Install-PowerShell

A cross‑platform GitHub Action that installs a specific PowerShell Core version—or the latest stable release—on any GitHub‑hosted runner (Linux, macOS, or Windows). The action automatically skips installation when the requested version is already present. Prerelease versions (e.g. 7.6.0-preview.6, 7.5.0-rc.1) are also supported.

Usage

Add the action to a job in your workflow file:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install PowerShell
        uses: PSModule/install-powershell@v1
        with:
          Version: 7.5.0

      - name: Run a PowerShell script
        shell: pwsh
        run: |
          Write-Host "Using PowerShell $($PSVersionTable.PSVersion)"

Installing a prerelease version

      - name: Install PowerShell Preview
        uses: PSModule/install-powershell@v1
        with:
          Version: 7.6.0-preview.6

Installing the latest prerelease

      - name: Install latest PowerShell Preview
        uses: PSModule/install-powershell@v1
        with:
          Prerelease: true

Inputs

Input	Required	Default	Description
Version	false	latest	Desired PowerShell Core version (e.g. 7.4.1, 7.6.0-preview.6). Use latest to install the newest stable release (or newest prerelease when Prerelease is true).
Prerelease	false	false	Install a prerelease version. When true and Version is latest, resolves to the latest prerelease. Similar to -Prerelease on Install-PSResource.

Secrets

This action does not require any secrets.

Outputs

This action does not generate any outputs.

How it works

• Version resolution If Version is set to latest (case‑insensitive), the action queries the GitHub API for the newest stable release tag in the PowerShell/PowerShell repository and substitutes that version. When Prerelease is true, it queries for the latest prerelease instead. Explicit prerelease version strings (e.g. 7.6.0-preview.6) are passed through directly.

• Skip logic Before installing, the action checks the current runner to see whether the requested version is already available (pwsh -Command $($PSVersionTable.PSVersion)). If it matches, the step ends immediately.

• Platform‑specific installers

  Runner OS	Install strategy
  Linux (Debian/Ubuntu‑based)	Uses APT if available; otherwise downloads the .deb asset directly from the release page and installs with dpkg.
  macOS	Prefers Homebrew Cask (brew install --cask powershell) and falls back to downloading the .pkg installer. ARCH detection (arm64 / x64) is automatic.
  Windows	Downloads the corresponding .msi package and installs silently with msiexec.

• Error handling The step fails with a clear error message if the requested version cannot be resolved or if the operating‑system distribution is unsupported (e.g., non‑APT Linux distros).