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:
event_source_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.