Span Events to Logs Migration

Use this skill to migrate instrumentation from the Span Event API (AddEvent, RecordException, and language equivalents) to the Logs API, following the accepted OTEP 4430 deprecation plan.

Background

The OpenTelemetry project accepted a plan to deprecate Span.AddEvent and Span.RecordException in favor of emitting events and exceptions through the Logs API. Span Events as a concept remain valid -- they can be emitted via logs that correlate to the active span, and optionally bridged back into the span proto.

Status as of 2026-09-09: OTEP 4430 is accepted, log-based event/exception emission is specified in the Logs API, and the SDK "event to span event bridge" is specified with Development status. The trace API methods AddEvent/RecordException are not yet formally marked Deprecated in the specification -- that step is still pending. Treat existing span-event calls as migration candidates, not automatically invalid code; some SDK-specific equivalents have already changed status (for example OpenTelemetry .NET's Activity.RecordException extension is [Obsolete] in favor of Activity.AddException, which is still a span-event API).

See references/deprecation-plan.md for the full context.

Workflow

0. Prepare before migrating.

• check the project's OpenTelemetry SDK version supports log-based events (check the otel-sdk-versions skill's version index if available)
• identify whether the project has a LoggerProvider configured; if not, one must be set up
• determine if downstream consumers (backends, dashboards, alerts) depend on span events appearing in the span proto envelope