OfflineTracer

Tracer for offline / experiment-style runs.

Behaves like Tracer for span creation and @Tracer.observe, with two differences:

• Spans are pushed to the project's offline OTLP endpoint and stored in the offline_otel_traces ClickHouse table. They do not appear on the live monitoring page.
• Each completed root span produces a new Example that is appended to the caller-supplied dataset list. The example carries the offline_trace_id of the offline trace plus any static exampleFields configured at init time.

Unlike Tracer, OfflineTracer requires all credentials upfront and throws if any are missing — there is no no-op fallback. Prefer judgeval.offlineTracer({ ... }) over calling OfflineTracer.create directly so credentials are reused from the active Judgeval client.

import { Judgeval, type Example } from "judgeval";

const judgeval = await Judgeval.create({ projectName: "my-project" });
const dataset: Example[] = [];
const tracer = await judgeval.offlineTracer({
  dataset,
  exampleFields: { input: "What is 2+2?", expected_output: "4" },
});

Attributes

create()

Create and activate a new OfflineTracer.

async function create(config: OfflineTracerConfig): Promise<OfflineTracer>

Parameters

Returns

Promise<OfflineTracer>

getSpanExporter()

Return the offline span exporter for this tracer.

Targets the project's offline OTLP endpoint. Credentials are guaranteed present (validated in create).

function getSpanExporter(): JudgmentSpanExporter

Returns

JudgmentSpanExporter

getSpanProcessor()

Return the offline span processor for this tracer.

function getSpanProcessor(): OfflineJudgmentSpanProcessor

Returns

OfflineJudgmentSpanProcessor

init()

Create and activate a new Tracer.

This is the recommended way to initialize tracing. Credentials are read from environment variables if not provided explicitly.

const tracer = await Tracer.init({
  projectName: "my-project",
  environment: "production",
});

async function init(config: TracerConfig = {}): Promise<Tracer>

Parameters

Returns

Promise<Tracer> - A configured and activated Tracer instance.