Struct MessageStream 

pub struct MessageStream<'a, P: EventProducer<StateT>, StateT: AgentState = JsonValue> { /* private fields */ }

Helper for streaming a text message piece by piece.

This struct manages the lifecycle of a streaming text message, automatically generating message IDs and emitting the appropriate events.

Example

let msg = MessageStream::start(&producer).await?;
msg.content("Hello, ").await?;
msg.content("world!").await?;
let message_id = msg.end().await?;

Implementations

impl<'a, P: EventProducer<StateT>, StateT: AgentState> MessageStream<'a, P, StateT>

pub async fn start(producer: &'a P) -> Result<Self, ServerError>

Start a new message stream.

Emits a TextMessageStart event with a randomly generated message ID.

pub async fn start_with_id( producer: &'a P, message_id: MessageId, ) -> Result<Self, ServerError>

Start a new message stream with a specific message ID.

pub async fn content(&self, delta: impl Into<String>) -> Result<(), ServerError>

Append content to the message.

Emits a TextMessageContent event with the given delta. Empty deltas are silently ignored.

pub async fn end(self) -> Result<MessageId, ServerError>

End the message stream.

Emits a TextMessageEnd event and returns the message ID. Consumes the stream to prevent further content being added.

pub fn message_id(&self) -> &MessageId

Get the message ID for this stream.