ValidationError when Registering Subscription with Microsoft Graph API

Question

I am encountering a ValidationError when trying to register a subscription using the Microsoft Graph API. Below are the details of my request and the error message received:

Request:

{ 
  "changeType": "updated",
  "notificationUrl": "[my_url]",
  "resource": "sites/[my_site_id]/lists/[my_list_id]",
  "expirationDateTime": "2024-08-09T23:59:59Z",
  "clientState": "secretClientValue"
}

Error Response:

{  
  "type": "json",   
  "body": 
		{ "error": {   
			"code": "ValidationError",   
			"message": "{}",   
			"innerError": {      
				"date": "2024-08-07T03:45:50",   
				"request-id": "51747659-1766-45c6-aec2-c621ae390cc7",   
				"client-request-id": "51747659-1766-45c6-aec2-c621ae390cc7"  
		 	} 
		} 
	}, 
	"status": "failed"
}

I consider that the "message" field should include a detailed description when it is an error. Could you please assist in identifying the root cause of this validation error and provide guidance on how to resolve it?

Answer 1

The validation error suggests that your notification URL is not able to respond to an endpoint validation request send by Microsoft.

Your notification endpoint should have provision for reading the validation token from the query parameters and return it back immediately.

Follow this link for more information:

https://learn.microsoft.com/en-us/graph/api/subscription-post-subscriptions?view=graph-rest-1.0&tabs=http#notification-endpoint-validation

To know how a sample notification endpoint handles this validation request, refer to the link below

https://github.com/microsoftgraph/aspnetcore-webhooks-sample/blob/main/src/GraphWebhooks/Controllers/ListenController.cs

Code from line 67 - 69 handles the validation request

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