CloudEvents

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Events are everywhere. However, event producers tend to describe events differently.

The lack of a common way of describing events means developers must constantly re-learn how to consume events. This also limits the potential for libraries, tooling and infrastructure to aide the delivery of event data across environments, like SDKs, event routers or tracing systems. The portability and productivity we can achieve from event data is hindered overall.

CloudEvents is a specification for describing event data in common formats to provide interoperability across services, platforms and systems.

CloudEvents has received a large amount of industry interest, ranging from major cloud providers to popular SaaS companies. CloudEvents is hosted by the Cloud Native Computing Foundation (CNCF) and was approved as a Cloud Native sandbox level project on May 15, 2018, an incubator project on Oct 24, 2019 and a graduated project on Jan 25, 2024 (announcement).

CloudEvents Documents

| | Latest Release | Working Draft | | :---------------------------- | :-----------------------------------------------------------------------------: | :--------------------------------------------------------------------------------------: | | Core Specification: | | CloudEvents | v1.0.2 | WIP | | | | Optional Specifications: | | AMQP Protocol Binding | v1.0.2 | WIP | | AVRO Event Format | v1.0.2 | WIP | | AVRO Compact Event Format | | WIP | | HTTP Protocol Binding | v1.0.2 | WIP | | JSON Event Format | v1.0.2 | WIP | | Kafka Protocol Binding | v1.0.2 | WIP | | MQTT Protocol Binding | v1.0.2 | WIP | | NATS Protocol Binding | v1.0.2 | WIP | | WebSockets Protocol Binding | - | WIP | | Protobuf Event Format | v1.0.2 | WIP | | XML Event Format | - | WIP | | Web hook | v1.0.2 | WIP | | | | Additional Documentation: | | CloudEvents Primer | v1.0.2 | WIP | | CloudEvents Adapters | - | Not versioned | | CloudEvents SDK Requirements | - | Not versioned | | Documented Extensions | - | Not versioned | | Proprietary Specifications | - | Not versioned |

The most recent release of the CloudEvents specifications can be found via the ce@stable tag.

Other Specifications

| | Latest Release | Working Draft | | :-------------- | :-------------------------------------------------------------: | :---------------------------: | | CE SQL | v1.0.0 | WIP | | Subscriptions | - | WIP |

The most recent release of the CESQL specification can be found via the cesql@stable tag.

The Registry and Pagination specifications can now be found in the xRegistry/spec repo.

Additional release related information: Historical releases and changelogs

If you are new to CloudEvents, it is recommended that you start by reading the Primer for an overview of the specification's goals and design decisions, and then move on to the core specification.

Since not all event producers generate CloudEvents by default, there is documentation describing the recommended process for adapting some popular events into CloudEvents, see CloudEvents Adapters.

SDKs

In addition to the documentation mentioned above, there are also a set of language specific SDKs being developed:

• C#/.NET
• Go
• Java
• Javascript
• PHP
• PowerShell
• Python
• Ruby
• Rust

The SDK requirements document provides information on how the SDKs are managed and what is expected of each one. The SDK feature support table is a good resource to see which features, event formats and bindings are supported by each SDK.

For more information about how the SDKs operate, please see the following documents:

• SDK Governance
• SDK Maintainer Guidlines
• SDK PR Guidlines

Community and Docs

Learn more about the people and organizations who are creating a dynamic cloud native ecosystem by making our systems interoperable with CloudEvents.

• Our Governance documentation.
• Contributing guidance.
• Roadmap
• Adopters - See "Integrations".
• Contributors: people and organizations who helped us get started or are actively working on the CloudEvents specification.
• Presentations, notes and other misc shared docs
• Demos & open source -- if you have something to share about your use of CloudEvents, please submit a PR!
• Potential CloudEvents v2 work items
• Code of Conduct

Security Concerns

If there is a security concern with one of the CloudEvents specifications, or with one of the project's SDKs, please send an email to cncf-cloudevents-security@lists.cncf.io.

A security assessment was performed by Trail of Bits in October 2022. The report can be found here or on the Trail of Bits [website](https://github.com/trailofbits/publications/blob/master/r