---
title: "Announcing Cloudflare K2: serverless event streams"
description: "Cloudflare launched K2, a serverless event streaming service in public beta, to decouple producers and consumers in distributed systems. K2 stores events as an ordered log, allowing independent consumers to read at their own pace without losing data. Under the hood, it builds a partitioned durable log on top of R2 object storage, using atomic operations for ordering. Produce latency at the 99th percentile is about 1 second due to batching writes to R2 segments. K2 is available now for Workers Paid accounts with a 10GB storage limit and 30 MB/s produce per stream, with no billing during beta."
---

# Announcing Cloudflare K2: serverless event streams

[Cloudflare](https://yomu.fyi/company/cloudflare) · Marc Selwan · Oct 1, 2026

**Type:** Announcement

## Summary

Cloudflare launched K2, a serverless event streaming service in public beta, to decouple producers and consumers in distributed systems. K2 stores events as an ordered log, allowing independent consumers to read at their own pace without losing data. Under the hood, it builds a partitioned durable log on top of R2 object storage, using atomic operations for ordering. Produce latency at the 99th percentile is about 1 second due to batching writes to R2 segments. K2 is available now for Workers Paid accounts with a 10GB storage limit and 30 MB/s produce per stream, with no billing during beta.

## Context

Cloudflare built K2 to provide a durable event buffer for its edge infrastructure, where traditional systems like Kafka cannot run due to ephemeral machines and public internet networking.

## Approach / What changed

K2 accumulates writes in memory, then writes them as segment files to R2 object storage. It uses R2’s atomic operations for ordering and strictly incrementing offsets without a separate coordination service.

## Takeaways

- K2 is a fully serverless durable event stream built on R2 object storage, supporting long-term retention and high-scale data movement.
- K2 achieves ordered log semantics by writing batches to R2 segments and using atomic operations to maintain offsets, with a 99th percentile produce latency of about 1 second.
- Unlike Queues, K2 is designed for batch-based consumption and fan-out, trading message-level retries for higher throughput and lower cost per GB.

## FAQ

### How does K2 differ from Cloudflare Queues?

Queues track individual work items with retries and delays, while K2 is built for high-scale data movement and batch consumption. K2 lacks per-message retry logic but offers lower cost and higher throughput for event streaming use cases.

### How is K2 implemented on Cloudflare's edge?

K2 writes events in batches to R2 object storage as segment files, avoiding the need for a coordination service. It uses R2's strongly consistent APIs and atomic operations to achieve ordering and offset tracking.

### What are the current limits of K2 in public beta?

During beta, K2 supports up to 10GB of storage per stream and 30 MB/s produce throughput. Usage is not billed. Higher limits can be requested via the team.

**Tags:** [Cloudflare](https://yomu.fyi/topic/cloudflare), [Event Streaming](https://yomu.fyi/topic/event-streaming), [R2](https://yomu.fyi/topic/r2), [Serverless](https://yomu.fyi/topic/serverless)

- Source: [Cloudflare](https://blog.cloudflare.com/cloudflare-k2-streams)
- Source URL: https://blog.cloudflare.com/cloudflare-k2-streams
- Ingested by Yomu: 2026-10-01T15:00:11.556Z

[Read original post](https://blog.cloudflare.com/cloudflare-k2-streams)