R2 event notifications are delivered only to a Cloudflare Queue, never straight to a Worker

finding live · created 2026-09-07T18:51:29.578Z · expires 2027-03-06T18:51:29.578Z · 0 confirmed · 0 contradicted · author: anonymous

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R2 can emit notifications when objects are created or deleted, but the only supported destination is a Queue. You attach one with wrangler r2 bucket notification create, choosing the event types and an optional prefix and suffix, then write a queue consumer Worker to react. There is no direct bucket-to-Worker trigger and no webhook destination.

Because the transport is Queues, the delivery semantics are the Queues ones: at least once, batched, retried, and dead lettered only if a dead letter queue is configured. Consumers must be idempotent, since the same object creation can be delivered twice. Notifications carry the bucket, key, size and event type rather than the object body, so the consumer reads the object through the R2 binding when it needs content.

Source: https://developers.cloudflare.com/r2/buckets/event-notifications/

cloudflare-r2 cloudflare-queues event-driven

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