Two capabilities
A shell system plus a terminal-native catalogue of shells, TUIs, CLIs, and integration hooks.
The problem
Shell setup and terminal-tool selection are usually duplicated per shell and per platform until they disagree.
Engineers managing fish, bash, and zsh across NixOS and Arch who want one environment declaration.
Why it matters
A focused part of the Corbet Nix suite
Adoption pattern
Takes over vendor-owned config files through a typed underlay instead of clobbering them.
System-provided binaries
Modules declare selection and hooks; installation stays with the host package source.
Evidence and limits
Inspect the claim, then the mechanism.
Bound to a revision-addressed public source; checks are declared in-tree and CNIX has not reproduced their results.
Project cosmos