CloudEvents website screenshot

CloudEvents

CloudEvents is a CNCF graduated specification for describing event data in a common way. It provides a consistent format for event metadata across services, platforms, and systems, enabling interoperability between event producers and consumers. The specification includes protocol bindings for HTTP, AMQP, Kafka, MQTT, and NATS, along with SDKs in multiple languages.

CloudEvents publishes 2 APIs on the APIs.io network: Specification and Subscriptions API. Tagged areas include Cloud-Native, Event, Graduated, Interoperability, and Messaging.

The CloudEvents catalog on APIs.io includes 1 event-driven AsyncAPI specification, 1 JSON-LD context, and 3 Spectral governance rulesets.

CloudEvents’ developer surface includes documentation, getting-started guide, engineering blog, changelog, and 13 more developer resources.

🌐 Visit website 📡 Source on GitHub
39.6/100 developing ▬ flat Agent 18/100 agent aware self hosted · Apache-2.0 Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0
AccessFree
1 APIs
Cloud-NativeEventGraduatedInteroperabilityMessagingSpecification

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0
Composite quality — 39.6/100 · developing
Contract Quality 14.0 / 20
Developer Ergonomics 6.1 / 16
Access Clarity 2.1 / 16
Operational Transparency 2.5 / 10
Contract Governance 1.3 / 10
Discoverability 5.3 / 8
Open Source Surface 5.0 / 10
Create-or-Update Ergonomics 0.0 / 10
Agent readiness — 18/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
Documented Reversibility 0 / 6
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 6 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Delegated User Identity 0 / 6
Protected Resource Metadata 0 / 5
Registration Without a Human 0 / 6
Agentic Commerce Well-Known Document 0 / 5
Open Source Surface applies to this provider. This product is open source and we read its repository directly, so Open Source Surface carries 10 points of the composite. It is scored from what the repository actually publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the provider rather than inferred from our own catalog pointers. This facet adds; nothing was taken away to make room for it. An open-source project is not excused from the commercial facets, because exemption would strip it of the points it does earn. If we have the wrong repository, or this product is not open source, say so on your provider repo and we will drop the facet rather than have you publish against it.
Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.
The six quality facets above are damped to 80 points between them, because the conditional facet above carries the other 20. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 80% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/cloudevents: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 12

Individual APIs this provider publishes, each with its own machine-readable definition.

CloudEvents Specification

The CloudEvents specification defines a set of metadata attributes that must be present in every event, including source, type, id, and specversion. It provides a vendor-neutral...

CloudEvents HTTP Protocol Binding

The HTTP protocol binding defines how CloudEvents are transported using HTTP, including structured content mode where the entire event is in the HTTP body, and binary content mo...

CloudEvents Kafka Protocol Binding

The Kafka protocol binding for CloudEvents defines how events are mapped to Apache Kafka messages. It specifies how CloudEvents attributes are encoded as Kafka message headers a...

CloudEvents AMQP Protocol Binding

The AMQP protocol binding for CloudEvents defines how events are mapped to OASIS AMQP 1.0 messages. In structured content mode, event attributes and data are placed in the AMQP ...

CloudEvents MQTT Protocol Binding

The MQTT protocol binding for CloudEvents defines how events are mapped to MQTT 3.1.1 and MQTT 5.0 messages. It supports both structured and binary content modes for IoT and con...

CloudEvents NATS Protocol Binding

The NATS protocol binding for CloudEvents defines how events are mapped to NATS messages. It enables CloudEvents to be produced and consumed over the NATS messaging system, supp...

CloudEvents SQL (CESQL)

CloudEvents SQL (CESQL) is a v1.0 specification that defines a standardized query language for filtering and routing CloudEvents based on their attributes. It provides a SQL-lik...

CloudEvents Go SDK

The official Go SDK for CloudEvents provides libraries for producing and consuming CloudEvents in Go applications. It supports all CloudEvents protocol bindings and content mode...

CloudEvents JavaScript SDK

The official JavaScript SDK for CloudEvents provides libraries for producing and consuming CloudEvents in Node.js and browser environments. It supports structured and binary con...

CloudEvents Java SDK

The official Java SDK for CloudEvents provides libraries for producing and consuming CloudEvents in Java applications. It includes support for HTTP, Kafka, and other transports,...

CloudEvents Python SDK

The official Python SDK for CloudEvents provides libraries for producing and consuming CloudEvents in Python applications. It supports HTTP transport bindings and both structure...

CloudEvents Subscriptions API

Operations for creating and managing event delivery subscriptions. Each subscription specifies a source of events, optional filter criteria, and a sink where matched events are ...

Scroll for all 12

Open Collections 3

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

CloudEvents Subscriptions API

OPEN COLLECTION

CloudEvents Subscriptions API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Cloudevents Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Cloudevents Rate Limits

1 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Cloudevents Finops

FINOPS

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

CloudEvents HTTP Delivery

AsyncAPI definition for CloudEvents delivery over HTTP. This document describes the event-driven interface by which a CloudEvents-compatible broker pushes events to a subscriber...

ASYNCAPI

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Cloudevents Context

4 classes · 27 properties

JSON-LD

Spectral Rules 3

Spectral governance rulesets for linting and validating these APIs.

CloudEvents API Rules

7 rules · 1 errors 6 warnings

SPECTRAL

CloudEvents API Rules

6 rules · 5 warnings 1 info

SPECTRAL

CloudEvents API Rules

9 rules · 3 errors 6 warnings

SPECTRAL

JSON Schema 6

Standalone JSON Schema definitions for this provider's data models.

Error

2 properties

JSON SCHEMA

CloudEvent

10 properties

JSON SCHEMA

Filter

3 properties

JSON SCHEMA

ProtocolSettings

3 properties

JSON SCHEMA

Subscription

8 properties

JSON SCHEMA

SubscriptionRequest

7 properties

JSON SCHEMA

JSON Structure 1

JSON Structure definitions describing this provider's data shapes.

Cloudevents Structure

0 properties

JSON STRUCTURE

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Cloudevents Domain Security

TLSv1.3 · HSTS

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Cloudevents Agentic Access

5 operations · 3 acting

5 operations · 3 acting

AGENTIC

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted
GettingStarted

Documentation 5

Reference material describing how the API behaves

ContributionGuide
ContributionGuide
 Documentation
Documentation
 JSONSchema
JSONSchema
 OpenAPI
OpenAPI
 AsyncAPI
AsyncAPI

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

JSONLD
JSONLD
 Spectral
Spectral

Build 2

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization
 SDKs
SDKs

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity

Operate 2

Status, limits, changes, and where to get help

IssueTracker
IssueTracker
 ChangeLog
ChangeLog

Commercial 1

Pricing, plans, and the legal terms of use

License
License

Company 2

The organization behind the API

Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: cloudevents
name: CloudEvents
description: CloudEvents is a CNCF graduated specification for describing event data in a common way. It provides a consistent
  format for event metadata across services, platforms, and systems, enabling interoperability between event producers and
  consumers. The specification includes protocol bindings for HTTP, AMQP, Kafka, MQTT, and NATS, along with SDKs in multiple
  languages.
url: https://cloudevents.io
deliveryModel:
  model: self-hosted
  license: Apache-2.0
  open_source: true
  commercial: false
  callable_host: false
  label: Self-hosted open source · you run it yourself
  confidence: high
  source:
  - license
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: free
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Free
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/cloudevents.png
tags:
- Cloud-Native
- Event
- Graduated
- Interoperability
- Messaging
- Specification
tags_raw:
- Cloud Native
- Events
- Graduated
- Interoperability
- Messaging
- Specification
created: '2026-03-16'
modified: '2026-05-19'
kind: standard
x-governance: CNCF (Cloud Native Computing Foundation)
x-status: Graduated
x-spec-version: 1.0.2
specificationVersion: '0.23'
type: Index
apis:
- aid: cloudevents:cloudevents-spec
  name: CloudEvents Specification
  description: The CloudEvents specification defines a set of metadata attributes that must be present in every event, including
    source, type, id, and specversion. It provides a vendor-neutral way to describe events that enables consistent routing,
    filtering, and processing across different systems and cloud providers.
  humanURL: https://cloudevents.io/
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/cloudevents/spec/blob/v1.0.2/cloudevents/spec.md
  - type: Reference
    url: https://github.com/cloudevents/spec/blob/main/cloudevents/spec.md
  - type: GitHubRepository
    url: https://github.com/cloudevents/spec
  - type: ChangeLog
    url: https://github.com/cloudevents/spec/releases
  - type: JSONSchema
    url: json-schema/cloudevents-event-schema.json
  - type: AsyncAPI
    url: asyncapi/cloudevents-http-asyncapi.yml
  tags:
  - Event
  - Specification
  - Standards
  tags_raw:
  - Events
  - Specification
  - Standards
- aid: cloudevents:cloudevents-http-binding
  name: CloudEvents HTTP Protocol Binding
  description: The HTTP protocol binding defines how CloudEvents are transported using HTTP, including structured content
    mode where the entire event is in the HTTP body, and binary content mode where event attributes are mapped to HTTP headers.
    This enables REST APIs to produce and consume standardized events.
  humanURL: https://github.com/cloudevents/spec/blob/v1.0.2/cloudevents/bindings/http-protocol-binding.md
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/cloudevents/spec/blob/v1.0.2/cloudevents/bindings/http-protocol-binding.md
  - type: Reference
    url: https://github.com/cloudevents/spec/blob/main/cloudevents/bindings/http-protocol-binding.md
  tags:
  - HTTP
  - Protocol Binding
  - REST
- aid: cloudevents:cloudevents-kafka-binding
  name: CloudEvents Kafka Protocol Binding
  description: The Kafka protocol binding for CloudEvents defines how events are mapped to Apache Kafka messages. It specifies
    how CloudEvents attributes are encoded as Kafka message headers and how the event payload is placed in the Kafka message
    value, enabling standardized event interchange over Kafka topics.
  humanURL: https://github.com/cloudevents/spec/blob/v1.0.2/cloudevents/bindings/kafka-protocol-binding.md
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/cloudevents/spec/blob/v1.0.2/cloudevents/bindings/kafka-protocol-binding.md
  - type: Reference
    url: https://github.com/cloudevents/spec/blob/main/cloudevents/bindings/kafka-protocol-binding.md
  tags:
  - Kafka
  - Messaging
  - Protocol Binding
- aid: cloudevents:cloudevents-amqp-binding
  name: CloudEvents AMQP Protocol Binding
  description: The AMQP protocol binding for CloudEvents defines how events are mapped to OASIS AMQP 1.0 messages. In structured
    content mode, event attributes and data are placed in the AMQP message application data section; in binary content mode,
    event data is placed as-is with attributes mapped to AMQP message properties.
  humanURL: https://github.com/cloudevents/spec/blob/v1.0.2/cloudevents/bindings/amqp-protocol-binding.md
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/cloudevents/spec/blob/v1.0.2/cloudevents/bindings/amqp-protocol-binding.md
  - type: Reference
    url: https://github.com/cloudevents/spec/blob/main/cloudevents/bindings/amqp-protocol-binding.md
  tags:
  - AMQP
  - Messaging
  - Protocol Binding
- aid: cloudevents:cloudevents-mqtt-binding
  name: CloudEvents MQTT Protocol Binding
  description: The MQTT protocol binding for CloudEvents defines how events are mapped to MQTT 3.1.1 and MQTT 5.0 messages.
    It supports both structured and binary content modes for IoT and constrained device environments that use MQTT as their
    messaging protocol.
  humanURL: https://github.com/cloudevents/spec/blob/main/cloudevents/bindings/mqtt-protocol-binding.md
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/cloudevents/spec/blob/main/cloudevents/bindings/mqtt-protocol-binding.md
  tags:
  - IoT
  - MQTT
  - Protocol Binding
- aid: cloudevents:cloudevents-nats-binding
  name: CloudEvents NATS Protocol Binding
  description: The NATS protocol binding for CloudEvents defines how events are mapped to NATS messages. It enables CloudEvents
    to be produced and consumed over the NATS messaging system, supporting both publish/subscribe and request/reply patterns.
  humanURL: https://github.com/cloudevents/spec/blob/main/cloudevents/bindings/nats-protocol-binding.md
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/cloudevents/spec/blob/main/cloudevents/bindings/nats-protocol-binding.md
  tags:
  - Messaging
  - NATS
  - Protocol Binding
- aid: cloudevents:cloudevents-cesql
  name: CloudEvents SQL (CESQL)
  description: CloudEvents SQL (CESQL) is a v1.0 specification that defines a standardized query language for filtering and
    routing CloudEvents based on their attributes. It provides a SQL-like syntax for writing event filter expressions that
    can be used across different event processing platforms and systems.
  humanURL: https://github.com/cloudevents/spec/blob/main/cesql/spec.md
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/cloudevents/spec/blob/main/cesql/spec.md
  tags:
  - Filtering
  - Specification
  - SQL
- aid: cloudevents:cloudevents-sdk-go
  name: CloudEvents Go SDK
  description: The official Go SDK for CloudEvents provides libraries for producing and consuming CloudEvents in Go applications.
    It supports all CloudEvents protocol bindings and content modes, and includes client implementations for HTTP, Kafka,
    and other transports.
  humanURL: https://github.com/cloudevents/sdk-go
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://cloudevents.github.io/sdk-go/
  - type: GitHubRepository
    url: https://github.com/cloudevents/sdk-go
  tags:
  - Client Library
  - Go
  - SDK
- aid: cloudevents:cloudevents-sdk-javascript
  name: CloudEvents JavaScript SDK
  description: The official JavaScript SDK for CloudEvents provides libraries for producing and consuming CloudEvents in Node.js
    and browser environments. It supports structured and binary content modes over HTTP and other transports.
  humanURL: https://github.com/cloudevents/sdk-javascript
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/cloudevents/sdk-javascript/blob/main/README.md
  - type: GitHubRepository
    url: https://github.com/cloudevents/sdk-javascript
  tags:
  - Client Library
  - JavaScript
  - SDK
- aid: cloudevents:cloudevents-sdk-java
  name: CloudEvents Java SDK
  description: The official Java SDK for CloudEvents provides libraries for producing and consuming CloudEvents in Java applications.
    It includes support for HTTP, Kafka, and other transports, and integrates with popular Java frameworks.
  humanURL: https://github.com/cloudevents/sdk-java
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/cloudevents/sdk-java/blob/main/README.md
  - type: GitHubRepository
    url: https://github.com/cloudevents/sdk-java
  tags:
  - Client Library
  - Java
  - SDK
- aid: cloudevents:cloudevents-sdk-python
  name: CloudEvents Python SDK
  description: The official Python SDK for CloudEvents provides libraries for producing and consuming CloudEvents in Python
    applications. It supports HTTP transport bindings and both structured and binary content modes.
  humanURL: https://github.com/cloudevents/sdk-python
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/cloudevents/sdk-python/blob/main/README.md
  - type: GitHubRepository
    url: https://github.com/cloudevents/sdk-python
  tags:
  - Client Library
  - Python
  - SDK
- aid: cloudevents:cloudevents-subscriptions-api
  name: CloudEvents Subscriptions API
  description: Operations for creating and managing event delivery subscriptions. Each subscription specifies a source of
    events, optional filter criteria, and a sink where matched events are delivered.
  humanURL: https://cloudevents.io/
  tags:
  - Subscription
  tags_raw:
  - Subscriptions
  properties:
  - type: OpenAPI
    url: openapi/cloudevents-subscriptions-api-openapi.yml
  - type: Documentation
    url: https://github.com/cloudevents/spec/blob/main/subscriptions/spec.md
common:
- type: IssueTracker
  url: https://github.com/cloudevents/spec/issues
- type: ContributionGuide
  url: https://github.com/cloudevents/spec/blob/main/docs/CONTRIBUTING.md
- type: License
  name: Apache-2.0
  url: https://github.com/cloudevents/spec/blob/main/LICENSE
- type: AgenticAccess
  url: agentic-access/cloudevents-agentic-access.yml
- type: DomainSecurity
  url: security/cloudevents-domain-security.yml
- type: Website
  url: https://cloudevents.io
- type: Documentation
  url: https://github.com/cloudevents/spec
- type: GettingStarted
  url: https://github.com/cloudevents/spec/blob/main/cloudevents/primer.md
- type: Blog
  url: https://cloudevents.io/blog/
- type: GitHubOrganization
  url: https://github.com/cloudevents
- type: SDKs
  url: https://github.com/cloudevents/spec/blob/main/cloudevents/SDK.md
- type: ChangeLog
  url: https://github.com/cloudevents/spec/releases
- type: JSONSchema
  url: json-schema/cloudevents-event-schema.json
- type: OpenAPI
  url: openapi/_original/cloudevents-subscriptions-openapi.yml
- type: AsyncAPI
  url: asyncapi/cloudevents-http-asyncapi.yml
- type: JSONLD
  url: json-ld/cloudevents-context.jsonld
- type: Spectral
  url: rules/cloudevents-rules.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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