fish-config/docs/manual/08-components-reference/03-c3-key-and-environment-overrides.md

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C3 — Key and Environment Overrides

These change fundamental shell behavior: how keys work, which pager opens, and what the prompt looks like. Disabling __fish_config_op_overrides removes all of them.

Override                  What it replaces or sets
───────────────────────────────────────────────────────────────────────────
Vi mode                   fish_vi_key_bindings replaces default Emacs mode
PATH setup                Prepends custom bin directories to the PATH
exit → smart_exit         exit wrapper that captures scrollback before closing
PAGER=ov                  ov used by git, man, and all $PAGER-aware tools
EDITOR=nvim               nvim fallback to vi for git commit, etc.
GPG_TTY                   Sets GPG_TTY to current terminal tty
MANPAGER=bat pipeline     man pages rendered with syntax highlighting
CDPATH=. ~/projects ~     bare dir names resolve against ~/projects and ~
Bang-bang system          ! and $ keys expand history; !^, !*, !-N, !?str?,
                          ^old^new abbreviations; six expand_bang_* helpers
Autopair                  ( [ { " ' auto-close to (), [], {}, "", ''
Puffer key intercepts     . ! $ * keys intercepted for smart expansion
Starship prompt           fish_prompt replaced by Starship + OSC 133 markers
Catppuccin colors         30+ fish_color_* variables set to Mocha palette
FZF_DEFAULT_OPTS          FZF themed to Catppuccin Mocha colors
Right prompt              fish_right_prompt: exit code (on failure) + dim timestamp; always rendered; Docker context added when starship+C3 active
DO_NOT_TRACK=1            Universal telemetry opt-out for tools and AI agents
DISABLE_TELEMETRY=1       Telemetry opt-out for telemetry-aware CLIs

The bang-bang system spans key_bindings.fish, abbr.fish, puffer.fish, and six expand_bang_*.fish functions. All are gated together — disabling C3 removes the entire bang-expansion system at once.

When C3 is disabled, exit falls back to builtin exit with no scrollback capture, no Kitty IPC, and no file I/O on exit. The scrollback capture block is independently controlled by C5 (see below).

Sub-categories

__fish_config_op_overrides sub-divides into four sub-categories, each with its own __fish_config_op_overrides_<slug> toggle:

key-bindings

Vi mode, autopair, puffer key intercepts, bang-bang history expansion, and smart_exit's plain-exit path.

environment

$PATH, $PAGER/$EDITOR/$GPG_TTY, and $CDPATH.

prompt

Starship, the right prompt, Catppuccin syntax/prompt colors, and FZF theming ($FZF_DEFAULT_OPTS) -- all driven by the same guard as a single unit, not independently toggleable from each other.

privacy

$DO_NOT_TRACK and $DISABLE_TELEMETRY environment variables for telemetry opt-out across CLI tools, runtimes, and AI agents.