Struct JsonRpcStreamHandler 

pub struct JsonRpcStreamHandler<W: Write + Send> { /* private fields */ }

Stream handler that emits JSON-RPC events to a writer.

Each StreamHandler callback produces one JSON line using the event types defined in ralph_proto::json_rpc. The handler tracks iteration context and timing to populate event metadata.

Implementations

impl<W: Write + Send> JsonRpcStreamHandler<W>

pub fn new( writer: Arc<Mutex<W>>, iteration: u32, hat: Option<String>, backend: Option<String>, ) -> Self

Creates a new JSON-RPC handler writing to the given writer.

Arguments

• writer - The output sink (wrapped in Arc for thread safety).
• iteration - Current iteration number (1-indexed).
• hat - Current hat ID (e.g., “builder”, “planner”).
• backend - Backend name (e.g., “claude”, “gemini”).

pub fn set_iteration(&mut self, iteration: u32)

Updates the iteration number for subsequent events.

pub fn set_hat(&mut self, hat: Option<String>)

Updates the hat for subsequent events.

pub fn set_backend(&mut self, backend: Option<String>)

Updates the backend for subsequent events.

Trait Implementations

impl<W: Write + Send> StreamHandler for JsonRpcStreamHandler<W>

fn on_text(&mut self, text: &str)

Called when Claude emits text.

fn on_tool_call(&mut self, name: &str, id: &str, input: &Value)

Called when Claude invokes a tool.

fn on_tool_result(&mut self, id: &str, output: &str)

Called when a tool returns results.

fn on_error(&mut self, error: &str)

Called when an error occurs.

fn on_complete(&mut self, result: &SessionResult)

Called when session completes (verbose only).