How to write a PowerShell module manifest

After you've written your PowerShell module, you can add an optional module manifest that includes information about the module. For example, you can describe the author, specify files in the module (such as nested modules), run scripts to customize the user's environment, load type and formatting files, define system requirements, and limit the members that the module exports.

Creating a module manifest

A module manifest is a PowerShell data file (.psd1) that describes the contents of a module and determines how a module is processed. The manifest file is a text file that contains a hash table of keys and values. You link a manifest file to a module by naming the manifest the same as the module, and storing the manifest in the module's root directory.

For simple modules that contain only a single .psm1 or binary assembly, a module manifest is optional. But, the recommendation is to use a module manifest whenever possible, as they're useful to help you organize your code and maintain versioning information. And, a module manifest is required to export an assembly that is installed in the Global Assembly Cache. A module manifest is also required for modules that support the Updatable Help feature. Updatable Help uses the HelpInfoUri key in the module manifest to find the Help information (HelpInfo XML) file that contains the location of the updated help files for the module. For more information about Updatable Help, see Supporting Updatable Help.

To create and use a module manifest

1. The best practice to create a module manifest is to use the New-ModuleManifest cmdlet. You can use parameters to specify one or more of the manifest's default keys and values. The only requirement is to name the file. New-ModuleManifest creates a module manifest with your specified values, and includes the remaining keys and their default values. If you need to create multiple modules, use New-ModuleManifest to create a module manifest template that can be modified for your different modules. For an example of a default module manifest, see the Sample module manifest.

   New-ModuleManifest -Path C:\myModuleName.psd1 -ModuleVersion "2.0" -Author "YourNameHere"

   An alternative is to manually create the module manifest's hash table using the minimal information required, the ModuleVersion. You save the file with the same name as your module and use the .psd1 file extension. You can then edit the file and add the appropriate keys and values.

2. Add any additional elements that you want in the manifest file.

   To edit the manifest file, use any text editor you prefer. But, the manifest file is a script file that contains code, so you may wish to edit it in a scripting or development environment, such as Visual Studio Code. All elements of a manifest file are optional, except for the ModuleVersion number.

   For descriptions of the keys and values you can include in a module manifest, see the Module manifest elements table. For more information, see the parameter descriptions in the New-ModuleManifest cmdlet.

3. To address any scenarios that might not be covered by the base module manifest elements, you have the option to add additional code to your module manifest.

   For security concerns, PowerShell only runs a small subset of the available operations in a module manifest file. Generally, you can use the if statement, arithmetic and comparison operators, and the basic PowerShell data types.

4. After you've created your module manifest, you can test it to confirm that any paths described in the manifest are correct. To test your module manifest, use Test-ModuleManifest.

   Test-ModuleManifest myModuleName.psd1

5. Be sure that your module manifest is located in the top level of the directory that contains your module.

   When you copy your module onto a system and import it, PowerShell uses the module manifest to import your module.

6. Optionally, you can directly test your module manifest with a call to Import-Module by dot-sourcing the manifest itself.

   Import-Module .\myModuleName.psd1

Module manifest elements

The following table describes the elements you can include in a module manifest.

Sample module manifest

The following sample module manifest was created with New-ModuleManifest in PowerShell 7 and contains the default keys and values.

#
# Module manifest for module 'SampleModuleManifest'
#
# Generated by: User01
#
# Generated on: 10/15/2019
#

@{

# Script module or binary module file associated with this manifest.
# RootModule = ''

# Version number of this module.
ModuleVersion = '0.0.1'

# Supported PSEditions
# CompatiblePSEditions = @()

# ID used to uniquely identify this module
GUID = 'b632e90c-df3d-4340-9f6c-3b832646bf87'

# Author of this module
Author = 'User01'

# Company or vendor of this module
CompanyName = 'Unknown'

# Copyright statement for this module
Copyright = '(c) User01. All rights reserved.'

# Description of the functionality provided by this module
# Description = ''

# Minimum version of the PowerShell engine required by this module
# PowerShellVersion = ''

# Name of the PowerShell host required by this module
# PowerShellHostName = ''

# Minimum version of the PowerShell host required by this module
# PowerShellHostVersion = ''

# Minimum version of Microsoft .NET Framework required by this module. This prerequisite is valid for the PowerShell Desktop edition only.
# DotNetFrameworkVersion = ''

# Minimum version of the common language runtime (CLR) required by this module. This prerequisite is valid for the PowerShell Desktop edition only.
# CLRVersion = ''

# Processor architecture (None, X86, Amd64) required by this module
# ProcessorArchitecture = ''

# Modules that must be imported into the global environment prior to importing this module
# RequiredModules = @()

# Assemblies that must be loaded prior to importing this module
# RequiredAssemblies = @()

# Script files (.ps1) that are run in the caller's environment prior to importing this module.
# ScriptsToProcess = @()

# Type files (.ps1xml) to be loaded when importing this module
# TypesToProcess = @()

# Format files (.ps1xml) to be loaded when importing this module
# FormatsToProcess = @()

# Modules to import as nested modules of the module specified in RootModule/ModuleToProcess
# NestedModules = @()

# Functions to export from this module, for best performance, do not use wildcards and do not delete the entry, use an empty array if there are no functions to export.
FunctionsToExport = @()

# Cmdlets to export from this module, for best performance, do not use wildcards and do not delete the entry, use an empty array if there are no cmdlets to export.
CmdletsToExport = @()

# Variables to export from this module
VariablesToExport = '*'

# Aliases to export from this module, for best performance, do not use wildcards and do not delete the entry, use an empty array if there are no aliases to export.
AliasesToExport = @()

# DSC resources to export from this module
# DscResourcesToExport = @()

# List of all modules packaged with this module
# ModuleList = @()

# List of all files packaged with this module
# FileList = @()

# Private data to pass to the module specified in RootModule/ModuleToProcess. This may also contain a PSData hashtable with additional module metadata used by PowerShell.
PrivateData = @{

    PSData = @{

        # Tags applied to this module. These help with module discovery in online galleries.
        # Tags = @()

        # A URL to the license for this module.
        # LicenseUri = ''

        # A URL to the main website for this project.
        # ProjectUri = ''

        # A URL to an icon representing this module.
        # IconUri = ''

        # ReleaseNotes of this module
        # ReleaseNotes = ''

        # Prerelease string of this module
        # Prerelease = ''

        # Flag to indicate whether the module requires explicit user acceptance for install/update/save
        # RequireLicenseAcceptance = $false

        # External dependent modules of this module
        # ExternalModuleDependencies = @()

    } # End of PSData hashtable

} # End of PrivateData hashtable

# HelpInfo URI of this module
# HelpInfoURI = ''

# Default prefix for commands exported from this module. Override the default prefix using Import-Module -Prefix.
# DefaultCommandPrefix = ''

}

See also

• about_Comparison_Operators
• about_If
• Global Assembly Cache
• Import-Module
• New-ModuleManifest
• Test-ModuleManifest
• Update-ModuleManifest
• Writing a Windows PowerShell Module