Struct PromptStream 

pub struct PromptStream { /* private fields */ }

Non-Clone observation of one accepted prompt’s transient output.

Dropping this value releases observation only. An implementation’s accepted prompt remains owned by its conversation and is cancelled through ConversationBackend::abort. Completion or error fuses the stream; premature EOF becomes one protocol error. A caller source owns bounded production and accepted-work cleanup.

use agents_kit::prompt::{PromptEvent, PromptResponse, PromptStream};
let runtime = tokio::runtime::Builder::new_current_thread().build()?;
runtime.block_on(async {
    let mut output = PromptStream::from_stream(futures_util::stream::iter([
        Ok(PromptEvent::OutputDelta { text: "ready".into() }),
        Ok(PromptEvent::Completed(PromptResponse::new("done".into(), None))),
    ]));
    assert!(matches!(output.recv().await.transpose()?, Some(PromptEvent::OutputDelta { .. })));
    let Some(PromptEvent::Completed(response)) = output.recv().await.transpose()? else { panic!("terminal response"); };
    assert_eq!(response.output(), "done");
    assert!(output.recv().await.is_none());
    Ok::<(), agents_kit::KitError>(())
})?;

Implementations

impl PromptStream

pub fn from_stream<S>(stream: S) -> Self

where S: Stream<Item = Result<PromptEvent, KitError>> + Send + 'static,

Adapts a caller’s concrete value stream without normalizing a backend.

The source may be non-Unpin. It must produce ordered real text and one authoritative completed response or error, retain accepted work after observer drop, and keep pending output bounded.

See PromptStream for a complete caller-stream example.

pub async fn recv(&mut self) -> Option<Result<PromptEvent, KitError>>

Receives the next observation, or None after its single terminal item.

Cancelling this read does not abort the accepted prompt. A premature source EOF returns Protocol once rather than claiming successful output.

Errors

A source failure is yielded once with prompt/publication context. EOF before completion yields Protocol with IncompleteStream; terminal results fuse subsequent reads to None.

use agents_kit::{error::ErrorKind, prompt::PromptStream};
let mut output = PromptStream::from_stream(futures_util::stream::empty());
let error = output.recv().await.expect("one terminal error").unwrap_err();
assert_eq!(error.kind(), ErrorKind::Protocol);
assert!(output.recv().await.is_none());