Metadata and Policy Default Values

Learn about the metadata file and how the policy_default_values are used.

Overview

The previous pages covered the core Azure assets in the library, and the various contructs - archetypes, overrides and architectures - that are used to collate those and use against a management group structure designed for governance.

This page will cover the remaining files in the library which are located in the root of the library structure:

alz_library_metadata.json: Metadata for library management - name, description, path and any dependencies on other libraries.
alz_policy_defaults_values.json: Enables a map of values to be defined and used across multiple policy assignments.

Metadata

There needs to be a single metadata file per library.


Folder
Filename	alz_library_metadata.json
Formats	JSON only
Examples	Azure Landing Zone library
	Sovereign Landing Zone library
	Example Sovereign Landing Zone country pack
Documentation	Metadata

Metadata schema

Metadata example #1: alz

This is the default metadata file for Azure Landing Zone.

{
  "$schema": "https://raw.githubusercontent.com/Azure/Azure-Landing-Zones-Library/main/schemas/library_metadata.json",
  "name": "ALZ",
  "display_name": "Azure Landing Zones",
  "description": "This library provides the reference set of Azure Landing Zones (ALZ) policies, archetypes, and management group architecture.",
  "path": "platform/alz"
}

The path in the repo is platform/alz
There are no dependencies.

Metadata example #2: alz_custom

This is the default metadata file for a local library in ./lib when stacked on top of the main Azure Landing Zone library.

{
  "$schema": "https://raw.githubusercontent.com/Azure/Azure-Landing-Zones-Library/main/schemas/library_metadata.json",
  "name": "local",
  "display_name": "ALZ Accelerator - Azure Verified Modules for ALZ Platform Landing Zone",
  "description": "This library allows overriding policies, archetypes, and management group architecture in the ALZ Accelerator.",
  "dependencies": [
    {
      "path": "platform/alz",
      "ref": "2026.01.0"
    }
  ]
}

There is a dependency on the platform/alz/2026.01.0 release.

Metadata example #3: slz

This is the default metadata file for Sovereign Landing Zone. This library is essentially a custom platform library stacked on top of the main Azure Landing Zone Library.

{
  "$schema": "https://raw.githubusercontent.com/Azure/Azure-Landing-Zones-Library/main/schemas/library_metadata.json",
  "name": "SLZ",
  "display_name": "Sovereign Landing Zone",
  "description": "This library provides the reference set of Sovereign Landing Zone (SLZ) policies, archetypes, and management group architecture.",
  "path": "platform/slz",
  "dependencies": [
    {
      "path": "platform/alz",
      "ref": "2026.01.0"
    }
  ]
}

The path in the repo is platform/slz
The Sovereign Landing Zone library is dependent on the platform/alz/2026.01.0 release.

Metadata example #4: slz_custom

This is the default metadata file for the local library in ./lib when stacked on top of the Sovereign Landing Zone library.

{
  "$schema": "https://raw.githubusercontent.com/Azure/Azure-Landing-Zones-Library/main/schemas/library_metadata.json",
  "name": "local",
  "display_name": "ALZ Accelerator - Azure Verified Modules for SLZ Platform Landing Zone",
  "description": "This library allows overriding policies, archetypes, and management group architecture in the ALZ Accelerator.",
  "dependencies": [
    {
      "path": "platform/slz",
      "ref": "2026.01.0"
    }
  ]
}

There is a dependency on the platform/slz/2025.10.1 Sovereign Landing Zone library release.
Remember that this is the one above, and therefore the dependency is recursively chained.
The full dependency chain is therefore ./lib > platform/slz/2025.10.1 > platform/alz/2026.01.0.

Policy Default Values

There can be an optional Policy Default Values file per library.


Folder
Filename	alz_policy_default_values.json
Formats	JSON or YAML
Examples	Azure Landing Zone library
	Sovereign Landing Zone library
	Example Sovereign Landing Zone country pack
Documentation	Policy Assignment Default Values

Default Policy Values schema

Metadata example #1: slz

This is the default_policy_values file for the Sovereign Landing Zone.

{
  "$schema": "https://raw.githubusercontent.com/Azure/Azure-Landing-Zones-Library/main/schemas/default_policy_values.json",
  "defaults": [
    {
      "default_name": "allowed_locations",
      "description": "Allowed Azure locations for Sovereign Landing Zone policies",
      "policy_assignments": [
        {
          "parameter_names": [
            "listOfAllowedLocations"
          ],
          "policy_assignment_name": "Enforce-Sovereign-Conf"
        },
        {
          "parameter_names": [
            "listOfAllowedLocations"
          ],
          "policy_assignment_name": "Enforce-Sovereign-Global"
        }
      ]
    }
  ]
}

The allowed_locations can be defined in the module’s policy_default_values map
It will be be consistently applied to multiple policy assignments.
Additional policy_default_values are pulled through from the dependencies, i.e. alz’s alz_policy_default_values.json.

Metadata example #2: nl_slz

This is the metadata file for the example country pack. It relies on the alz provider having `library_overwrite_enabled = true'.

{
  "$schema": "https://raw.githubusercontent.com/Azure/Azure-Landing-Zones-Library/main/schemas/default_policy_values.json",
  "defaults": [
    {
      "default_name": "allowed_locations",
      "description": "Allowed Azure locations for Sovereign Landing Zone policies",
      "policy_assignments": [
        {
          "parameter_names": [
            "listOfAllowedLocations"
          ],
          "policy_assignment_name": "Enforce-Sovereign-Conf"
        },
        {
          "parameter_names": [
            "listOfAllowedLocations"
          ],
          "policy_assignment_name": "Enforce-Sovereign-Global"
        },
        {
          "parameter_names": [
            "allowedLocations"
          ],
          "policy_assignment_name": "Deny-NL-Global"
        }
      ]
    }
  ]
}

The alz provider defines the defaults using the default_name as the key for a map.
If a duplicate is found then the last occurrence wins.
Here the local library’s metadata has dependencies on both the slz and the example nl_bio country pack.
The nl_bio definition is the last occurrence as it is later in the array.
The same applies to library definitions overwriting those in the dependent arrays.