The Event Viewer shows you what the LaunchDarkly JavaScript SDK is doing under the hood — flag evaluations, context payloads, tracking events, and streaming connections. This page simulates that traffic so you can try the viewer without a real LD environment.
Drag the button above to your bookmarks bar, then click it on any page with the LD SDK.
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Send simulated SDK traffic to the viewer.
Send All fires every operation below in sequence: flag evaluation, identify, feature & summary events, custom tracking, goals, and streaming.
Flag evaluations happen when the SDK initializes. It sends the current context to LaunchDarkly and gets back every feature flag value — booleans, strings, numbers, JSON objects — with variation and reason info.
Identify tells the SDK who the current user is. Edit the context and click Send.
Custom events are tracking calls via track('event-key', data, metricValue). Edit the event data and click Send.
key is the event name, metricValue is the numeric metric, data is the JSON payload.
Conversion goals tell the SDK what user actions to watch for — pageview (URL match) or click (CSS selector match). The viewer validates each goal against the current page.
Streaming is how the SDK receives flag updates in real time via Server-Sent Events (SSE). The viewer shows when the connection opens, messages received, and errors.
Evaluate sends a single flag with a specific value to the viewer, evaluated against a context you define. Results are additive — each click adds to the viewer panel.