Claude Code integration in Helix using Tmux

I am still trying out Helix as my primary editor on a daily basis. I have also started to try out Claude Code's CLI. I wanted a quick way to use Claude from within Helix, and to be able to point it to the currently open file or selected code. So I made a small script leveraging tmux that lets me do exactly that with Space + i.

The setup

A bash script at ~/.local/bin/helix-claude-tmux.sh:

#!/bin/bash
FILEPATH="$1"
SELECTION_START="$2"
SELECTION_END="$3"

# Try to find git root, otherwise use current directory
WORKDIR=$(git rev-parse --show-toplevel 2>/dev/null || pwd)

if [[ -n "$SELECTION_START" && -n "$SELECTION_END" && "$SELECTION_START" != "$SELECTION_END" ]]; then
    tmux command-prompt -p "Claude prompt:" \
        "split-pane -h -c '$WORKDIR' \"claude '%1 @$FILEPATH on lines $SELECTION_START to $SELECTION_END'\""
else
    tmux command-prompt -p "Claude prompt:" \
        "split-pane -h -c '$WORKDIR' \"claude '%1 @$FILEPATH'\""
fi

And two identical keybindings in ~/.config/helix/config.toml:

[keys.normal.space]
i = ":sh helix-claude-tmux.sh %{buffer_name} %{selection_line_start} %{selection_line_end}"

[keys.select.space]
i = ":sh helix-claude-tmux.sh %{buffer_name} %{selection_line_start} %{selection_line_end}"

Pretty straightforward. Hitting Space + i launches a Tmux command prompt where I can input my initial query to Claude. If any text is selected in the editor, the line range is passed to Claude, else just the prompt and the filepath is used. The script opens Claude in a horizontal tmux split pane with a prompt and the context. The pane is closed when I exit Claude.

Not perfect

While this is a pretty workable setup, it is still a litle less user friendly than the Code agent plugins in VS Code. As Claude edits the files on disk, the change is not reflected in Helix automatically, and requires a reload. Since Helix keeps the opened file in a buffer, I can end up with two sources of truth, and need to be a bit careful here. Usually this is not a problem, as I mostly use Claude for ideas and hints, and instruct it to not change the code, but rather give suggestions.