Cloudflare K2 Enters Public Beta: Serverless Event Streams Built on R2

Cloudflare has launched K2 in public beta, a durable event streaming service for its Developer Platform. The company announced the product on October 1, 2026, describing it as a serverless primitive that stores events as an ordered log and lets consumers read them at their own pace.

The pitch is aimed at a familiar problem: in traditional RPC architectures, producers and consumers have to match each other in both scale and time. If producers send more data than consumers can handle, or a downstream service goes down, events get dropped. That gets harder when several consumers need to process the same data independently — for example, an ecommerce backend emitting transaction events that both an analytics system and a fraud detection service need to read.

K2 sits in the middle as a buffer. You send events to a stream, and consumers can read them in different ways, including splitting reads across a set of consumers or delivering every message to every consumer. According to Cloudflare, it scales to large volumes of data and supports long-term retention, so extended consumer downtime does not mean lost data.

Built on R2 instead of Kafka

Under the hood, K2 implements a partitioned, durable log on top of R2 object storage. Cloudflare says that offloading replication and consensus to the storage layer makes the application layer simpler, cheaper and faster, and separates compute from storage so each can scale independently.

The company built K2 first for its own needs, as a durable buffer on the edge and initially as the ingestion layer for Basin Pipelines. Cloudflare notes that most companies would reach for Apache Kafka here, but its edge spans a huge number of servers across more than 335 cities, with small machine slices, ephemeral machines and networking often over the public internet — conditions that make traditional distributed systems software hard to run.

Object storage brings its own constraint: R2, like other object stores, does not support appends, the standard operation on a log. Cloudflare’s answer is to accumulate writes in memory on an edge service and then write complete segments large enough to justify the cost of each read and write.

How to try it

K2 is available now in public beta. Cloudflare says you can create your first stream in seconds by following the guide in its announcement post. The company has not published pricing details in the material available.

Related reading

Sources

• Announcing Cloudflare K2: serverless event streams — Cloudflare Blog