# Pub/Sub API Features

Learn about some of the features of Pub/Sub API.

| Feature                   | Pub/Sub API                                                                                                      |
| ------------------------- | ---------------------------------------------------------------------------------------------------------------- |
| Event Encoding            | Binary ([Apache Avro](https://avro.apache.org/))                                                                 |
| Protocol                  | [gRPC](https://grpc.io/docs/what-is-grpc/) and protocol buffers                                                  |
| Subscription model        | Pull-based—the client requests the number of events to receive as they become available in the event bus.        |
| Subscription flow control | Client specifies how many events to receive for a Subscribe call based on event processing speed in the client.  |
| Publish status            | Final publishing result returned indicates that the event was successfully published or that the publish failed. |

**See Also**

- [Pull Subscription and Flow Control](/docs/platform/pub-sub-api/guide/flow-control.md)