Browser API

Install @leracherry/tracelens-browser and call init() once in a browser entry point.

init(options)

Starts observers, browser instrumentation, correlation, batching, and the configured transport. It returns the same async shutdown function exported as shutdown().

const stop = init({
  app: 'dashboard',
  release: '1.0.0',
  endpoint: '/__tracelens',
});

await stop();

Calling init() twice without a successful shutdown throws. Invalid sampling, batching, or flush values throw before browser APIs are patched.

trace(name, fn)

Records named synchronous or asynchronous application work and preserves the original return value or error.

const report = await trace('generate-report', () => generateReport());

The returned value is always a promise because TraceLens records both synchronous and asynchronous functions through one API.

mark(name)

Creates performance.mark('tracelens:' + name) and emits a TraceLens mark when the runtime is active.

mark('hydration-complete');

shutdown()

Disconnects observers, restores patched fetch and XHR methods, stops the timer, and drains queued telemetry. Delivery failures reject without discarding the batch so shutdown can be retried.

await shutdown();

MemoryTransport

Stores sanitized events in memory. It is useful for tests and adapters.

const transport = new MemoryTransport();
init({ app: 'test', transport });

Transport

interface Transport {
  send(events: readonly AnyTraceLensEvent[]): Promise<void>;
}

A rejected send() call is treated as retryable. Implementations should reject only when sending the same batch again is safe.

Diagnostic helpers

• describeElement(element, privacy) returns the privacy-filtered descriptor used for interaction names.
• getActiveInteractionId(at?) returns the current correlation candidate.
• recordReactRender(sample) is the bridge used by @leracherry/tracelens-react.
• sanitizeTelemetryUrl(value, privacy) applies the public URL privacy policy.

See configuration for every option and browser instrumentation for behavior and browser support.