Maester 3.0: a new test engine, and a heads-up for preview users
Maester 3.0 merges into main on Thursday, 8 October 2026 at 10:00 UTC (8 pm AEST). From that moment the preview build of Maester on the PowerShell Gallery is Maester 3.0, and 3.0 has breaking changes.
Your next scheduled run after the merge will pick up 3.0. The biggest change is that Maester 3.0 needs PowerShell 7.4 or later. Windows PowerShell 5.1 is no longer supported. We've worked hard to keep your custom tests (including Pester tests) working, but a rewrite this size will have rough edges.
You're on the preview build if your pipeline does any of these:
Install-Module Maester -AllowPrereleaseorUpdate-Module Maester -AllowPrereleasemaester_version: previewin the Maester GitHub Action
To stay on 2.x, install the release build instead: drop -AllowPrerelease, or pin the version with Install-Module Maester -RequiredVersion 2.3.0. In the GitHub Action, use maester_version: latest.
If you're using Maester interactively and want to see what's coming, the preview is exactly where we want you. Try it, and tell us what breaks.
