Why Add Event Source URL?
Meta recently began flagging or blocking Conversion API events from sites dealing with sensitive topics—like health, political, or social issues—unless the required parameter 'Event Source URL' is included.
Without it, Meta warns sites they’re “in a category with restrictions” and will eventually cease processing their events. Adding 'Event Source URL' is now mandatory for businesses in a category with restrictions.
Benefits of Including Event Source URL
Continued use of Meta Conversions API – prevents event blocks
Compliant with Meta’s health/social/political updates
Clear source attribution — ensures Meta knows which domain events are coming from
Implementation Guide
1. Identify your Root URL
This is your full website root URL.
(example)
https://www.cometly.com
2. Map Event Source URL field
Cometly Webhooks
In the mapping section of your Event setup, click Add field and select Event Source URL:
In the Fixed Value field enter your root domain (e.g., “https://www.cometly.com”) and then click save.
After you have the Event Source URL mapped, click Save & Continue.
Zapier
Enter in your site URL in the Event Source URL field.
Field: Event Source URL
Value: your root domain (e.g., “https://www.cometly.com”)
API
When using the Cometly API, include the following fields in your payload:
Key:
urlValue: your root domain (e.g., “https://www.cometly.com”)
3. Test & Verify
Push a test event containing 'Event Source URL'
Check Meta's Events Manager or Debug API; ensure no warnings appear.
Confirm that conversion events are processed normally—no blocking.
4. Best Practices & Troubleshooting
Advice | Why It Matters |
Use the exact root domain consistently | Avoid mismatches like |
Monitor Meta Alerts | If pixel is flagged, Events Manager will list affected domains |
Consider custom event naming | Avoid sensitive keywords in event names to reduce flag risks |
Implement server-side CAPI | Strengthens event delivery and alignment with Meta’s guidelines |
If you have any questions, please contact Cometly Support by clicking the chat icon in the bottom right of your screen or email support@cometly.com.