> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chronosphere.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Enable change events on traces

When troubleshooting issues, on-call engineers want as much information as possible
to quickly identify the root cause. To expedite problem resolution, you can overlay
[change events](/overview/types/change-events) on tracing data to help determine whether
a code deploy, alerting monitor, feature flag, or other change in your environment
might have caused, or correlates to, the issue you're trying to solve.

Overlaying change events on tracing data adds vertical lines to the tracing timeline
graph, which responds to criteria you add in the **Query builder**. You can pin
individual or groups of change events to the graph, and then explore the details of
what changed, where the change occurred, and when the change happened.

To overlay change events on tracing data:

1. In the navigation menu select
   **<Icon icon="compass" /> Explorers <span aria-label="and then">></span> Trace Explorer**.

2. Choose the time period to display results for, which defaults to the last 15
   minutes.

3. Use the **Query builder** to
   [define a search](/investigate/querying/traces#define-a-search), and then
   click **Run**.

4. Click **Events** to open the **Events** panel.

5. Select the [event categories](/observe/enable-events/use-events#categorize-change-events-intentionally)
   you want to display, and then click **Save**.

   The selected change event categories display on the timeline graph.

6. In the timeline graph, click a change event or group of change events to pin them
   to the graph.

7. In the pinned pane on the graph, click **View details** to display the **Change
   event** or **Change event group** panel. Use this panel to view details about the
   selected events, such as the source app that generated the event, when the event
   happened, and any links or labels associated with the event.

To view more details about the selected events, click **Open in Changes Explorer** to
open Changes Explorer scoped to that query. In Changes Explorer, you can
[modify the filter](/investigate/querying/filter-events) to specify a different
time period, and change the criteria included in the query.