Real time push messaging
Push messaging allows events that occur on servers to be pushed to end users without the user having to refresh or request an update. There are several types of push messaging, suitable for different use cases. Using Fastly for real time messaging reduces load on your origin servers, allows messages to be routed efficiently to large numbers of clients, and offers extremely low latency.
| WebSockets passthrough | Streaming miss | Fanout | Pub/Sub App | |
|---|---|---|---|---|
 |  |  |  | |
| Delivery model | One-to-one | One-to-many | Brokered | Brokered |
| Origin-client relationship | Each client has a pipe directly to origin. Fastly disregards the content. | Fastly's cache allows multiple clients to get the same streamed response from origin | Events you publish to Fastly are routed to clients based on channel subscriptions | Events you publish to Fastly are routed to clients based on channel subscriptions |
| Platforms | VCL and Compute | VCL and Compute | Compute only | Compute only |
| Server to client | Yes | Yes | Yes | Yes |
| Client to server | Yes | No | Yes | Yes |
| DDoS protection | Yes | Yes | Yes | Yes |
| Supported transports | WebSockets | Server-sent-events | WebSockets Server-sent-events Long poll | WebSockets Server-sent-events MQTT |
| Learn more > | Learn more > | Learn more > | Learn more > |
HINT: Push messaging is a major part of many real time communications use cases. Explore our RTC topic page for ideas and inspiration for what to do with Fastly's push messaging features.
