Event Subscribers

autotel-subscribers sends events to multiple product analytics platforms simultaneously.

Track once, send everywhere:

• Primary metrics → OpenTelemetry
• Product events → PostHog / Mixpanel / Amplitude
• Customer data → Segment
• Custom integrations → Webhooks

Installation

npm install autotel autotel-subscribers
npm install posthog-node    # For PostHog
npm install mixpanel        # For Mixpanel

Quick Start

import { init, track } from 'autotel';
import { PostHogSubscriber } from 'autotel-subscribers/posthog';

init({
  service: 'my-app',
  events: {
    subscribers: [new PostHogSubscriber({ apiKey: process.env.POSTHOG_KEY! })],
  },
});

track('user.signup', { userId: '123', plan: 'pro' });

Built-in Subscribers

| Subscriber | Import | | ----------------------- | -------------------------------------------- | | PostHog | autotel-subscribers/posthog | | Mixpanel | autotel-subscribers/mixpanel | | Segment | autotel-subscribers/segment | | Amplitude | autotel-subscribers/amplitude | | Webhook | autotel-subscribers/webhook | | Slack | autotel-subscribers/slack | | ArchitectureSnapshot | autotel-subscribers/architecture-snapshot |

ArchitectureSnapshotSubscriber

Records every event your code emits — names, field paths, runtime types, sample values, producer/consumer edges — into a single snapshot. The output feeds autotel-eventcatalog to diff what production does against what your EventCatalog says it does.

import { init } from 'autotel';
import { ArchitectureSnapshotSubscriber } from 'autotel-subscribers/architecture-snapshot';

const snapshot = new ArchitectureSnapshotSubscriber({ service: 'my-app' });

init({ service: 'my-app', subscribers: [snapshot] });

// ...run integration tests, then persist the snapshot...
await writeFile('snapshot.json', JSON.stringify(snapshot.toSnapshot(), null, 2));

For each tracked event the snapshot includes fieldStats — observed runtime types and sampled primitive values per dotted field path — which powers type-drift and value-drift detection downstream.

Custom Subscriber

import { EventSubscriber, EventPayload } from 'autotel-subscribers';

class MySubscriber extends EventSubscriber {
  readonly name = 'MySubscriber';

  protected async sendToDestination(payload: EventPayload): Promise<void> {
    await fetch('https://api.example.com/events', {
      method: 'POST',
      body: JSON.stringify(payload),
    });
  }
}

Middleware

import {
  applyMiddleware,
  retryMiddleware,
  samplingMiddleware,
  enrichmentMiddleware,
} from 'autotel-subscribers/middleware';

const subscriber = applyMiddleware(
  new MySubscriber(),
  retryMiddleware({ maxRetries: 3 }),
  samplingMiddleware({ rate: 0.5 }),
  enrichmentMiddleware({ region: 'us-east-1' }),
);

Examples

• example-subscribers — PostHog, Slack, and webhook subscribers with event filtering and funnel tracking.

Entry Points

• autotel-subscribers — Base class + re-exports
• autotel-subscribers/posthog — PostHog
• autotel-subscribers/mixpanel — Mixpanel
• autotel-subscribers/segment — Segment
• autotel-subscribers/amplitude — Amplitude
• autotel-subscribers/webhook — Webhook
• autotel-subscribers/slack — Slack
• autotel-subscribers/architecture-snapshot — Architecture snapshot for drift detection
• autotel-subscribers/middleware — Middleware composition
• autotel-subscribers/testing — Test harnesses