Azure Blob Storage Webhook Setup Guide

Event Grid can only create system topics and subscriptions once the Microsoft.EventGrid resource provider is registered on the Azure subscription. This is a one-time setup per Azure subscription — skip it only if Event Grid is already in use there. If it is not registered, creating the subscription fails with “The subscription is not registered to use namespace ‘Microsoft.EventGrid’”.

• In the Azure portal, search for and open Subscriptions, then select the subscription that contains your storage account.
• In the left menu, go to Settings > Resource providers.
• Search for Microsoft.EventGrid, select it, and click Register (wait until Status shows Registered, ~1–2 minutes).
• Alternatively via Azure CLI: az provider register --namespace Microsoft.EventGrid
• Registering a resource provider requires Contributor or Owner on the Azure subscription — a subscription admin may need to do this step.

Before configuring the Event Grid subscription, copy the Native Webhook URL from this connection.

• The URL is shown in the Native Webhook URL field on the connection settings page — it is only available after the connection has been created.
• Copy the full URL and keep it ready for the next step.

Open the Azure portal and navigate to your storage account.

• In the left sidebar, click Events.
• If no system topic exists yet, Azure creates one automatically when you add the first subscription.
• Note: your storage account must be in a region that supports Event Grid (most regions do).

In the Events blade of your storage account, click + Event Subscription.

• Name: Enter a descriptive name (e.g., stackone-webhook).
• Event Schema: Leave as Event Grid Schema.
• Filter to Event Types: Select the event types you want to receive (e.g., Blob Created, Blob Deleted). You can select multiple.
• Endpoint Type: Select Web Hook.
• Endpoint: Paste the Native Webhook URL you copied in step 1.
• Additional Features: Leave Max events per batch at its default (1). Batched delivery is not supported — only the first event in a batched request is processed.
• Click Create.

Azure Event Grid immediately sends a validation request to the endpoint when the subscription is created.

• StackOne automatically responds to the handshake with the required validationResponse — no action is needed from you.
• If creation reports endpoint validation failure, verify the Native Webhook URL is correct and the connection is active.

Trigger a blob operation (upload or delete a file) in the storage account and confirm the event reaches your downstream consumer.

• Azure Event Grid retries failed deliveries with exponential backoff for up to 24 hours by default.
• Delivery status is visible in the Azure portal under the Event Grid subscription’s Metrics and Dead-letter blades.

These events are available on all Azure Blob Storage accounts.

• Blob Created (Microsoft.Storage.BlobCreated) — Fired when a blob is successfully created or replaced (PutBlob, CopyBlob, PutBlockList, FlushWithClose)
• Blob Deleted (Microsoft.Storage.BlobDeleted) — Fired when a blob is deleted (DeleteBlob, DeleteFile)
• Blob Tier Changed (Microsoft.Storage.BlobTierChanged) — Fired when a block blob’s access tier changes (SetBlobTier)
• Async Operation Initiated (Microsoft.Storage.AsyncOperationInitiated) — Fired when a blob operation is initiated and its data is still being retrieved (e.g. archive rehydration start)

These events are only available on storage accounts with hierarchical namespace enabled (Azure Data Lake Storage Gen2).

• Blob Renamed (Microsoft.Storage.BlobRenamed) — Fired when a blob is renamed (RenameFile)
• Directory Created (Microsoft.Storage.DirectoryCreated) — Fired when a directory is created (CreateDirectory)
• Directory Renamed (Microsoft.Storage.DirectoryRenamed) — Fired when a directory is renamed (RenameDirectory)
• Directory Deleted (Microsoft.Storage.DirectoryDeleted) — Fired when a directory is deleted (DeleteDirectory)

These events fire when an account-scheduled policy run completes. They run on Azure’s daily schedule and cannot be triggered on demand.

• Blob Inventory Policy Completed (Microsoft.Storage.BlobInventoryPolicyCompleted) — Fired when a blob inventory policy run completes
• Lifecycle Policy Completed (Microsoft.Storage.LifecyclePolicyCompleted) — Fired when a lifecycle management policy run completes

Azure Event Grid delivers events as an HTTP POST with a JSON array body. Each array element is an event envelope with fields id (GUID), eventType, subject, eventTime, topic, dataVersion, metadataVersion, and data (the blob-specific payload). Event Grid delivers one event per request by default — do not enable batched delivery (Max events per batch must remain 1), as only the first event in each request is processed.

Azure Event Grid (Event Grid Schema) does not include HMAC signature headers. Deliveries are authenticated solely by endpoint URL secrecy.