LaunchDarkly Developer Documentation

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The debugger

The debugger gives you real-time insight into the events your application is sending to LaunchDarkly, so you can ensure that you've set LaunchDarkly up correctly.

The debugger must be the active tab in its browser window in order to receive events. You can have a second window open with your application, if you need to click around in your app in order to generate events. When first opened, the debugger needs to connect to the event stream, and may take up to 30 seconds to start receiving events.

Please note that in high-volume environments, the events sent to the debugger may be sampled. When this happens, the debugger will only receive a subset of events instead of every event.

Flag events

The debugger displays evaluation counts and variation breakdowns for each flag evaluated since the debugger was opened. Click on a flag or select it from the dropdown to access individual event information.

Flag evaluation events are summarized by default, to minimize the transfer of unnecessary data. To get detailed evaluation event information for a flag, select it and click "Debug". This will temporarily enable detailed events for that flag, which will be displayed as they are received. Additional information, including the user attributes used for evaluation, can be viewed by clicking on an individual event.

Older SDK versions that do not summarize evaluations will send detailed events for every evaluation. In this case, the debug option is not available and individual events can be seen by selecting the desired flag.

The minimum required version for each platform SDK to use summary events is shown below:

.NET: 5.0.0
Go: 4.0.0
Java: 4.0.0
Node: 5.0.0
Python: 6.0.0
Ruby: 4.0.0
JavaScript: 2.0.0
Android: 2.4.0
iOS: 2.13.0

PHP: The PHP SDK does not itself support summary events. However, when PHP is used with LD Relay, the LD Relay event-forwarding mode has the ability to turn the events received from the PHP SDK into summary events. This requires that you are using PHP SDK version 3.1.0 or higher.

LD Relay: If you are using LD Relay with PHP you will need to upgrade LD Relay to version 4.0.0 or higher. Other SDKs do not require an LD Relay update to use summary events.

User events

There are two types of user events: identify events are explicitly triggered by your application code, and index events are automatically triggered by the LaunchDarkly SDK based on flag evaluations. Click on a user to see individual event information.

Goal events

Goal events will only be shown for customers who have A/B testing enabled. There are three types of goal events: click, page view, and custom, corresponding to the kind of goal that triggered the event. Event summaries for each goal are displayed by default; individual events can be viewed by clicking on the desired goal.

The debugger

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