Ah, I see the issue now. Let me walk you through the complete, working setup: 1. First, verify your Slack webhook block is correctly set up:

python
from prefect.blocks.notifications import SlackWebhook

# Test the block directly
slack_webhook = SlackWebhook.load("slack-notifications")
slack_webhook.notify("Test message")  # This should send a message to your Slack channel

2. For the automation setup in the UI, here are the exact steps that should work: a. Go to the Automations page in the Prefect UI b. Click "Create Automation" c. Set up the trigger: - Select "Flow run state update" as the trigger type - Choose the state you want to monitor (e.g., "Failed") - Optionally add any flow name filters d. Set up the action: - Select "Send a notification" as the action type - Choose your "slack-notifications" block - In the message body, use this template:

Flow: {{ flow.name }}
State: {{ flow_run.state.name }}
Message: {{ flow_run.state.message }}
Time: {{ flow_run.state.timestamp }}

3. Create a test flow to verify:

python
from prefect import flow

@flow
def test_notifications():
    raise Exception("Testing notifications")

if __name__ == "__main__":
    test_notifications()

If this still isn't working, let's troubleshoot: 1. What version of Prefect are you running? (

prefect version

) 2. Are you using Prefect Cloud or self-hosted? 3. When you run the test code to send a message directly via the block (step 1 above), does it work? 4. In the UI, after setting up the automation, does it show as "Active"? 5. When you run a flow that should trigger the automation, do you see any errors in the Prefect logs? The most common issues are: - Incorrect webhook URL in the block - Automation not properly activated - Missing permissions in the Slack app configuration - Network connectivity issues between Prefect and Slack Let me know which of these tests work and which don't, and we can narrow down the problem.

Yes, you'll need specific NSG rules! Here's what you need to know: 1. Required NSG Rules: - Allow outbound HTTPS (port 443) to Slack's webhook domains: -

<http://hooks.slack.com|hooks.slack.com>

-

*.<http://hooks.slack.com|hooks.slack.com>

- The IP ranges can be found in Slack's IP ranges documentation 2. Logging and Troubleshooting: You can check several places for failure logs: a. Prefect logs:

bash
   prefect logs -f "flow-run/YOUR_FLOW_RUN_ID"

b. Enable debug logging in your Prefect deployment:

python
   import logging
   from prefect import flow

   logging.basicConfig(level=logging.DEBUG)

   @flow(log_prints=True)
   def your_flow():
       ...

c. Test connectivity directly:

python
   import requests
   import logging

   logging.basicConfig(level=logging.DEBUG)
   
   # This will show detailed HTTP request/response info
   logging.getLogger('urllib3').setLevel(logging.DEBUG)

   webhook_url = "your_slack_webhook_url"
   response = <http://requests.post|requests.post>(webhook_url, json={"text": "Test message"})
   print(f"Status Code: {response.status_code}")
   print(f"Response: {response.text}")

3. Quick Verification Steps: 1. First, verify basic connectivity:

bash
      # Test if you can reach Slack's webhook domain
      curl -v <https://hooks.slack.com>

2. Check if your Prefect worker has internet access:

python
      from prefect import flow
      import requests

      @flow
      def test_connectivity():
          try:
              response = requests.get("<https://hooks.slack.com>")
              print(f"Status code: {response.status_code}")
          except Exception as e:
              print(f"Connection failed: {e}")

      test_connectivity()

4. Common VNet Issues: - Missing DNS resolution for

<http://hooks.slack.com|hooks.slack.com>

- Outbound traffic blocked by default NSG rules - Proxy requirements in your environment - Missing route table entries for internet access If you're still having issues after adding the NSG rules, we can dig deeper into the logs. Let me know what you find when you check the connectivity and logs.

Ah, this is because the

notify

method is asynchronous in Prefect 3.x. You need to either use

await

in an async function or use the sync version. Here's both approaches: Async Version (preferred):

python
from prefect.blocks.notifications import SlackWebhook
import asyncio

async def test_slack():
    try:
        slack_webhook = await SlackWebhook.load("slack-notifications")
        await slack_webhook.notify("Test message")
        print("✅ Notification sent successfully!")
    except Exception as e:
        print(f"❌ Failed to send test Slack notification: {e}")

# Run the async function
asyncio.run(test_slack())

Sync Version (if you need to use it in a synchronous context):

python
from prefect.blocks.notifications import SlackWebhook
from prefect.utilities.asyncutils import sync_compatible

try:
    slack_webhook = SlackWebhook.load("slack-notifications")
    slack_webhook.notify_sync("Test message")  # Note the _sync suffix
    print("✅ Notification sent successfully!")
except Exception as e:
    print(f"❌ Failed to send test Slack notification: {e}")

The error you're seeing is because you're trying to call the async

notify

method without awaiting it. Choose either of the above approaches based on your context. The async version is generally preferred in Prefect 3.x, but both will work. If you're testing this inside a flow, you can use the async version like this:

python
from prefect import flow
from prefect.blocks.notifications import SlackWebhook

@flow
async def test_flow():
    try:
        slack_webhook = await SlackWebhook.load("slack-notifications")
        await slack_webhook.notify("Test message from flow")
        print("✅ Notification sent successfully!")
    except Exception as e:
        print(f"❌ Failed to send test Slack notification: {e}")

if __name__ == "__main__":
    asyncio.run(test_flow())