I'have just posted something like "request for comments" thing, so we could talk and make a proper solution. I've tried to use PowerShell in Windows, and it was pure pain: the tools, that are written in PS work fine, everything else (like git, InnoSetup, CMake, everything else...) just didn't have autocompletion at all. Maybe, some tools, like git do have shell plugins (like posh-git), but the problem in general still persists. Also, I am using Poetry and Werf utilities, that have built-in generator for autocomplete (bash, zsh and fish), but it doesn't work very well and the developers had to write it by themselves.

So, I've tried to make the spec as generic as possible, so it could support current compicated cases, like git (with its infinite number of commands and options), scp (with its remote file listing), some old Windows commands (like "format" for windows95 and so on).

Also, this format could be used with a single-pass recursive generator, because each usage pattern is just a JSON array and all its properties can be defined in-place. So, it would be okay to use it with languages, like C, that have no JSON serializer built-in.

I know what you mean. Go's spf13/cobra will soon have working zsh/bash/fish/powershell autocomplete generation!

https://github.com/spf13/cobra/pull/1070