Janus Client SDK

A lightweight JavaScript library for tracking events from web applications. Automatically handles batching, retries, rate limiting, and persistence.

Lightweight (~3KB)Auto RetryBatchingPersistence

Automatic Page Tracking

Default Behavior#

By default, Janus automatically tracks page views when the SDK initializes. No manual Janus.page() calls are needed for basic page view tracking.

javascript

// This automatically tracks a page view
Janus.init('jns_your_api_key_here');

// The above is equivalent to:
// Janus.init('jns_your_api_key_here');
// Janus.page();

SPA Navigation Support#

For Single Page Applications (React, Vue, etc.), Janus monitors the History API to automatically track route changes. This includes pushState, replaceState, and browser back/forward navigation.

javascript

// SPA navigation is tracked automatically
// When your router calls history.pushState(), a page view is recorded

// React Router, Vue Router, and similar libraries
// all trigger page views automatically

Disabling Auto-Tracking#

If you need full control over page view tracking, you can disable automatic tracking:

javascript

// Disable all automatic page view tracking
Janus.init('jns_your_api_key_here', {
    trackPageViews: false,      // No page view on init
    trackSPANavigation: false   // No SPA route change tracking
});

// Now track pages manually where needed
Janus.page('Dashboard');

Partial Auto-Tracking#

You can mix automatic and manual tracking. For example, disable only the initial page view but keep SPA tracking:

javascript

// Disable initial page view, but keep SPA tracking
Janus.init('jns_your_api_key_here', {
    trackPageViews: false,       // Skip initial page view
    trackSPANavigation: true     // Still track SPA navigation (default)
});

// Manually track after some setup is complete
if (userIsReady) {
    Janus.page('Home');
}

HTTP API Automatic Context

Need Help?

If you have questions or run into issues, check out our troubleshooting guide or reach out to our support team.

Troubleshooting Guide