# GetUserId
Retrieves the `UserId` in an identity store.
**Note**
If you have access to a member account, you can use this API operation from the member account. For more information, see [Limiting access to the identity store from member accounts](https://docs.aws.amazon.com/singlesignon/latest/userguide/manage-your-accounts.html#limiting-access-from-member-accounts) in the * AWS IAM Identity Center User Guide*.
## Request Syntax
```
{
"AlternateIdentifier": { ... },
"IdentityStoreId": "string"
}
```
## Request Parameters
For information about the parameters that are common to all actions, see [Common Parameters](CommonParameters.md).
The request accepts the following data in JSON format.
** [AlternateIdentifier](#API_GetUserId_RequestSyntax) **
A unique identifier for a user or group that is not the primary identifier. This value can be an identifier from an external identity provider (IdP) that is associated with the user, the group, or a unique attribute. For the unique attribute, the only valid paths are ` userName` and `emails.value`.
Type: [AlternateIdentifier](API_AlternateIdentifier.md) object
**Note: **This object is a Union. Only one member of this object can be specified or returned.
Required: Yes
** [IdentityStoreId](#API_GetUserId_RequestSyntax) **
The globally unique identifier for the identity store.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 36.
Pattern: `d-[0-9a-f]{10}$|^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}`
Required: Yes
## Response Syntax
```
{
"IdentityStoreId": "string",
"UserId": "string"
}
```
## Response Elements
If the action is successful, the service sends back an HTTP 200 response.
The following data is returned in JSON format by the service.
** [IdentityStoreId](#API_GetUserId_ResponseSyntax) **
The globally unique identifier for the identity store.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 36.
Pattern: `d-[0-9a-f]{10}$|^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}`
** [UserId](#API_GetUserId_ResponseSyntax) **
The identifier for a user in the identity store.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 47.
Pattern: `([0-9a-f]{10}-|)[A-Fa-f0-9]{8}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{12}`
## Errors
For information about the errors that are common to all actions, see [Common Error Types](CommonErrors.md).
** AccessDeniedException **
You do not have sufficient access to perform this action.
** Reason **
Indicates the reason for an access denial when returned by KMS while accessing a Customer Managed KMS key. For non-KMS access-denied errors, this field is not included.
** RequestId **
The identifier for each request. This value is a globally unique ID that is generated by the identity store service for each sent request, and is then returned inside the exception if the request fails.
HTTP Status Code: 400
** InternalServerException **
The request processing has failed because of an unknown error, exception or failure with an internal server.
** RequestId **
The identifier for each request. This value is a globally unique ID that is generated by the identity store service for each sent request, and is then returned inside the exception if the request fails.
** RetryAfterSeconds **
The number of seconds to wait before retrying the next request.
HTTP Status Code: 500
** ResourceNotFoundException **
Indicates that a requested resource is not found.
** Reason **
Indicates the reason for a resource not found error when the service is unable to access a Customer Managed KMS key. For non-KMS permission errors, this field is not included.
** RequestId **
The identifier for each request. This value is a globally unique ID that is generated by the identity store service for each sent request, and is then returned inside the exception if the request fails.
** ResourceId **
The identifier for a resource in the identity store that can be used as `UserId` or `GroupId`. The format for `ResourceId` is either `UUID` or `1234567890-UUID`, where `UUID` is a randomly generated value for each resource when it is created and `1234567890` represents the ` IdentityStoreId` string value. In the case that the identity store is migrated from a legacy SSO identity store, the `ResourceId` for that identity store will be in the format of `UUID`. Otherwise, it will be in the `1234567890-UUID` format.
** ResourceType **
An enum object indicating the type of resource in the identity store service. Valid values include USER, GROUP, and IDENTITY\$1STORE.
HTTP Status Code: 400
** ThrottlingException **
Indicates that the principal has crossed the throttling limits of the API operations.
** Reason **
Indicates the reason for the throttling error when the service is unable to access a Customer Managed KMS key. For non-KMS permission errors, this field is not included.
** RequestId **
The identifier for each request. This value is a globally unique ID that is generated by the identity store service for each sent request, and is then returned inside the exception if the request fails.
** RetryAfterSeconds **
The number of seconds to wait before retrying the next request.
HTTP Status Code: 400
** ValidationException **
The request failed because it contains a syntax error.
** Reason **
Indicates the reason for the validation error when the service is unable to access a Customer Managed KMS key. For non-KMS permission errors, this field is not included.
** RequestId **
The identifier for each request. This value is a globally unique ID that is generated by the identity store service for each sent request, and is then returned inside the exception if the request fails.
HTTP Status Code: 400
## Examples
### Example
This example retrieves the user ID based on the user name.
#### Sample Request
```
{
"IdentityStoreId": "d-1234567890",
"AlternateIdentifier": {
"UniqueAttribute": {
"AttributePath": "userName",
"AttributeValue": "johndoe"
}
}
}
```
#### Sample Response
```
{
"UserId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"IdentityStoreId": "d-1234567890"
}
```
## 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/identitystore-2020-06-15/GetUserId)
+ [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/identitystore-2020-06-15/GetUserId)
+ [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/identitystore-2020-06-15/GetUserId)
+ [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/identitystore-2020-06-15/GetUserId)
+ [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/identitystore-2020-06-15/GetUserId)
+ [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/identitystore-2020-06-15/GetUserId)
+ [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/identitystore-2020-06-15/GetUserId)
+ [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/identitystore-2020-06-15/GetUserId)
+ [AWS SDK for Python](https://docs.aws.amazon.com/goto/boto3/identitystore-2020-06-15/GetUserId)
+ [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/identitystore-2020-06-15/GetUserId)