Function remote_span_context 

pub fn remote_span_context(
    trace_hex: &str,
    span_hex: &str,
) -> Option<SpanContext>

Available on crate feature otel only.

Build a remote SpanContext from hex-encoded trace + span ids, for re-parenting spans under a span that is no longer live in the current task.

The daemon-hosted worker drives a turn across multiple tasks (execute → suspend at the tool boundary → resume), so its root invoke_agent span cannot stay live for the whole turn. The worker persists the root span’s (trace_id, span_id) and rebuilds a remote parent context from them via this helper so resumed chat calls and child-task execute_tool calls nest under the turn root. Returns None for malformed / zero ids (treated as “no parent”).

Legacy entry point — assumes the remote parent was sampled. It always marks the reconstructed context SAMPLED, which forces a ParentBased sampler to record every re-parented child even when the root span was sampled out. Prefer remote_span_context_with_sampling and pass the root span’s real sampled bit so ratio sampling configured for the root is honoured by its children.