How to use CAP Alert App

Some Emergency Alert System or Emergency Mass Notification System(like Everbridge, Alertus) can push CAP(Common Alerting Protocol) messages to the targets including digital signage when there is an emergency. You can integrate with these systems using CAP Alert app with OptiSigns. 

Using OptiSigns' CAP Alert app, you can generate a webhook and integrate with the Emergency Alert System. When there is an emergency, the emergency alert system can call the webhook to send the CAP message and trigger the CAP alert app. The CAP alert will take over the target screens and display the emergency message. The screen will resume and play the original content when the emergency is over. 




Let's jump in and get started:

First, you will need to have your screens set up and paired. For more information on how to do that, click here.

Then log on to our portal:

Go to Files/Assets, Click on "App"

Select "CAP Alert" app:
Set up your CAP alert app:
  • Name: Name of your assets, this will not be displayed on the screens.
  • Target: Select Screens or Tags.
  • Screens/Tags: Select which screens or group of screens (tags) you want to target for this emergency situation. (i.e. Fire in building/location 1)
  • Content Type: Select "Post to Webhook" if you would like to post the CAP message to your signage, the app also support RSS feed.
  • Webhook: The app will generate a webhook URL after it is saved. This is what you should share with the emergency alert system.
  • Display Type: Currently the app will take over the full screen when there is an emergency
  • Status: Set the app to active or inactive.
  • Emergency Duration: How long the emergency message will take over the screen. The value can be overwritten by the webhook call.

Advanced settings:


  • Using Text Font, Color, Background Color, Text Alignment and Background Image, you can design the message as you desire (i.e. text showed up in the middle of the screen on top of your organization branded image template)
  • Item Duration: If there are multiple items from the RSS feed, how long each item will be displayed.
  • Title Tag: Message title from the CAP message/RSS feed, default is <headline> - you can change if your feed is different
  • Description Tag: Message content from the CAP message/RSS feed, default is <description> - you can change if your feed is different
  • Location (Screen Tags): If you can match the screen tags with your location passed from CAP message/RSS feed - you can use it to control the selection of the targe screens.
  • Filter content contain: you can filter for title, description content certain words only: i.e. fire, so if title, description contain "fire" (not case sensitive), then the app will trigger screen take over.
  • Use Urgency, Severity, and Certainty to control the filter of the CAP messages, these are standard attributes of CAP message. By default, the app will be triggered on all values, if you have selected values, the app will be triggered only on the selected values. 


Click Save.
After Saving, the app will generate a webhook URL automatically and start to waiting on the webhook to be triggered, you can share the webhook URL with your emergency alert system, it can trigger the webhook when there is emergency and pass the CAP messages to take over the screens.

To test your CAP alert integration, you can use postman to post a CAP message to the webhook. Pass the CAP message to the "data", and you can set the emergency duration in the call as well.

If you have any additional questions, concerns or any feedback about OptiSigns, feel free to reach out to our support team at or just submit a ticket here.

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