The subscriber's sink endpoint receives HTTP POST requests from the CloudEvents broker. Each request carries one CloudEvent (single delivery mode) or a batch of CloudEvents (batch delivery mode). The subscriber acknowledges receipt with a 2xx HTTP response.
A single CloudEvent delivered in structured content mode where all event data including context attributes is encoded as a JSON object in the HTTP request body.
Content-Type: application/cloudevents+json
BinaryCloudEvent
A single CloudEvent delivered in binary content mode where CloudEvents context attributes are HTTP headers prefixed with 'ce-' and the event data is the raw HTTP body.
Content-Type:
BatchedCloudEvents
A batch of CloudEvents delivered in a single HTTP POST using the application/cloudevents-batch+json media type. Improves throughput by reducing per-event HTTP overhead.
Content-Type: application/cloudevents-batch+json
About AsyncAPI
The AsyncAPI specification describes event-driven APIs the way OpenAPI describes request/response APIs. A channel is the named pipe — a webhook URL, a Kafka topic, a WebSocket route, an MQTT subject — that producers and consumers publish or subscribe to. Each channel carries one or more messages with structured payloads, and an operation declares whether a given party sends or receives on that channel.
Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.
Get an API key
Free tier, no form to fill in. Signing in shares your email address with us — we
store it to create your key and to recognise you if you sign in with another
provider. See our Privacy Policy and
Terms.