[Home](./index.md) > [server](./server.md) > [Telemetry](./server.telemetry.md) > [startSpan](./server.telemetry.startspan.md) ## Telemetry.startSpan() method Executes a callback function within a performance monitoring span. **Signature:** ```typescript static startSpan(options: TelemetrySpanOptions, callback: (span?: Sentry.Span) => T): T; ``` ## Parameters

Parameter	Type	Description
options	[TelemetrySpanOptions](./server.telemetryspanoptions.md)	Configuration for the telemetry span including operation type and attributes.
callback	(span?: Sentry.Span) => T	The function to execute within the performance span.

**Returns:** T The return value of the callback function. ## Remarks This method provides zero-overhead performance monitoring in development environments. In production with Sentry enabled and `SENTRY_ENABLE_TRACING=true`, it creates performance spans for monitoring. The span data is only transmitted to Sentry when performance issues are detected. ## Example ```typescript const result = Telemetry.startSpan({ operation: TelemetrySpanOperation.ENTITIES_TICK, attributes: { entityCount: entities.length, worldId: world.id, }, }, () => { return processEntities(entities); }); ``` \*\*Category:\*\* Telemetry