Struct TeeEmitter 

pub struct TeeEmitter { /* private fields */ }

An AgentEmitter that forwards every event to each of its children, in registration order. The host builds one around [BroadcastEmitter (→ TUI), ExtensionEmitter (→ plugin handlers)] so a single AgentHarnessOptions .agent_emitter slot feeds both consumers: the TUI keeps rendering from its broadcast receiver, and plugin on() handlers receive translated StablePluginEvents.

emit awaits each child in turn (the loop awaits emit, so order matches registration); try_emit calls each child’s try_emit (the tool on_update path — non-blocking). A child that panics is isolated by the child’s own catch_unwind where applicable (the ExtensionEmitter does); the BroadcastEmitter cannot panic (it’s a tx.send). We do NOT wrap the fan-out itself in catch_unwind — each child is responsible for its own soundness, and a generic wrapper would mask a child’s contract violation.

Implementations

impl TeeEmitter

pub fn new(emitters: Vec<Arc<dyn AgentEmitter>>) -> Self

Build a tee over the given emitters. Order is preserved: emit/try_emit visit them front-to-back. A single-child tee is a trivial passthrough (the host uses that when no extensions loaded, so the code path is uniform).

Trait Implementations

impl AgentEmitter for TeeEmitter

fn emit(&self, event: AgentEvent) -> BoxFuture<'static, ()>

Async emit — awaited by the loop so event order matches emit call order.

fn try_emit(&self, event: AgentEvent)

Sync non-blocking emit for the tool on_update path. Must never panic and must never block (it’s called from a &dyn Fn closure inside execute). Default impl is a no-op so custom emitters opt in.