# CreateStackInstances
<a name="API_CreateStackInstances"></a>

Creates stack instances for the specified accounts, within the specified Amazon Web Services Regions. A stack instance refers to a stack in a specific account and Region. You must specify at least one value for either `Accounts` or `DeploymentTargets`, and you must specify at least one value for `Regions`.

**Note**  
The maximum number of organizational unit (OUs) supported by a `CreateStackInstances` operation is 50.  
If you need more than 50, consider the following options:  
 *Batch processing:* If you don't want to expose your OU hierarchy, split up the operations into multiple calls with less than 50 OUs each.
 *Parent OU strategy:* If you don't mind exposing the OU hierarchy, target a parent OU that contains all desired child OUs.

## Request Parameters
<a name="API_CreateStackInstances_RequestParameters"></a>

 For information about the parameters that are common to all actions, see [Common Parameters](CommonParameters.md).

 **Accounts.member.N**   
[Self-managed permissions] The account IDs of one or more Amazon Web Services accounts that you want to create stack instances in the specified Region(s) for.  
You can specify `Accounts` or `DeploymentTargets`, but not both.  
Type: Array of strings  
Pattern: `^[0-9]{12}$`   
Required: No

 ** CallAs **   
[Service-managed permissions] Specifies whether you are acting as an account administrator in the organization's management account or as a delegated administrator in a member account.  
By default, `SELF` is specified. Use `SELF` for StackSets with self-managed permissions.  
+ If you are signed in to the management account, specify `SELF`.
+ If you are signed in to a delegated administrator account, specify `DELEGATED_ADMIN`.

  Your Amazon Web Services account must be registered as a delegated administrator in the management account. For more information, see [Register a delegated administrator](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/stacksets-orgs-delegated-admin.html) in the * Amazon CloudFormation User Guide*.
Type: String  
Valid Values: `SELF | DELEGATED_ADMIN`   
Required: No

 ** DeploymentTargets **   
[Service-managed permissions] The Amazon Organizations accounts in which to create stack instances in the specified Amazon Web Services Regions.  
You can specify `Accounts` or `DeploymentTargets`, but not both.  
Type: [DeploymentTargets](API_DeploymentTargets.md) object  
Required: No

 ** OperationId **   
The unique identifier for this StackSet operation.  
The operation ID also functions as an idempotency token, to ensure that CloudFormation performs the StackSet operation only once, even if you retry the request multiple times. You might retry StackSet operation requests to ensure that CloudFormation successfully received them.  
Repeating this StackSet operation with a new operation ID retries all stack instances whose status is `OUTDATED`.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 128.  
Pattern: `[a-zA-Z0-9][-a-zA-Z0-9]*`   
Required: No

 ** OperationPreferences **   
Preferences for how CloudFormation performs this StackSet operation.  
Type: [StackSetOperationPreferences](API_StackSetOperationPreferences.md) object  
Required: No

 **ParameterOverrides.member.N**   
A list of StackSet parameters whose values you want to override in the selected stack instances.  
Any overridden parameter values will be applied to all stack instances in the specified accounts and Amazon Web Services Regions. When specifying parameters and their values, be aware of how CloudFormation sets parameter values during stack instance operations:  
+ To override the current value for a parameter, include the parameter and specify its value.
+ To leave an overridden parameter set to its present value, include the parameter and specify `UsePreviousValue` as `true`. (You can't specify both a value and set `UsePreviousValue` to `true`.)
+ To set an overridden parameter back to the value specified in the StackSet, specify a parameter list but don't include the parameter in the list.
+ To leave all parameters set to their present values, don't specify this property at all.
During StackSet updates, any parameter values overridden for a stack instance aren't updated, but retain their overridden value.  
You can only override the parameter *values* that are specified in the StackSet; to add or delete a parameter itself, use [UpdateStackSet](https://docs.amazonaws.cn/AWSCloudFormation/latest/APIReference/API_UpdateStackSet.html) to update the StackSet template.  
Type: Array of [Parameter](API_Parameter.md) objects  
Required: No

 **Regions.member.N**   
The names of one or more Amazon Web Services Regions where you want to create stack instances using the specified Amazon Web Services accounts.  
Type: Array of strings  
Pattern: `^[a-zA-Z0-9-]{1,128}$`   
Required: Yes

 ** StackSetName **   
The name or unique ID of the StackSet that you want to create stack instances from.  
Type: String  
Required: Yes

## Response Elements
<a name="API_CreateStackInstances_ResponseElements"></a>

The following element is returned by the service.

 ** OperationId **   
The unique identifier for this StackSet operation.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 128.  
Pattern: `[a-zA-Z0-9][-a-zA-Z0-9]*` 

## Errors
<a name="API_CreateStackInstances_Errors"></a>

For information about the errors that are common to all actions, see [Common Error Types](CommonErrors.md).

 ** InvalidOperation **   
The specified operation isn't valid.  
HTTP Status Code: 400

 ** LimitExceeded **   
The quota for the resource has already been reached.  
For information about resource and stack limitations, see [Amazon CloudFormation quotas](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/cloudformation-limits.html) in the * Amazon CloudFormation User Guide*.  
HTTP Status Code: 400

 ** OperationIdAlreadyExists **   
The specified operation ID already exists.  
HTTP Status Code: 409

 ** OperationInProgress **   
Another operation is currently in progress for this StackSet. Only one operation can be performed for a stack set at a given time.  
HTTP Status Code: 409

 ** StackSetNotFound **   
The specified StackSet doesn't exist.  
HTTP Status Code: 404

 ** StaleRequest **   
Another operation has been performed on this StackSet since the specified operation was performed.  
HTTP Status Code: 409

## Examples
<a name="API_CreateStackInstances_Examples"></a>

### CreateStackInstances
<a name="API_CreateStackInstances_Example_1"></a>

This example illustrates one usage of CreateStackInstances.

#### Sample Request
<a name="API_CreateStackInstances_Example_1_Request"></a>

```
https://cloudformation.us-east-1.amazonaws.com/
 ?Action=CreateStackInstances
 &Version=2010-05-15
 &StackSetName=stack-set-example
 &Regions.member.1=us-east-1
 &Regions.member.2=us-west-2
 &OperationPreferences.MaxConcurrentCount=5
 &OperationPreferences.FailureTolerancePercentage=10
 &Accounts.member.1=[account]
 &Accounts.member.2=[account]
 &OperationId=c424b651-2fda-4d6f-a4f1-20c0example
 &X-Amz-Algorithm=AWS4-HMAC-SHA256
 &X-Amz-Credential=[Access key ID and scope]
 &X-Amz-Date=20170810T233349Z
 &X-Amz-SignedHeaders=content-type;host
 &X-Amz-Signature=[Signature]
```

#### Sample Response
<a name="API_CreateStackInstances_Example_1_Response"></a>

```
<CreateStackInstancesResponse xmlns="http://internal.amazon.com/coral/com.amazonaws.maestro.service.v20160713/">
  <CreateStackInstancesResult>
    <OperationId>c424b651-2fda-4d6f-a4f1-20c0fc62a6fe</OperationId>
  </CreateStackInstancesResult>
  <ResponseMetadata>
    <RequestId>97564c5e-813e-11e7-a9b2-5b163763e702</RequestId>
  </ResponseMetadata>
</CreateStackInstancesResponse>
```

## See Also
<a name="API_CreateStackInstances_SeeAlso"></a>

For more information about using this API in one of the language-specific Amazon SDKs, see the following:
+  [Amazon Command Line Interface V2](https://docs.amazonaws.cn/goto/cli2/cloudformation-2010-05-15/CreateStackInstances) 
+  [Amazon SDK for .NET V4](https://docs.amazonaws.cn/goto/DotNetSDKV4/cloudformation-2010-05-15/CreateStackInstances) 
+  [Amazon SDK for C\$1\$1](https://docs.amazonaws.cn/goto/SdkForCpp/cloudformation-2010-05-15/CreateStackInstances) 
+  [Amazon SDK for Go v2](https://docs.amazonaws.cn/goto/SdkForGoV2/cloudformation-2010-05-15/CreateStackInstances) 
+  [Amazon SDK for Java V2](https://docs.amazonaws.cn/goto/SdkForJavaV2/cloudformation-2010-05-15/CreateStackInstances) 
+  [Amazon SDK for JavaScript V3](https://docs.amazonaws.cn/goto/SdkForJavaScriptV3/cloudformation-2010-05-15/CreateStackInstances) 
+  [Amazon SDK for Kotlin](https://docs.amazonaws.cn/goto/SdkForKotlin/cloudformation-2010-05-15/CreateStackInstances) 
+  [Amazon SDK for PHP V3](https://docs.amazonaws.cn/goto/SdkForPHPV3/cloudformation-2010-05-15/CreateStackInstances) 
+  [Amazon SDK for Python](https://docs.amazonaws.cn/goto/boto3/cloudformation-2010-05-15/CreateStackInstances) 
+  [Amazon SDK for Ruby V3](https://docs.amazonaws.cn/goto/SdkForRubyV3/cloudformation-2010-05-15/CreateStackInstances)