TRACING-W3C-CONTEXT

HTTP tracing context propagation standard.

Definition

traceparent format: version(2)-trace_id(32 hex)-parent_id(16 hex)-trace_flags(2 hex). tracestate vendor-specific extensions key=value. Replaces the older b3, b3-multi (Zipkin), X-Datadog-Trace-Id (Datadog). Auto-injection by OpenTelemetry SDK in outgoing HTTP requests.

Origin

W3C Distributed Tracing WG active since 2018 ; Level 1 Recommendation February 2020 ; Level 2 December 2024.

Example in context

A frontend → backend HTTP call carries the header traceparent: 00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01.

Related terms

• OTel Traces — consumer.