The protocol is used to report events to the backend. The [doc](../concepts-and-designs/event.md) introduces the definition of an event, and [the protocol repository](https://github.com/apache/skywalking-data-collect-protocol/blob/master/event) defines gRPC services and message formats of events.
Report `JSON` format events via HTTP API, the endpoint is `http://<oap-address>:12800/v3/events`.
JSON event record example:
```json
[
{
"uuid":"f498b3c0-8bca-438d-a5b0-3701826ae21c",
"source":{
"service":"SERVICE-A",
"instance":"INSTANCE-1"
},
"name":"Reboot",
"type":"Normal",
"message":"App reboot.",
"parameters":{},
"startTime":1628044330000,
"endTime":1628044331000
}
]
```
### 3rd-party instrument protocol
3rd-party instrument protocols are not defined by SkyWalking. They are just protocols/formats with which SkyWalking is compatible, and SkyWalking could receive them from their existing libraries. SkyWalking starts with supporting Zipkin v1, v2 data formats.