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Creating a Webhook for Slack

What do you want your webhook to do?​

Scenario:
As a Data Request Manager, you currently receive daily email summaries when DSAR requests are email-verified. These emails are often delayed and mixed with other messages, making it hard to act promptly. You want to be notified immediately via Slack, when all action items on a DSAR are complete so you can review the request right away.

Solution:
Use a Webhook to Send Slack Notifications When DSAR Action Items Are Complete

To set this up, you’ll need to create a Slack app and configure a webhook. Start by reviewing the Slack Webhooks documentation.

Step 1: Create Slack App​

First you need to create a Slack app that will host the messages sent from Osano. Click the Create an app button within the Slack webhooks documentation page.

Step 1

Step 2: Choose How to Create Your App​

Select From scratch to build a new app.

Step 2

Step 3: Name Your App & Select a Workspace​

Give your app a name and choose the Slack workspace where notifications should be sent. Then click Create App.

Step 3

Step 4: Add Incoming Webhooks​

In the app’s Features tab, click Incoming Webhooks and toggle the switch to On to activate incoming webhooks.

Step 4

Step 5: Add App to Workspace​

Click the Add New Webhook button to create a new webhook. Install the app if prompted. Once the app has been installed, there should be a new entry with a Webhook URL. Click the Copy button next to the webhook url as we'll need this later.

Step 5 Step 6

Step 6: Create Webhook in Osano​

Navigate to the Webhooks section on my.osano.com and create a new webhook.

App and Event​

Under the App and Event section, select Subject Rights as the product and Action Items Completed as the event.

Actions​

For the method and url, select POST and enter your Slack webhook url from Step 5

  • Method: POST
  • URL: <YOUR_SLACK_WEBHOOK_URL>

Content​

Slack requires a specific JSON structure for messages. Below is a sample payload using Slack’s https://docs.slack.dev/block-kit/ format. You can customize it further using supported variables listed on the variables page.

{
    "blocks": [
        {
            "type": "header",
            "text": {
                "type": "plain_text",
                "text": "All Action Items Complete",
                "emoji": true
            }
        },
        {
            "type": "section",
            "fields": [
                {
                    "type": "mrkdwn",
                    "text": "*Request Type:*\n{{dsaRequestType}}"
                },
                {
                    "type": "mrkdwn",
                    "text": "*Request ID:*\n{{dsarId}}"
                }
            ]
        },
        {
            "type": "divider"
        },
        {
            "type": "context",
            "elements": [
                {
                    "type": "mrkdwn",
                    "text": "Please review and take appropriate action."
                }
            ]
        }
    ]
}

Handling missing variables in Block Kit​

Slack's Block Kit validates every field in the payload. Required text fields such as the text property in header and section blocks must contain at least one character — Slack will reject the entire message with an invalid_payload or invalid_blocks error if any of these fields resolve to null or an empty string.

Because Osano replaces unresolved template variables with null or removes them (see Functions — Unresolved Variables), a Block Kit payload that places a variable as the sole content of a required text field could fail delivery if that variable is missing at runtime.

To avoid this, use the coalesce or pipe fallback syntax (see Functions — Default / Fallback Values) for any variable used inside a Block Kit text field:

{
    "type": "mrkdwn",
    "text": "*Request Type:*\n{{dsaRequestType | 'N/A'}}"
}

This ensures the field always contains a valid string, even when the variable is unavailable.

Result: Real-Time Notifications for DSAR​

Now click the Test button in the content section to verify your webhook sends a message to the channel you selected.

Result