axum-impl-sse

What problem does it solve?

Axum SSE handlers often fail to compile or misbehave in production because the stream item types, keep-alive behavior, and Event builder rules are easy to get subtly wrong.

Core Features & Use Cases

• Correct SSE handler types: Ensures you return Sse with a stream that yields Result<Event, E> (including the required .map(Ok) for infallible streams).
• Production-stable long-lived streaming: Prevents dropped connections and “quiet stream goes dead” issues by applying KeepAlive.
• Safe, panic-free Event construction: Avoids runtime panics caused by calling single-use Event builder methods more than once, or placing newlines/CR/LF where they are forbidden.
• SSE vs WebSockets decisioning: Guides you to choose SSE for receive-only browser clients using EventSource.

Quick Start

Implement an Axum route that returns Sse<impl Stream<Item = Result<Event, Infallible>>>, builds each message with Event::default().data(...), lifts the stream with .map(Ok), and attaches .keep_alive(KeepAlive::default()) for long-lived updates.