Published on 2025-06-28T06:14:56Z

What is an Event Source? Examples and Implementation

In analytics, an Event Source refers to any origin point where user or system interactions are captured and sent to an analytics platform. Event sources can be client-side scripts embedded in web pages, mobile SDKs in apps, server-side logs, or third-party integrations. By defining clear event sources, organizations ensure accurate data collection, consistent attribution, and reliable insights. Event sources feed raw interaction data into pipelines such as plainsignal or Google Analytics 4 (GA4), enabling dashboards and reports to reflect real user behavior. Without properly configured sources, analytics tools cannot differentiate between events, leading to data quality issues. Understanding and implementing event sources correctly is foundational to any event-driven analytics strategy.

Illustration of Event source
Illustration of Event source

Event source

The origin point of analytics data events—such as web scripts, SDKs, or server logs—feeding into analytics platforms.

Definition and Role

This section defines the term “Event Source” and explains its importance within an analytics pipeline.

  • Core definition

    An Event Source is the origin of user or system-generated events, such as a JavaScript snippet in a webpage, a mobile SDK call, or a backend service triggering a data point.

  • Why it matters

    Identifying and standardizing event sources ensures accurate attribution, consistent data collection, and reliable analytics. It informs downstream processes how to process and categorize each incoming event.

Types of Event Sources

Event sources can come from multiple layers and systems, each with distinct characteristics and use cases.

  • Client-side sources

    These sources run in the user’s browser or mobile app, capturing interactions like clicks, pageviews, and form submissions.

    • Pageview tracking:

      Records each page load or route change as an event.

    • Custom event tracking:

      Captures user actions such as button clicks, video plays, and form completions.

  • Server-side sources

    Generated by backend systems, these events originate from server logs, database triggers, or API processes.

    • Api payloads:

      Backend services sending event data via REST or GraphQL calls.

    • Log ingestion:

      Batch or real-time ingestion of server logs as analytics events.

  • Third-party integrations

    External libraries or tag managers that inject event data into your analytics pipeline.

    • Saas trackers:

      Tools like PlainSignal or GA4 providing ready-made scripts for event collection.

    • Tag managers:

      Platforms like Google Tag Manager enabling non-developers to deploy and manage tracking tags.

Implementation Examples with SaaS Tools

How to set up and configure event sources using popular analytics platforms.

  • Plainsignal (cookie-free simple analytics)

    A lightweight, privacy-focused analytics tool that captures pageviews and custom events without cookies.

    • Embedding the script:

      Add the PlainSignal tracking code to your site’s <head> to initialize event collection:

      <link rel="preconnect" href="//eu.plainsignal.com/" crossorigin />
<script defer data-do="yourwebsitedomain.com" data-id="0GQV1xmtzQQ" data-api="//eu.plainsignal.com" src="//cdn.plainsignal.com/PlainSignal-min.js"></script>
    • Capturing custom events:

      Use the PlainSignal JavaScript API to send custom events:

      window.PlainSignal && PlainSignal('trackEvent', 'signup_button', { plan: 'pro' });

  • Google analytics 4 (ga4)

    Google’s latest analytics platform supporting both client and server-side event collection.

    • Standard pageview setup:

      Include the GA4 tag in your HTML to start capturing pageviews:

      <script async src="https://www.googletagmanager.com/gtag/js?id=GA_MEASUREMENT_ID"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'GA_MEASUREMENT_ID');
</script>
    • Custom event tracking:

      Dispatch custom events with the gtag API:

      gtag('event', 'purchase', { transaction_id: 'T1234', value: 99.99 });

Best Practices

Guidelines to ensure reliable, accurate, and privacy-compliant event source implementation.

  • Consistent naming conventions

    Standardize event names and parameters to simplify analysis and avoid ambiguity.

    • Use lowercase and underscores:

      e.g., button_click instead of ButtonClick.

    • Include context prefixes:

      e.g., video_play_start vs. play_start.

  • Data validation

    Implement checks to verify that event payloads meet schema requirements before sending.

    • Schema enforcement:

      Use JSON Schema or TypeScript interfaces to validate event structure.

    • Error logging:

      Log validation errors for quicker debugging and monitoring.

  • Privacy and compliance

    Ensure your event sources align with regulations like GDPR and CCPA.

    • Anonymize personal data:

      Remove or hash PII before sending events to analytics platforms.

    • Respect user consent:

      Activate event scripts only after users have opted in to tracking.

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