Blob Containers - Extend Immutability Policy

Service:

Storage Resource Provider

API Version:

2025-08-01

Extends the immutabilityPeriodSinceCreationInDays of a locked immutabilityPolicy. The only action allowed on a Locked policy will be this action. ETag in If-Match is required for this operation.

POST https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Storage/storageAccounts/{accountName}/blobServices/default/containers/{containerName}/immutabilityPolicies/default/extend?api-version=2025-08-01

URI Parameters

Name	In	Required	Type	Description
accountName	path	True	string minLength: 3 maxLength: 24 pattern: ^[a-z0-9]+$	The name of the storage account within the specified resource group. Storage account names must be between 3 and 24 characters in length and use numbers and lower-case letters only.
containerName	path	True	string minLength: 3 maxLength: 63	The name of the blob container within the specified storage account. Blob container names must be between 3 and 63 characters in length and use numbers, lower-case letters and dash (-) only. Every dash (-) character must be immediately preceded and followed by a letter or number.
resourceGroupName	path	True	string minLength: 1 maxLength: 90	The name of the resource group. The name is case insensitive.
subscriptionId	path	True	string (uuid)	The ID of the target subscription. The value must be an UUID.
api-version	query	True	string minLength: 1	The API version to use for this operation.

Request Header

Name	Required	Type	Description
If-Match	True	string	The entity state (ETag) version of the immutability policy to update must be returned to the server for all update operations. The ETag value must include the leading and trailing double quotes as returned by the service.

Request Body

Name	Type	Description
properties.allowProtectedAppendWrites	boolean	This property can only be changed for unlocked time-based retention policies. When enabled, new blocks can be written to an append blob while maintaining immutability protection and compliance. Only new blocks can be added and any existing blocks cannot be modified or deleted. This property cannot be changed with ExtendImmutabilityPolicy API.
properties.allowProtectedAppendWritesAll	boolean	This property can only be changed for unlocked time-based retention policies. When enabled, new blocks can be written to both 'Append and Bock Blobs' while maintaining immutability protection and compliance. Only new blocks can be added and any existing blocks cannot be modified or deleted. This property cannot be changed with ExtendImmutabilityPolicy API. The 'allowProtectedAppendWrites' and 'allowProtectedAppendWritesAll' properties are mutually exclusive.
properties.immutabilityPeriodSinceCreationInDays	integer (int32)	The immutability period for the blobs in the container since the policy creation, in days.

Responses

Name	Type	Description
200 OK	ImmutabilityPolicy	Azure operation completed successfully. Headers ETag: string
Other Status Codes	ErrorResponse	An unexpected error response.

Security

azure_auth

Azure Active Directory OAuth2 Flow.

Type: oauth2
Flow: implicit
Authorization URL: https://login.microsoftonline.com/common/oauth2/authorize

Scopes

Name	Description
user_impersonation	impersonate your user account

Examples

ExtendImmutabilityPolicy

Sample request

HTTP

POST https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/res6238/providers/Microsoft.Storage/storageAccounts/sto232/blobServices/default/containers/container5023/immutabilityPolicies/default/extend?api-version=2025-08-01


{
  "properties": {
    "immutabilityPeriodSinceCreationInDays": 100
  }
}

Sample response

Status code:

200

{
  "name": "default",
  "type": "Microsoft.Storage/storageAccounts/blobServices/containers/immutabilityPolicies",
  "etag": "\"8d57a8b2ff50332\"",
  "id": "/subscriptions/{subscription-id}/resourceGroups/res6238/providers/Microsoft.Storage/storageAccounts/sto232/blobServices/default/containers/container5023/immutabilityPolicies/default",
  "properties": {
    "immutabilityPeriodSinceCreationInDays": 100,
    "state": "Locked"
  }
}

Definitions

Name	Description
createdByType	The type of identity that created the resource.
ErrorResponse	An error response from the storage resource provider.
ErrorResponseBody	Error response body contract.
ImmutabilityPolicy	The ImmutabilityPolicy property of a blob container, including Id, resource name, resource type, Etag.
ImmutabilityPolicyState	The ImmutabilityPolicy state of a blob container, possible values include: Locked and Unlocked.
systemData	Metadata pertaining to creation and last modification of the resource.

createdByType

Enumeration

The type of identity that created the resource.

Value	Description
User
Application
ManagedIdentity
Key

ErrorResponse

Object

An error response from the storage resource provider.

Name	Type	Description
error	ErrorResponseBody	Azure Storage Resource Provider error response body.

ErrorResponseBody

Object

Error response body contract.

Name	Type	Description
code	string	An identifier for the error. Codes are invariant and are intended to be consumed programmatically.
message	string	A message describing the error, intended to be suitable for display in a user interface.

ImmutabilityPolicy

Object

The ImmutabilityPolicy property of a blob container, including Id, resource name, resource type, Etag.

Name	Type	Description
etag	string	Resource Etag.
id	string (arm-id)	Fully qualified resource ID for the resource. E.g. "/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/{resourceProviderNamespace}/{resourceType}/{resourceName}"
name	string	The name of the resource
properties.allowProtectedAppendWrites	boolean	This property can only be changed for unlocked time-based retention policies. When enabled, new blocks can be written to an append blob while maintaining immutability protection and compliance. Only new blocks can be added and any existing blocks cannot be modified or deleted. This property cannot be changed with ExtendImmutabilityPolicy API.
properties.allowProtectedAppendWritesAll	boolean	This property can only be changed for unlocked time-based retention policies. When enabled, new blocks can be written to both 'Append and Bock Blobs' while maintaining immutability protection and compliance. Only new blocks can be added and any existing blocks cannot be modified or deleted. This property cannot be changed with ExtendImmutabilityPolicy API. The 'allowProtectedAppendWrites' and 'allowProtectedAppendWritesAll' properties are mutually exclusive.
properties.immutabilityPeriodSinceCreationInDays	integer (int32)	The immutability period for the blobs in the container since the policy creation, in days.
properties.state	ImmutabilityPolicyState	The ImmutabilityPolicy state of a blob container, possible values include: Locked and Unlocked.
systemData	systemData	Azure Resource Manager metadata containing createdBy and modifiedBy information.
type	string	The type of the resource. E.g. "Microsoft.Compute/virtualMachines" or "Microsoft.Storage/storageAccounts"

ImmutabilityPolicyState

Enumeration

The ImmutabilityPolicy state of a blob container, possible values include: Locked and Unlocked.

Value	Description
Locked
Unlocked

systemData

Object

Metadata pertaining to creation and last modification of the resource.

Name	Type	Description
createdAt	string (date-time)	The timestamp of resource creation (UTC).
createdBy	string	The identity that created the resource.
createdByType	createdByType	The type of identity that created the resource.
lastModifiedAt	string (date-time)	The timestamp of resource last modification (UTC)
lastModifiedBy	string	The identity that last modified the resource.
lastModifiedByType	createdByType	The type of identity that last modified the resource.