# DescribeEventSource
Returns the full configuration and lifecycle state of an EventSource.
## Request Parameters
** EventSourceArn **
EventSource ARN: event-sourcev2///. The type segment is set by the service (aws.service for AWS service events, aws.partner for partner events) and is not part of the resource's name. The id segment is a 25-character identifier generated by the service.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 1011.
Pattern: `arn:aws(-[a-z0-9]+)*:events:[a-z][a-z0-9]*(-[a-z0-9]+)*:([0-9]{12}):event-sourcev2\/(aws\.service|aws\.partner)\/[A-Za-z0-9][\.\-_A-Za-z0-9]{0,255}\/[a-z0-9]{25}`
Required: Yes
## Response Elements
The following elements are returned by the service.
** Configuration **
Discriminated EventSource configuration. Exactly one variant must be set.
Type: [EventSourceConfiguration](API_EventSourceConfiguration.md) object
**Note: **This object is a Union. Only one member of this object can be specified or returned.
** CreationTime **
The time the EventSource was created.
Type: Timestamp
** Description **
Free-text description. Used by every resource type that has one: event buses, subscribers, and event sources.
Type: String
Length Constraints: Minimum length of 0. Maximum length of 512.
Pattern: `[^\u0000-\u001F\u007F-\u009F\u2028\u2029]*(?![\s\S]).*`
** EventBusArn **
The Amazon Resource Name (ARN) that uniquely identifies an event bus.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 1011.
Pattern: `arn:aws(-[a-z0-9]+)*:events:[a-z][a-z0-9]*(-[a-z0-9]+)*:([0-9]{12}):event-busv2\/[A-Za-z0-9][\.\-_A-Za-z0-9]{0,255}\/[a-z0-9]{25}`
** EventSourceArn **
EventSource ARN: event-sourcev2///. The type segment is set by the service (aws.service for AWS service events, aws.partner for partner events) and is not part of the resource's name. The id segment is a 25-character identifier generated by the service.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 1011.
Pattern: `arn:aws(-[a-z0-9]+)*:events:[a-z][a-z0-9]*(-[a-z0-9]+)*:([0-9]{12}):event-sourcev2\/(aws\.service|aws\.partner)\/[A-Za-z0-9][\.\-_A-Za-z0-9]{0,255}\/[a-z0-9]{25}`
** LastModifiedTime **
The time the EventSource was last modified.
Type: Timestamp
** Name **
EventSource name. First character alphanumeric; the rest may add '.', '-', '\_'. Names may not begin with the reserved "aws." prefix. The grammar matches the ARN local-name segment in EventSourceArn (event-sourcev2///), mirroring EventBusName, so a name the ARN cannot represent cannot be created.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 256.
Pattern: `(?!aws\.)[A-Za-z0-9][\.\-_A-Za-z0-9]*`
** Revoked **
True when the bus owner has withdrawn this EventSource. Present only when true, so an absent member means the EventSource is not revoked. Revocation is terminal: it never returns to false. Mutating operations on a revoked EventSource fail with InvalidStateException, except DeleteEventSource, which stays available so a revoked EventSource can still be cleaned up.
Type: Boolean
** State **
Lifecycle state of an EventSource. Revocation is reported by the Revoked flag.
Type: String
Valid Values: `CREATING | ACTIVE | UPDATING | CREATE_FAILED | UPDATE_FAILED | DELETING | DELETE_FAILED`
## Errors
For information about the errors that are common to all actions, see [Common Error Types](CommonErrors.md).
** AccessDeniedException **
The caller does not have the permissions required to perform the operation. This error is also returned when the operation cannot use the AWS KMS key for the event bus.
HTTP Status Code: 403
** InternalException **
The request failed because of an internal service error. Retry the request.
HTTP Status Code: 500
** InvalidInputException **
A request parameter is missing or not valid.
HTTP Status Code: 400
** ResourceNotFoundException **
The resource does not exist.
HTTP Status Code: 404
** ThrottlingException **
The request was throttled because it exceeds a request rate limit. Retry the request with backoff.
HTTP Status Code: 429
## See Also
For more information about using this API in one of the language-specific AWS SDKs, see the following:
+ [AWS Command Line Interface V2](https://docs.aws.amazon.com/goto/cli2/eventbridgev2-2025-05-15/DescribeEventSource)
+ [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/eventbridgev2-2025-05-15/DescribeEventSource)
+ [AWS SDK for C\+\+](https://docs.aws.amazon.com/goto/SdkForCpp/eventbridgev2-2025-05-15/DescribeEventSource)
+ [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/eventbridgev2-2025-05-15/DescribeEventSource)
+ [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/eventbridgev2-2025-05-15/DescribeEventSource)
+ [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/eventbridgev2-2025-05-15/DescribeEventSource)
+ [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/eventbridgev2-2025-05-15/DescribeEventSource)
+ [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/eventbridgev2-2025-05-15/DescribeEventSource)
+ [AWS SDK for Python (Boto3)](https://docs.aws.amazon.com/goto/boto3/eventbridgev2-2025-05-15/DescribeEventSource)
+ [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/eventbridgev2-2025-05-15/DescribeEventSource)