts differ slightly from realtime closed-captioning. A Transcript object is created when after speech is no longer detected.

Attributes

Field	Type	Description
message	string	Speech content
userName	string	Speaker Name
userId	string	Speaker Id
timestamp	Date	Time of the transcript event

Handler

The Transcript handler has only one event, onTranscriptCreated. Each time a speaker finishes speaking a Transcript object is generated.

Subscribing to the transcript publisher is achieved by passing a handler to the subscribeToTranscriptEvents function of your Symblinstance.

Example

const transcriptHandler = {
    onTranscriptCreated: (transcript: Transcript) => {
      // Handle transcript item
    }
};
this.symbl.subscribeToTranscriptEvents(transcriptHandler);

Generating Meeting Summary URL

To generate a meeting summary URL, you need only to call the getSummaryUrlfunction of your Symbl instance.

const meetingSummaryUrl = await symbl.getSummaryUrl();