Building a Small Terminal Command Helper with an LLM

I regularly lose time to terminal muscle memory. I work across Windows and Unix-like shells, so I will remember the right command in the wrong environment, transpose a Git subcommand, or use a valid binary with an invalid subcommand. The fix is usually easy to find. The interruption is the costly part: stop, search, translate the answer back into the current shell, and try again. The idea is not new. There are projects that help with failed commands, as well as terminal-integrated LLMs such as aichat. However, I wanted something that does one thing well: fix commands in a seamless workflow powered by an LLM. I wanted a deliberately narrow tool: when a command fails, suggest the command I probably meant, let me inspect it, and run it only after confirmation. During a Fable promotion period, I used an LLM coding agent to see how far a well-scoped prompt could get me. With very little steering, it produced a usable Go prototype in roughly an hour. The project is now open source: nudge . The workflow I wanted The core interaction is intentionally small: Run a command as usual. If it fails, type fix (or bare nudge ) to get a suggested correction. Review it, then press Enter to run, e to edit it first, or n to cancel. The cheapest case is a plain typo, which never reaches a model at all: PS> git pshu git: 'pshu' is not a git command. See 'git --help'. PS> fix `git pshu` isn't a valid command. Did you mean: → git push (typo fix for `git pshu`) Run it? [Enter = yes / n = no / e = edit] The (typo fix for ...) label is the tool telling me it answered locally, in under 10 ms, without a network call. The cross-shell version of the same mistake is reaching for a binary that does not exist here. Because the binary is missing, the shell's command-not-found hook fires and I do not have to type anything at all: PS> printenv `printenv` isn't a valid command. Did you mean: → Get-ChildItem env: (list all environment variables) Run it? [Enter = yes / n = no / e = edit] The case that act