Backend-neutral SSE client APIs with two explicit public modes:

• [oneshot::EventSource] consumes a single accepted body stream
• [replayable::EventSource] reconnects through a backend-neutral connector

The default reqwest feature provides extension trait impls for reqwest::Response and reqwest::RequestBuilder, including validation of HTTP status and content-type.

One-Shot Usage

Inside an async context:

# async fn demo() -> Result<(), Box<dyn std::error::Error>> {
use futures_util::StreamExt;
let response = reqwest::Client::new()
    .get("https://example.com/v1/stream")
    .send()
    .await?;

use eventsrc_client::oneshot::EventSourceExt as _;

let mut stream = response.event_source()?;

while let Some(event) = stream.next().await {
    let event = event?;
    println!("{}", event.data());
}
# Ok(())
# }

Replayable Usage

Inside an async context:

# async fn demo() -> Result<(), Box<dyn std::error::Error>> {
use eventsrc_client::replayable::EventSourceExt as _;
use futures_util::StreamExt;

let mut stream = reqwest::Client::new()
    .get("https://example.com/events")
    .event_source()?;

while let Some(event) = stream.next().await {
    let event = event?;
    println!("{}", event.data());
}
# Ok(())
# }

Retry Policies

Replayable mode separates retry classification from retry timing:

• [replayable::EventSource] decides which transitions are retryable
• [replayable::RetryPolicy] decides how long to wait before retrying

Built-in policies:

• [replayable::ConstantBackoff] for a fixed delay
• [replayable::ExponentialBackoff] for failure-sensitive backoff
• [replayable::NeverRetry] to stop reconnecting after the first disconnect or failure