This is the new *CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [AWS CloudFormation User Guide](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::SSM::Parameter
<a name="aws-resource-ssm-parameter"></a>

The `AWS::SSM::Parameter` resource creates an SSM parameter in AWS Systems Manager Parameter Store.

**Note**  
To create an SSM parameter, you must have the AWS Identity and Access Management (IAM) permissions `ssm:PutParameter` and `ssm:AddTagsToResource`. On stack creation, AWS CloudFormation adds the following three tags to the parameter: `aws:cloudformation:stack-name`, `aws:cloudformation:logical-id`, and `aws:cloudformation:stack-id`, in addition to any custom tags you specify.  
To add, update, or remove tags during stack update, you must have IAM permissions for both `ssm:AddTagsToResource` and `ssm:RemoveTagsFromResource`. For more information, see [Managing access using policies](https://docs.aws.amazon.com/systems-manager/latest/userguide/security-iam.html#security_iam_access-manage) in the *AWS Systems Manager User Guide*.

For information about valid values for parameters, see [About requirements and constraints for parameter names](https://docs.aws.amazon.com/systems-manager/latest/userguide/sysman-paramstore-su-create.html#sysman-parameter-name-constraints) in the *AWS Systems Manager User Guide* and [PutParameter](https://docs.aws.amazon.com/systems-manager/latest/APIReference/API_PutParameter.html) in the *AWS Systems Manager API Reference*.

## Syntax
<a name="aws-resource-ssm-parameter-syntax"></a>

To declare this entity in your CloudFormation template, use the following syntax:

### JSON
<a name="aws-resource-ssm-parameter-syntax.json"></a>

```
{
  "Type" : "AWS::SSM::Parameter",
  "Properties" : {
      "[AllowedPattern](#cfn-ssm-parameter-allowedpattern)" : String,
      "[DataType](#cfn-ssm-parameter-datatype)" : String,
      "[Description](#cfn-ssm-parameter-description)" : String,
      "[Name](#cfn-ssm-parameter-name)" : String,
      "[Policies](#cfn-ssm-parameter-policies)" : String,
      "[Tags](#cfn-ssm-parameter-tags)" : {Key: Value, ...},
      "[Tier](#cfn-ssm-parameter-tier)" : String,
      "[Type](#cfn-ssm-parameter-type)" : String,
      "[Value](#cfn-ssm-parameter-value)" : String
    }
}
```

### YAML
<a name="aws-resource-ssm-parameter-syntax.yaml"></a>

```
Type: AWS::SSM::Parameter
Properties:
  [AllowedPattern](#cfn-ssm-parameter-allowedpattern): String
  [DataType](#cfn-ssm-parameter-datatype): String
  [Description](#cfn-ssm-parameter-description): String
  [Name](#cfn-ssm-parameter-name): String
  [Policies](#cfn-ssm-parameter-policies): String
  [Tags](#cfn-ssm-parameter-tags): 
    Key: Value
  [Tier](#cfn-ssm-parameter-tier): String
  [Type](#cfn-ssm-parameter-type): String
  [Value](#cfn-ssm-parameter-value): String
```

## Properties
<a name="aws-resource-ssm-parameter-properties"></a>

`AllowedPattern`  <a name="cfn-ssm-parameter-allowedpattern"></a>
A regular expression used to validate the parameter value. For example, for `String` types with values restricted to numbers, you can specify the following: `AllowedPattern=^\d+$`  
*Required*: No  
*Type*: String  
*Minimum*: `0`  
*Maximum*: `1024`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`DataType`  <a name="cfn-ssm-parameter-datatype"></a>
The data type of the parameter, such as `text` or `aws:ec2:image`. The default is `text`.  
*Required*: No  
*Type*: String  
*Allowed values*: `text | aws:ec2:image`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Description`  <a name="cfn-ssm-parameter-description"></a>
Information about the parameter.  
*Required*: No  
*Type*: String  
*Minimum*: `0`  
*Maximum*: `1024`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Name`  <a name="cfn-ssm-parameter-name"></a>
The name of the parameter.  
The reported maximum length of 2048 characters for a parameter name includes 1037 characters that are reserved for internal use by Systems Manager. The maximum length for a parameter name that you specify is 1011 characters.  
This count of 1011 characters includes the characters in the ARN that precede the name you specify. This ARN length will vary depending on your partition and Region. For example, the following 45 characters count toward the 1011 character maximum for a parameter created in the US East (Ohio) Region: `arn:aws:ssm:us-east-2:111122223333:parameter/`.
*Required*: No  
*Type*: String  
*Minimum*: `1`  
*Maximum*: `2048`  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Policies`  <a name="cfn-ssm-parameter-policies"></a>
Information about the policies assigned to a parameter.  
[Assigning parameter policies](https://docs.aws.amazon.com/systems-manager/latest/userguide/parameter-store-policies.html) in the *AWS Systems Manager User Guide*.  
*Required*: No  
*Type*: String  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Tags`  <a name="cfn-ssm-parameter-tags"></a>
Optional metadata that you assign to a resource in the form of an arbitrary set of tags (key-value pairs). Tags enable you to categorize a resource in different ways, such as by purpose, owner, or environment. For example, you might want to tag a Systems Manager parameter to identify the type of resource to which it applies, the environment, or the type of configuration data referenced by the parameter.  
*Required*: No  
*Type*: Object of String  
*Pattern*: `^([\p{L}\p{Z}\p{N}_.:/=+\-@]*)$`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Tier`  <a name="cfn-ssm-parameter-tier"></a>
The parameter tier.  
*Required*: No  
*Type*: String  
*Allowed values*: `Standard | Advanced | Intelligent-Tiering`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Type`  <a name="cfn-ssm-parameter-type"></a>
The type of parameter.  
Parameters of type `SecureString` are not supported by AWS CloudFormation.
*Required*: Yes  
*Type*: String  
*Allowed values*: `String | StringList`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Value`  <a name="cfn-ssm-parameter-value"></a>
The parameter value.  
If type is `StringList`, the system returns a comma-separated string with no spaces between commas in the `Value` field.
*Required*: Yes  
*Type*: String  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

## Return values
<a name="aws-resource-ssm-parameter-return-values"></a>

### Ref
<a name="aws-resource-ssm-parameter-return-values-ref"></a>

When you pass the logical ID of this resource to the intrinsic `Ref` function, `Ref` returns the name of the SSM parameter. For example, `ssm-myparameter-ABCNPH3XCAO6`.

For more information about using the `Ref` function, see [https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html).

### Fn::GetAtt
<a name="aws-resource-ssm-parameter-return-values-fn--getatt"></a>

The `Fn::GetAtt` intrinsic function returns a value for a specified attribute of this type. The following are the available attributes and sample return values.

For more information about using the `Fn::GetAtt` intrinsic function, see [https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-getatt.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-getatt.html).

**Note**  
Due to eventual consistency of the underlying API, a `{ Fn::GetValue }` of an SSM Parameter that was just created may fail. Either avoid using `{ Fn::GetAtt }` on an SSM Parameter, or be aware that stack creation may sometimes fail and you will need to retry.

#### 
<a name="aws-resource-ssm-parameter-return-values-fn--getatt-fn--getatt"></a>

`Type`  <a name="Type-fn::getatt"></a>
Returns the type of the parameter. Valid values are `String` or `StringList`.

`Value`  <a name="Value-fn::getatt"></a>
Returns the value of the parameter.

## Examples
<a name="aws-resource-ssm-parameter--examples"></a>

**Topics**
+ [Create a String-type parameter](#aws-resource-ssm-parameter--examples--Create_a_String-type_parameter)
+ [Create a StringList-type parameter](#aws-resource-ssm-parameter--examples--Create_a_StringList-type_parameter)
+ [Create an advanced tier parameter and assign a policy](#aws-resource-ssm-parameter--examples--Create_an_advanced_tier_parameter_and_assign_a_policy)

### Create a String-type parameter
<a name="aws-resource-ssm-parameter--examples--Create_a_String-type_parameter"></a>

The following example creates a Systems Manager parameter named command with a `String` type and adds the tag key-value pair `"Environment":"Dev"`.

#### JSON
<a name="aws-resource-ssm-parameter--examples--Create_a_String-type_parameter--json"></a>

```
{
    "Resources": {
        "BasicParameter": {
            "Type": "AWS::SSM::Parameter",
            "Properties": {
                "Name": "command",
                "Type": "String",
                "Value": "date",
                "Description": "SSM Parameter for running date command.",
                "AllowedPattern": "^[a-zA-Z]{1,10}$",
                "Tags": {
                    "Environment": "DEV"
                }
            }
        }
    }
}
```

#### YAML
<a name="aws-resource-ssm-parameter--examples--Create_a_String-type_parameter--yaml"></a>

```
---
Resources:
  BasicParameter:
    Type: AWS::SSM::Parameter
    Properties:
      Name: command
      Type: String
      Value: date
      Description: SSM Parameter for running date command.
      AllowedPattern: "^[a-zA-Z]{1,10}$"
      Tags:
        Environment: DEV
```

### Create a StringList-type parameter
<a name="aws-resource-ssm-parameter--examples--Create_a_StringList-type_parameter"></a>

The following example creates a Systems Manager parameter named commands with a `StringList` type.

#### JSON
<a name="aws-resource-ssm-parameter--examples--Create_a_StringList-type_parameter--json"></a>

```
{
    "Resources": {
        "BasicParameter": {
            "Type": "AWS::SSM::Parameter",
            "Properties": {
                "Name": "commands",
                "Type": "StringList",
                "Value": "date,ls",
                "Description": "SSM Parameter of type StringList.",
                "AllowedPattern": "^[a-zA-Z]{1,10}$"
            }
        }
    }
}
```

#### YAML
<a name="aws-resource-ssm-parameter--examples--Create_a_StringList-type_parameter--yaml"></a>

```
---
Resources:
  BasicParameter:
    Type: AWS::SSM::Parameter
    Properties:
      Name: commands
      Type: StringList
      Value: date,ls
      Description: SSM parameter of type StringList.
      AllowedPattern: "^[a-zA-Z]{1,10}$"
```

### Create an advanced tier parameter and assign a policy
<a name="aws-resource-ssm-parameter--examples--Create_an_advanced_tier_parameter_and_assign_a_policy"></a>

The following example creates a Systems Manager advanced tier parameter named 'command' with a `String` type and a parameter policy.

#### JSON
<a name="aws-resource-ssm-parameter--examples--Create_an_advanced_tier_parameter_and_assign_a_policy--json"></a>

```
{
    "Resources": {
        "BasicParameter": {
            "Type": "AWS::SSM::Parameter",
            "Properties": {
                "Name": "command",
                "Type": "String",
                "Value": "date",
                "Tier": "Advanced",
                "Policies": "[{\"Type\":\"Expiration\",\"Version\":\"1.0\",\"Attributes\":{\"Timestamp\":\"2020-05-13T00:00:00.000Z\"}},{\"Type\":\"ExpirationNotification\",\"Version\":\"1.0\",\"Attributes\":{\"Before\":\"5\",\"Unit\":\"Days\"}},{\"Type\":\"NoChangeNotification\",\"Version\":\"1.0\",\"Attributes\":{\"After\":\"60\",\"Unit\":\"Days\"}}]",
                "Description": "SSM Parameter for running date command.",
                "AllowedPattern": "^[a-zA-Z]{1,10}$",
                "Tags": {
                    "Environment": "DEV"
                }
            }
        }
    }
}
```

#### YAML
<a name="aws-resource-ssm-parameter--examples--Create_an_advanced_tier_parameter_and_assign_a_policy--yaml"></a>

```
---
Resources:
  BasicParameter:
    Type: AWS::SSM::Parameter
    Properties:
      Name: command
      Type: String
      Value: date
      Tier: Advanced
      Policies: '[{"Type":"Expiration","Version":"1.0","Attributes":{"Timestamp":"2020-05-13T00:00:00.000Z"}},{"Type":"ExpirationNotification","Version":"1.0","Attributes":{"Before":"5","Unit":"Days"}},{"Type":"NoChangeNotification","Version":"1.0","Attributes":{"After":"60","Unit":"Days"}}]'
      Description: SSM parameter for running date command.
      AllowedPattern: "^[a-zA-Z]{1,10}$"
      Tags:
        Environment: DEV
```

## See also
<a name="aws-resource-ssm-parameter--seealso"></a>
+  [AWS Systems Manager Parameter Store](https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-parameter-store.html) 
+  [Managing parameters tiers](https://docs.aws.amazon.com/systems-manager/latest/userguide/parameter-store-advanced-parameters.html) 
+  [Assigning parameter policies](https://docs.aws.amazon.com/systems-manager/latest/userguide/parameter-store-policies.html)