<p>Returns a list of the fields that are included in log events in the specified log group. Includes the percentage of log events that contain each field. The search is limited to a time period that you specify.</p> <p>You can specify the log group to search by using either <code>logGroupIdentifier</code> or <code>logGroupName</code>. You must specify one of these parameters, but you can't specify both. </p> <p>In the results, fields that start with <code>@</code> are fields generated by CloudWatch Logs. For example, <code>@timestamp</code> is the timestamp of each log event. For more information about the fields that are generated by CloudWatch logs, see <a href="https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/CWL_AnalyzeLogData-discoverable-fields.html">Supported Logs and Discovered Fields</a>.</p> <p>The response results are sorted by the frequency percentage, starting with the highest percentage.</p> <p>If you are using CloudWatch cross-account observability, you can use this operation in a monitoring account and view data from the linked source accounts. For more information, see <a href="https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-Unified-Cross-Account.html">CloudWatch cross-account observability</a>.</p>

{
  "success": true,
  "data": {
    "id": "abc123",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters"
  }
}