--- title: Event notifications description: Send messages to Cloudflare Queues when objects in your R2 bucket change. image: https://developers.cloudflare.com/dev-products-preview.png --- > Documentation Index > Fetch the complete documentation index at: https://developers.cloudflare.com/r2/llms.txt > Use this file to discover all available pages before exploring further. [Skip to content](#%5Ftop) # Event notifications Event notifications send messages to your [queue](https://developers.cloudflare.com/queues/) when data in your R2 bucket changes. You can consume these messages with a [consumer Worker](https://developers.cloudflare.com/queues/reference/how-queues-works/#create-a-consumer-worker) or [pull over HTTP](https://developers.cloudflare.com/queues/configuration/pull-consumers/) from outside of Cloudflare Workers. ## Get started with event notifications ### Prerequisites Before getting started, you will need: * An existing R2 bucket. If you do not already have an existing R2 bucket, refer to [Create buckets](https://developers.cloudflare.com/r2/buckets/create-buckets/). * An existing queue. If you do not already have a queue, refer to [Create a queue](https://developers.cloudflare.com/queues/get-started/#2-create-a-queue). * A [consumer Worker](https://developers.cloudflare.com/queues/reference/how-queues-works/#create-a-consumer-worker) or [HTTP pull](https://developers.cloudflare.com/queues/configuration/pull-consumers/) enabled on your Queue. ### Enable event notifications via Dashboard 1. In the Cloudflare dashboard, go to the **R2 object storage** page. [ Go to **Overview** ](https://dash.cloudflare.com/?to=/:account/r2/overview) 2. Select the bucket you'd like to add an event notification rule to. 3. Switch to the **Settings** tab, then scroll down to the **Event notifications** card. 4. Select **Add notification** and choose the queue you'd like to receive notifications and the [type of events](https://developers.cloudflare.com/r2/buckets/event-notifications/#event-types) that will trigger them. 5. Select **Add notification**. ### Enable event notifications via Wrangler #### Set up Wrangler To begin, install [npm ↗](https://docs.npmjs.com/getting-started). Then [install Wrangler, the Developer Platform CLI](https://developers.cloudflare.com/workers/wrangler/install-and-update/). #### Enable event notifications on your R2 bucket Log in to Wrangler with the [wrangler login command](https://developers.cloudflare.com/workers/wrangler/commands/general/#login). Then add an [event notification rule](https://developers.cloudflare.com/r2/buckets/event-notifications/#event-notification-rules) to your bucket by running the [r2 bucket notification create command](https://developers.cloudflare.com/workers/wrangler/commands/r2/#r2-bucket-notification-create). Terminal window ``` npx wrangler r2 bucket notification create --event-type --queue ``` To add filtering based on `prefix` or `suffix` use the `--prefix` or `--suffix` flag, respectively. Terminal window ``` # Filter using prefix $ npx wrangler r2 bucket notification create --event-type --queue --prefix "" # Filter using suffix $ npx wrangler r2 bucket notification create --event-type --queue --suffix "" # Filter using prefix and suffix. Both the conditions will be used for filtering $ npx wrangler r2 bucket notification create --event-type --queue --prefix "" --suffix "" ``` For a more complete step-by-step example, refer to the [Log and store upload events in R2 with event notifications](https://developers.cloudflare.com/r2/tutorials/upload-logs-event-notifications/) example. ## Event notification rules Event notification rules determine the [event types](https://developers.cloudflare.com/r2/buckets/event-notifications/#event-types) that trigger notifications and optionally enable filtering based on object `prefix` and `suffix`. You can have up to 100 event notification rules per R2 bucket. ## Event types | Event type | Description | Trigger actions | | ------------- | --------------------------------------------------------------------------- | ------------------------------------------ | | object-create | Triggered when new objects are created or existing objects are overwritten. | PutObjectCopyObjectCompleteMultipartUpload | | object-delete | Triggered when an object is explicitly removed from the bucket. | DeleteObjectLifecycleDeletion | ## Message format Queue consumers receive notifications as [Messages](https://developers.cloudflare.com/queues/configuration/javascript-apis/#message). The following is an example of the body of a message that a consumer Worker will receive: ``` { "account": "3f4b7e3dcab231cbfdaa90a6a28bd548", "action": "CopyObject", "bucket": "my-bucket", "object": { "key": "my-new-object", "size": 65536, "eTag": "c846ff7a18f28c2e262116d6e8719ef0" }, "eventTime": "2024-05-24T19:36:44.379Z", "copySource": { "bucket": "my-bucket", "object": "my-original-object" } } ``` ### Properties | Property | Type | Description | | ----------------- | ------ | ------------------------------------------------------------------------------------------------------------------------------------------------ | | account | String | The Cloudflare account ID that the event is associated with. | | action | String | The type of action that triggered the event notification. Example actions include: PutObject, CopyObject, CompleteMultipartUpload, DeleteObject. | | bucket | String | The name of the bucket where the event occurred. | | object | Object | A nested object containing details about the object involved in the event. | | object.key | String | The key (or name) of the object within the bucket. | | object.size | Number | The size of the object in bytes. Note: not present for object-delete events. | | object.eTag | String | The entity tag (eTag) of the object. Note: not present for object-delete events. | | eventTime | String | The time when the action that triggered the event occurred. | | copySource | Object | A nested object containing details about the source of a copied object. Note: only present for events triggered by CopyObject. | | copySource.bucket | String | The bucket that contained the source object. | | copySource.object | String | The name of the source object. | ## Notes * Queues [per-queue message throughput](https://developers.cloudflare.com/queues/platform/limits/) is currently 5,000 messages per second. If your workload produces more than 5,000 notifications per second, we recommend splitting notification rules across multiple queues. * Rules without prefix/suffix apply to all objects in the bucket. * Overlapping or conflicting rules that could trigger multiple notifications for the same event are not allowed. For example, if you have an `object-create` (or `PutObject` action) rule without a prefix and suffix, then adding another `object-create` (or `PutObject` action) rule with a prefix like `images/` could trigger more than one notification for a single upload, which is invalid. ```json {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/r2/","name":"R2"}},{"@type":"ListItem","position":3,"item":{"@id":"/r2/buckets/","name":"Buckets"}},{"@type":"ListItem","position":4,"item":{"@id":"/r2/buckets/event-notifications/","name":"Event notifications"}}]} ```