@o11y/local-headless

Node-target local-file collector and static viewer for o11y-client.

Use this when instrumenting a local desktop app (Electron, or any Node-hosted UI) and you want to see telemetry before deciding to upload it to Splunk. This package is never part of the browser bundle, so its viewer adds no bytes to o11y's browser-facing size.

Quick start

import { registerInstrumentedApp } from 'o11y/client';
import { LocalCollector } from '@o11y/local-headless';

const app = registerInstrumentedApp('my-electron-app');
const collector = new LocalCollector({ filePath: './o11y.jsonl' });
app.registerLogCollector(collector);

// On app quit, flush:
// collector.close();

Then open viewer/index.html in a browser and pick your o11y.jsonl to read, group by activity (rootId), and filter by schema.

Where it runs

• Pure-Node app / Electron main process / nodeIntegration renderer — the default FileSink writes the file directly. Works out of the box.

• Context-isolated Electron renderer — the renderer has no fs. Supply a custom Sink whose write(line) forwards over IPC to a main-process handler that owns a FileSink:

  // renderer
  new LocalCollector({ sink: { write: (l) => window.o11yBridge.write(l), close: () => window.o11yBridge.close() } });
  // preload exposes window.o11yBridge; main process owns the FileSink.

Record format

One JSON object per line (v: 1): { v, schemaId, schemaName, ts, rootId, seq, loggerName, data }.

Limitations (v1)

• Logs, activities, and errors only — no metrics.
• No log rotation.
• Static viewer only (no live tail).