Class: Tracer

Prefactor TypeScript SDK

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Prefactor TypeScript SDK / @prefactor/core / Tracer

Class: Tracer

Defined in: packages/core/src/tracing/tracer.ts:66

Tracer manages the lifecycle of spans.

The tracer is responsible for:

• Creating spans with unique IDs
• Managing span lifecycle (start/end)
• Delegating to the transport layer for span emission
• Handling agent instance lifecycle

Example

const tracer = new Tracer(transport);

const span = tracer.startSpan({
  name: 'llm-call',
  spanType: SpanType.LLM,
  inputs: { prompt: 'Hello' }
});

try {
  // ... do work ...
  tracer.endSpan(span, { outputs: { response: 'Hi!' } });
} catch (error) {
  tracer.endSpan(span, { error });
}

Constructors

Constructor

new Tracer(transport, partition?): Tracer

Defined in: packages/core/src/tracing/tracer.ts:75

Initialize the tracer.

Parameters

transport

Transport

The transport to use for emitting spans

partition?

number

The partition for ID generation. If not provided, a random partition will be generated.

Returns

Tracer

Methods

startSpan()

startSpan(options): Span

Defined in: packages/core/src/tracing/tracer.ts:88

Start a new span

Parameters

options

StartSpanOptions

Span configuration options

Returns

Span

The created span

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endSpan()

endSpan(span, options?): void

Defined in: packages/core/src/tracing/tracer.ts:128

End a span and emit it to the transport

Parameters

span

Span

The span to end

options?

EndSpanOptions

End span options (outputs, error, token usage)

Returns

void

---

close()

close(): Promise<void>

Defined in: packages/core/src/tracing/tracer.ts:168

Close the tracer and flush any pending spans

Returns

Promise<void>

Promise that resolves when the tracer is closed

---

startAgentInstance()

startAgentInstance(): void

Defined in: packages/core/src/tracing/tracer.ts:172

Returns

void

---

finishAgentInstance()

finishAgentInstance(): void

Defined in: packages/core/src/tracing/tracer.ts:180

Returns

void