SpecSync supports command line completion through the .NET dotnet-suggest tool (see changelog v5.0.0). The setup differs depending on how you use SpecSync.
SpecSync as global tool or downloaded executable
If you install SpecSync as a global .NET tool or use the downloaded executable, follow the official Microsoft guide for enabling tab completion: https://learn.microsoft.com/en-us/dotnet/standard/commandline/how-to-enable-tab-completion
SpecSync as local .NET tool
When SpecSync is installed as a local .NET tool, PowerShell needs an extra shim script to register completions for the dotnet specsync command. Use these steps after completing the Microsoft guide above:
Enable dotnet-suggest according to the Microsoft instructions.
Download the SpecSync shim script from https://content.specsolutions.eu/specsync/dotnet-tool-completion-shim.ps1 and place it next to the dotnet-suggest-shim.ps1 script referenced in your PowerShell profile.
Update your PowerShell profile (for example Microsoft.PowerShell_profile.ps1) to load both scripts (in this order):