Function stream_query 

pub async fn stream_query<F>(
    claude: &Claude,
    cmd: &QueryCommand,
    handler: F,
) -> Result<CommandOutput>
where
    F: FnMut(StreamEvent),

Execute a command with streaming output, calling a handler for each NDJSON line.

This spawns the claude process and reads stdout line-by-line, parsing each as a JSON event and passing it to the handler. Useful for progress tracking and real-time output processing.

Dropping the returned future mid-flight kills the spawned claude process and, on Unix, its whole process group (SIGKILL): an abandoned run does not keep executing in the background, and the subprocesses it spawned for tool use die with it. Events already dispatched to the handler are not rolled back.

Example

use claude_wrapper::{Claude, QueryCommand, OutputFormat};
use claude_wrapper::streaming::{StreamEvent, stream_query};

let claude = Claude::builder().build()?;

let cmd = QueryCommand::new("explain quicksort")
    .output_format(OutputFormat::StreamJson);

let output = stream_query(&claude, &cmd, |event: StreamEvent| {
    if let Some(t) = event.event_type() {
        println!("[{t}] {:?}", event.data);
    }
}).await?;