Summary
Cloudflare added new Workers runtime tracing APIs, startActiveSpan() and span.end(), that let developers create custom spans beyond a single callback to instrument long-running operations such as stream pipelines.
What changed
Cloudflare Workers gained tracing.startActiveSpan() and span.end() runtime APIs, enabling custom, explicitly-ended spans beyond single-callback tracing for finer-grained instrumentation of long-running work like stream pipelines.
Why it matters
As more agent and inference logic runs inside Workers, first-class span control makes it easier to profile and debug long-running requests in production, narrowing the observability gap between edge runtimes and traditional application servers.
Evidence excerpt
New tracing.startActiveSpan() and span.end() runtime APIs enable custom spans beyond single callbacks. Useful for instrumenting long-running operations like stream pipelines.