Struct RpcStreamingContext 

pub struct RpcStreamingContext {
    pub caller_origin: u64,
    pub call_id: u64,
    pub deadline_ns: u64,
    pub headers: Vec<RpcHeader>,
    pub cancellation: RpcCancellationToken,
    pub trace_context: Option<TraceContext>,
}

Context handed to an RpcClientStreamingHandler::call. Same shape as RpcContext minus the eager payload (the request stream delivers chunk bodies on the fly) and plus the per-call deadline_ns (which would otherwise have ridden on the eager payload).

Bidi streaming plan (Phase B).

Fields

caller_origin: u64

AEAD-verified caller origin_hash. Same source as RpcContext::caller_origin.

call_id: u64

Caller-generated correlation id. Matches the initial REQUEST’s call_id and every subsequent REQUEST_CHUNK / CANCEL / REQUEST_GRANT for this call.

deadline_ns: u64

Absolute deadline (unix nanos) from the initial REQUEST. 0 means no deadline; the fold does NOT auto-cancel on deadline (handlers self-supervise via tokio timers, same contract as the unary fold).

headers: Vec<RpcHeader>

Per-chunk metadata headers from the initial REQUEST. Per-REQUEST_CHUNK headers are NOT surfaced at the substrate layer — the typed SDK veneer (Phase E) is where header inspection across chunks lives (if it lands at all; the plan defers per-chunk-headers as opt-in raw-path access).

cancellation: RpcCancellationToken

Cancellation signal. Flipped by the fold when a DISPATCH_RPC_CANCEL arrives for this call’s call_id. Long-running handlers should select! on cancellation.cancelled(); the request stream also terminates on cancellation, but the token is the authoritative signal (the stream’s terminator is shared with REQUEST_END).

trace_context: Option<TraceContext>

W3C Trace Context propagated from the caller’s initial REQUEST. Same semantics as RpcContext::trace_context.