Struct MessageStream 

pub struct MessageStream { /* private fields */ }

A Stream of StreamEvents decoded from a streaming POST /v1/messages response, which simultaneously accumulates a final Message.

Drive it with your async runtime via futures_util::StreamExt. Each item is a Result<StreamEvent>: a decode failure or an in-stream error event yields Err and ends the stream. After the stream is exhausted (or at any point), final_message returns the message assembled so far; collect_final drains the stream and returns the complete Message.

Examples

use crimson_crab::api::MessagesRequest;
use crimson_crab::types::MessageParam;

let request = MessagesRequest::builder()
    .model("claude-opus-4-8")
    .max_tokens(1024)
    .messages(vec![MessageParam::user("Hi")])
    .build()?;
let message = client.messages().stream(&request).await?.collect_final().await?;
println!("{}", message.text());

Implementations

impl MessageStream

pub fn final_message(&self) -> Option<&Message>

Returns the message accumulated so far, or None before the message_start event has been seen.

Examples

use bytes::Bytes;
use crimson_crab::streaming::MessageStream;
use futures_util::stream;

let stream =
    MessageStream::from_byte_stream(stream::iter(Vec::<crimson_crab::Result<Bytes>>::new()));
assert!(stream.final_message().is_none());

pub async fn collect_final(self) -> Result<Message>

Drains the stream to completion and returns the accumulated Message.

Returns the first error encountered (a decode failure, an in-stream error event, or a transport error). Returns Error::Stream if the stream ended without a message_start event.

Examples

use crimson_crab::api::MessagesRequest;
use crimson_crab::types::MessageParam;

let request = MessagesRequest::builder()
    .model("claude-opus-4-8")
    .max_tokens(1024)
    .messages(vec![MessageParam::user("Hi")])
    .build()?;
let message = client.messages().stream(&request).await?.collect_final().await?;
let _ = message.stop_reason;

Trait Implementations

impl Stream for MessageStream

type Item = Result<StreamEvent, Error>

Values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.