v1.2.0

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

Best Practices

Initialize Early#

Initialize the SDK in your <head> to capture events as early as possible:
html
<head>
    <script src="https://addjanus.ca/janus.js"></script>
    <script>
        Janus.init('jns_your_api_key_here');
    </script>
</head>

Track Meaningful Events#

Focus on specific, actionable events:
javascript
// Good: Specific, actionable events
Janus.track('checkout_started', { cartValue: 150 });
Janus.track('feature_used', { feature: 'export_pdf' });


// Avoid: Too generic or too frequent
Janus.track('click');  // Too vague
Janus.track('mousemove');  // Too noisy

Identify Users After Login#

javascript
async function onLoginSuccess(user) {
    Janus.identify(user.id, {
        email: user.email,
        plan: user.subscription
    });
    Janus.track('login_success');
}

Reset on Logout#

javascript
function onLogout() {
    Janus.track('logout');
    Janus.reset();  // Generate new anonymous ID
}

Use Debug Mode During Development#

javascript
Janus.init('jns_your_api_key_here', {
    debug: true  // See all SDK activity in console
});
Setting Up API KeysTroubleshooting

Need Help?

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

Troubleshooting Guide