Logging OpenSearch Serverless API calls using AWS CloudTrail - Amazon OpenSearch Service
OpenSearch Serverless information in CloudTrailOpenSearch Serverless data events in CloudTrailUnderstanding OpenSearch Serverless Data Event entriesUnderstanding OpenSearch Serverless Management Events entries

Logging OpenSearch Serverless API calls using AWS CloudTrail

Amazon OpenSearch Serverless is integrated with AWS CloudTrail, a service that provides a record of actions taken by a user, role, or an AWS service in Serverless.

CloudTrail captures all API calls for OpenSearch Serverless as events. The calls captured include calls from the Serverless section of the OpenSearch Service console and code calls to the OpenSearch Serverless API operations.

If you create a trail, you can enable continuous delivery of CloudTrail events to an Amazon S3 bucket, including events for OpenSearch Serverless. If you don't configure a trail, you can still view the most recent events in the CloudTrail console in Event history.

Using the information collected by CloudTrail, you can determine the request that was made to OpenSearch Serverless, the IP address from which the request was made, who made the request, when it was made, and additional details.

To learn more about CloudTrail, see the AWS CloudTrail User Guide.

OpenSearch Serverless information in CloudTrail

CloudTrail is enabled on your AWS account when you create the account. When activity occurs in OpenSearch Serverless, that activity is recorded in a CloudTrail event along with other AWS service events in Event history. You can view, search, and download recent events in your AWS account. For more information, see Viewing events with CloudTrail Event history.

For an ongoing record of events in your AWS account, including events for OpenSearch Serverless, create a trail. A trail enables CloudTrail to deliver log files to an Amazon S3 bucket. By default, when you create a trail in the console, the trail applies to all AWS Regions.

The trail logs events from all Regions in the AWS partition and delivers the log files to the Amazon S3 bucket that you specify. Additionally, you can configure other AWS services to further analyze and act upon the event data collected in CloudTrail logs. For more information, see the following:

All OpenSearch Serverless actions are logged by CloudTrail and are documented in the OpenSearch Serverless API reference. For example, calls to the CreateCollection, ListCollections, and DeleteCollection actions generate entries in the CloudTrail log files.

Every event or log entry contains information about who generated the request. The identity information helps you determine:

  • Whether the request was made with root or AWS Identity and Access Management (IAM) user credentials.

  • Whether the request was made with temporary security credentials for a role or federated user.

  • Whether the request was made by another AWS service.

For more information, see the CloudTrail userIdentity element.

OpenSearch Serverless data events in CloudTrail

Data events provide information about the resource operations performed on or in a resource (for example, searching or indexing to an OpenSearch Serverless Collection). These are also known as data plane operations. Data events are often high-volume activities. By default, CloudTrail doesn’t log data events. The CloudTrail Event history doesn't record data events.

Additional charges apply for data events. For more information about CloudTrail pricing, see AWS CloudTrail Pricing.

You can log data events for the AWS::AOSS::Collection resource types by using the CloudTrail console, AWS CLI, or CloudTrail API operations. For more information about how to log data events, see Logging data events with the AWS Management Console and Logging data events with the AWS Command Line Interface in the AWS CloudTrail User Guide.

You can configure advanced event selectors to filter on the eventName, readOnly, and resources.ARN fields to log only those events that are important to you. For more information about these fields, see AdvancedFieldSelector in the AWS CloudTrail API Reference.

Understanding OpenSearch Serverless Data Event entries

In the following example:

  • The requestParameters field contains details about the API call made to the collection. It includes the base request path (without query parameters).

  • The responseElements field includes a status code that indicates the outcome of your request when modifying resources. This status code helps you track whether your changes were processed successfully or require attention.

  • OpenSearch Serverless logs CloudTrail data events only for requests that have successfully completed IAM authentication.

 {
      "eventVersion": "1.11",
      "userIdentity": {
        "type": "AssumedRole",
        "principalId": "AROA123456789EXAMPLE",
        "arn": "arn:aws::sts::111122223333:assumed-role/Admin/user-role",
        "accountId": "111122223333",
        "accessKeyId": "access-key",
        "userName": "",
        "sessionContext": {
          "sessionIssuer": {
            "type": "Role",
            "principalId": "AROA123456789EXAMPLE",
            "arn": "arn:aws:iam::111122223333:role/Admin",
            "accountId": "111122223333",
            "userName": "Admin"
          },
          "attributes": {
            "creationDate": "2025-08-15T22:57:38Z",
            "mfaAuthenticated": "false"
          },
          "sourceIdentity": "",
          "ec2RoleDelivery": "",
          "assumedRoot": ""
        },
        "identityProvider": "",
        "credentialId": ""
      },
      "eventTime": "2025-08-15T22:58:00Z",
      "eventSource": "aoss.amazonaws.com",
      "eventName": "Search",
      "awsRegion": "us-east-1",
      "sourceIPAddress": "AWS Internal",
      "userAgent": "python-requests/2.32.3",
      "requestParameters": {
        "pathPrefix": "/_search"
      },
      "responseElements": null,
      "requestID": "2cfee788-EXAM-PLE1-8617-4018cEXAMPLE",
      "eventID": "48d43617-EXAM-PLE1-9d9c-f7EXAMPLE",
      "readOnly": true,
      "resources": [
        {
          "type": "AWS::AOSS::Collection",
          "ARN": "arn:aws:aoss:us-east-1:111122223333:collection/aab9texampletu45xh77"
        }
      ],
      "eventType": "AwsApiCall",
      "managementEvent": false,
      "recipientAccountId": "111122223333",
      "eventCategory": "Data"
    }
  ]
}

Understanding OpenSearch Serverless Management Events entries

A trail is a configuration that enables delivery of events as log files to an Amazon S3 bucket that you specify. CloudTrail log files contain one or more log entries.

An event represents a single request from any source. It includes information about the requested action, the date and time of the action, request parameters, and so on. CloudTrail log files aren't an ordered stack trace of the public API calls, so they don't appear in any specific order.

The following example displays a CloudTrail log entry that demonstrates the CreateCollection action.

{
   "eventVersion":"1.08",
   "userIdentity":{
      "type":"AssumedRole",
      "principalId":"AIDACKCEVSQ6C2EXAMPLE",
      "arn":"arn:aws:iam::123456789012:user/test-user",
      "accountId":"123456789012",
      "accessKeyId":"access-key",
      "sessionContext":{
         "sessionIssuer":{
            "type":"Role",
            "principalId":"AIDACKCEVSQ6C2EXAMPLE",
            "arn":"arn:aws:iam::123456789012:role/Admin",
            "accountId":"123456789012",
            "userName":"Admin"
         },
         "webIdFederationData":{
            
         },
         "attributes":{
            "creationDate":"2022-04-08T14:11:34Z",
            "mfaAuthenticated":"false"
         }
      }
   },
   "eventTime":"2022-04-08T14:11:49Z",
   "eventSource":"aoss.amazonaws.com",
   "eventName":"CreateCollection",
   "awsRegion":"us-east-1",
   "sourceIPAddress":"AWS Internal",
   "userAgent":"aws-cli/2.1.30 Python/3.8.8 Linux/5.4.176-103.347.amzn2int.x86_64 exe/x86_64.amzn.2 prompt/off command/aoss.create-collection",
   "errorCode":"HttpFailureException",
   "errorMessage":"An unknown error occurred",
   "requestParameters":{
      "accountId":"123456789012",
      "name":"test-collection",
      "description":"A sample collection",
      "clientToken":"d3a227d2-a2a7-49a6-8fb2-e5c8303c0718"
   },
   "responseElements": null,
   "requestID":"12345678-1234-1234-1234-987654321098",
   "eventID":"12345678-1234-1234-1234-987654321098",
   "readOnly":false,
   "eventType":"AwsApiCall",
   "managementEvent":true,
   "recipientAccountId":"123456789012",
   "eventCategory":"Management",
   "tlsDetails":{
      "clientProvidedHostHeader":"user.aoss-sample.us-east-1.amazonaws.com"
   }
}