Missing webhook events

Question

Missing webhook events

Jacques Viviers 0

1.We create a subscription for our Tenant in our application. (This works)
2.After subscription is created, we receive webhook validation and subscription is visible.
3.Subscription is active and there are events available, however they are not sent to subscription - we don't receive any webhooks for created subscription.

Rakesh Mishra 3,870 Reputation points Microsoft External Staff Moderator

2025-12-08T15:37:07.0966667+00:00
Hi @Jacques Viviers ,

Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.

Please check below and share your findings.

Verify the Event Grid subscription validation (handshake) — when a webhook subscription is created Event Grid sends a SubscriptionValidationEvent (or uses CloudEvents validation). If your endpoint doesn't respond with the required validation response the subscription will appear, but no events will be delivered.

Confirm the webhook endpoint is reachable from Event Grid (public access / network) — Event Grid must be able to reach your endpoint. If your APIM instance or webhook is internal-only (private VNet) or behind a gateway that blocks Event Grid, deliveries will fail. The subscription validation doc explicitly calls out App Gateway/WAF rules as a common cause. If your endpoint is private, expose or enable a reachable endpoint for validation/delivery.

Validate APIM → Event Grid configuration and event filters — if you enabled API Management as an Event Grid source, ensure the subscription scope/filters match the events you expect and that APIM is actually publishing the events

Reference:

https://learn.microsoft.com/en-us/azure/event-grid/troubleshoot-subscription-validation

https://learn.microsoft.com/en-us/azure/event-grid/event-schema-api-management?tabs=cloud-event-schema

If you still don’t see any webhook events being delivered after these checks, you might need to gather more details to dive deeper into the issue.

What event types did you choose for your subscription?

Have you confirmed that the webhook endpoint is correctly set up and can receive events?

Are there any logs or error messages on the receiving service that might indicate why events aren't arriving?

Are there any additional filters or permissions that might be affecting the webhook delivery?

3 answers

Your answer

Rakesh Mishra 3,870 Reputation points Microsoft External Staff Moderator

2025-12-08T15:37:07.0966667+00:00

Hi @Jacques Viviers ,

Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.

Please check below and share your findings.

Verify the Event Grid subscription validation (handshake) — when a webhook subscription is created Event Grid sends a SubscriptionValidationEvent (or uses CloudEvents validation). If your endpoint doesn't respond with the required validation response the subscription will appear, but no events will be delivered.

Confirm the webhook endpoint is reachable from Event Grid (public access / network) — Event Grid must be able to reach your endpoint. If your APIM instance or webhook is internal-only (private VNet) or behind a gateway that blocks Event Grid, deliveries will fail. The subscription validation doc explicitly calls out App Gateway/WAF rules as a common cause. If your endpoint is private, expose or enable a reachable endpoint for validation/delivery.

Validate APIM → Event Grid configuration and event filters — if you enabled API Management as an Event Grid source, ensure the subscription scope/filters match the events you expect and that APIM is actually publishing the events

Reference:

https://learn.microsoft.com/en-us/azure/event-grid/troubleshoot-subscription-validation

https://learn.microsoft.com/en-us/azure/event-grid/event-schema-api-management?tabs=cloud-event-schema

If you still don’t see any webhook events being delivered after these checks, you might need to gather more details to dive deeper into the issue.

What event types did you choose for your subscription?

Have you confirmed that the webhook endpoint is correctly set up and can receive events?

Are there any logs or error messages on the receiving service that might indicate why events aren't arriving?

Are there any additional filters or permissions that might be affecting the webhook delivery?

Answer 1

Jacques Viviers 0

We have checked the Azure App Gateway, but no logs for any blocked events.

Answer 2

Deleted

This answer has been deleted due to a violation of our Code of Conduct. The answer was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.

Comments have been turned off. Learn more

Answer 3

I’ve run into this with a couple of time, and the strange part is it always looks like the subscription is healthy even though nothing actually gets delivered.

In our cases the webhook endpoint wasn’t passing APIM’s reachability or validation checks, so Event Grid simply stopped sending events without showing any obvious errors.

The two biggest things to double-check are the webhook URL and how it responds.

Kindly, make sure the endpoint can return a quick 200 response with no extra authentication during the initial validation. I’ve seen teams protect the endpoint too early with headers or gateway rules, and APIM just refuses to deliver anything. Even App Gateway didn’t show logs in one of our situations, so the lack of logs isn’t unusual.

Once the webhook endpoint was reachable from the internet and responded cleanly, the events immediately started flowing. In short, the subscription is fine. It’s almost always the webhook URL not passing the initial validation or getting blocked somewhere in front of it.

Share via

Missing webhook events

3 answers

Your answer