Use autoscale actions to send email and webhook alert notifications in Azure Monitor

This article shows you how set up triggers so that you can call specific web URLs or send emails based on autoscale actions in Azure.


Webhooks allow you to route the Azure alert notifications to other systems for post-processing or custom notifications. For example, routing the alert to services that can handle an incoming web request to send SMS, log bugs, notify a team using chat or messaging services, etc. The webhook URI must be a valid HTTP or HTTPS endpoint.


Email can be sent to any valid email address. Administrators and co-administrators of the subscription where the rule is running will also be notified.

Cloud Services and Web Apps

You can opt-in from the Azure portal for Cloud Services and Server Farms (Web Apps).

  • Choose the scale by metric.

scale by

Virtual Machine scale sets

For newer Virtual Machines created with Resource Manager (Virtual Machine scale sets), you can configure this using REST API, Resource Manager templates, PowerShell, and CLI. A portal interface is not yet available. When using the REST API or Resource Manager template, include the notifications element with the following options.

"notifications": [
        "operation": "Scale",
        "email": {
          "sendToSubscriptionAdministrator": false,
          "sendToSubscriptionCoAdministrators": false,
          "customEmails": [
        "webhooks": [
            "serviceUri": "",
            "properties": {
              "optional_key1": "optional_value1",
              "optional_key2": "optional_value2"
Field Mandatory? Description
operation yes value must be "Scale"
sendToSubscriptionAdministrator yes value must be "true" or "false"
sendToSubscriptionCoAdministrators yes value must be "true" or "false"
customEmails yes value can be null [] or string array of emails
webhooks yes value can be null or valid Uri
serviceUri yes a valid https Uri
properties yes value must be empty {} or can contain key-value pairs

Authentication in webhooks

The webhook can authenticate using token-based authentication, where you save the webhook URI with a token ID as a query parameter. For example, https://mysamplealert/webcallback?tokenid=sometokenid&someparameter=somevalue

Autoscale notification webhook payload schema

When the autoscale notification is generated, the following metadata is included in the webhook payload:

        "version": "1.0",
        "status": "Activated",
        "operation": "Scale In",
        "context": {
                "timestamp": "2016-03-11T07:31:04.5834118Z",
                "id": "/subscriptions/s1/resourceGroups/rg1/providers/microsoft.insights/autoscalesettings/myautoscaleSetting",
                "name": "myautoscaleSetting",
                "details": "Autoscale successfully started scale operation for resource 'MyCSRole' from capacity '3' to capacity '2'",
                "subscriptionId": "s1",
                "resourceGroupName": "rg1",
                "resourceName": "MyCSRole",
                "resourceType": "microsoft.classiccompute/domainnames/slots/roles",
                "resourceId": "/subscriptions/s1/resourceGroups/rg1/providers/microsoft.classicCompute/domainNames/myCloudService/slots/Production/roles/MyCSRole",
                "portalLink": "",
                "oldCapacity": "3",
                "newCapacity": "2"
        "properties": {
                "key1": "value1",
                "key2": "value2"
Field Mandatory? Description
status yes The status that indicates that an autoscale action was generated
operation yes For an increase of instances, it will be "Scale Out" and for a decrease in instances, it will be "Scale In"
context yes The autoscale action context
timestamp yes Time stamp when the autoscale action was triggered
id Yes Resource Manager ID of the autoscale setting
name Yes The name of the autoscale setting
details Yes Explanation of the action that the autoscale service took and the change in the instance count
subscriptionId Yes Subscription ID of the target resource that is being scaled
resourceGroupName Yes Resource Group name of the target resource that is being scaled
resourceName Yes Name of the target resource that is being scaled
resourceType Yes The three supported values: "microsoft.classiccompute/domainnames/slots/roles" - Cloud Service roles, "microsoft.compute/virtualmachinescalesets" - Virtual Machine Scale Sets, and "Microsoft.Web/serverfarms" - Web App
resourceId Yes Resource Manager ID of the target resource that is being scaled
portalLink Yes Azure portal link to the summary page of the target resource
oldCapacity Yes The current (old) instance count when Autoscale took a scale action
newCapacity Yes The new instance count that Autoscale scaled the resource to
Properties No Optional. Set of <Key, Value> pairs (for example, Dictionary <String, String>). The properties field is optional. In a custom user interface or Logic app based workflow, you can enter keys and values that can be passed using the payload. An alternate way to pass custom properties back to the outgoing webhook call is to use the webhook URI itself (as query parameters)