Send Slack Notifications Using Google Tag Manager Server Container

Oct 24, 2022
Jun 1, 2021
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We created a tag for the Google Tag Manager server container that sends a notification to Slack. With the help of this tag, you can send any information about user actions on your site to the Slack channel. This tag allows adding variables, such as product and user information, inside the notification. You can notify your team about a new purchase, abandoned cart, or a new quote request from clients. One of the use cases of this tag is to send notifications to the sales team Slack channel about new orders immediately. You can also use this tag to monitor your site stability.

How does the Slack tag for the Google Tag Manager Server container work?

To send Slack notifications, you will need to have a configured Google Tag Manager Server container with the user and event data you want to send inside the Slack message. You will also need to create a Slack app and generate a webhook URL for this app. It may sound complicated, but everything can be set up in a few clicks. I will cover all steps in this how-to, including creating a Slack app and webhook URL. 

Using Slack tag to test if Facebook tracking is blocked by iOS 14

One of the non-standard use cases of the Slack tag is to verify whether Facebook conversion tracking was blocked for iOS 14 users who opted out of tracking. Let’s say you’ve implemented Facebook conversion API, and you’re using a custom subdomain for the tagging server. It means that you can see events in the test events tool inside the Facebook business manager. But how can you verify that Facebook conversion tracking works for iOS 14 users who opted out of tracking?

You can set up Slack Tags that will use the same trigger as your Facebook CAPI. Open your FB ad on the iPhone that opted out of Facebook tracking, click on the ad, and test events. If tracking works, you will see Slack notifications. Since Slack and Facebook use the same triggers, you can say that Facebook tracking works too.  

How to send Slack notifications using the Google Tag Manager server container

2. Open Server container and add Slack tag from the template gallery or by clicking this link.

slack tag in server container

3. In this example, I will show how to send a Slack notification on a successful purchase. First of all, you need to make sure that the Server container has the required purchase information. If not, you will need to configure it. 

Let me show you how to send data from the web to the server container. I have a data layer inside the Web container with order information. I will use the GA4 tag to send data from the web to the server container. Inside the Web container, I’ve set up a GA4 Configuration tag with the configured transport URL that sends requests to my tagging server URL. I also set up a GA4 Purchase Event with purchase details.

ga4 tag configuration
ga4 event

4. Inside the Server container, I’ve added a GA4 Client and GA4 tag that triggers every time a GA4 client is claimed. 

client configuration in ga4
ga4 tag configuration

5. Open the preview mode of the Web and Server container and check if the Server container sees order data.

web and server container

6. Create variables inside the Server container that will take event data. Variable type Event Data -> Add Key Path -> Click Save. We will use these variables for the Slack notification. 

server container variables

7. Go to the Tags tab inside the Server container -> Click New -> Tag type Slack Notification.

8. We need to create a Slack App and then generate a Webhook for it. Click this link -> Click Create An App -> Select From scratch -> Name your app and select Slack Workspace.

slack api
slack api from scratch
slack api name app

9. Generate an incoming webhook for the app that we’ve recently created. Click Incoming Webhook -> Click the Activate Incoming Webhooks toggle to switch it on -> Scroll down and click Add New Webhook to Workspace -> Select channel you want to send notifications to and click Allow -> Copy the Webhook URL.

slack api incoming webhooks
slack add new webhook to workspace
slack tag test 

10. Paste Webhook URL into the Slack Tag.

webhook url copy
webhook url

11. Create a Slack notification text. You can add variables here. Add a trigger and click save. 

slack notification text
slack trigger configuration

12. Open the preview mode of the Web and Server containers and test if notification works.

slack tag web and server

13. Publish web and server containers.


The developers and enterprises are continuously looking for new solutions to facilitate their workflow with Slack better. I hope this post will help you set up Slack notifications for the critical events on your site.

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