A guide to setting up a custom command in Lazygit to generate git-commit messages with an LLM using LLM-Now

1 - Generate git commit messages in Lazygit.md

Never write a Lazygit commit message again!

This gist shows how to generate git-commit messages with LLM-Now in Lazygit.

Installation

1. Install LLM-Now using brew install swartzrock/tap/llm-now (macOS / Linux) or downloading a native executable from the releases page.
2. Set up an alias for a good provider and model in llm-now.
   1. I'm using haiku (Claude Haiku 4.5) here which works well.
   2. You can set up an alias by running llm-now --input "write a one-line poem about dogs" and selecting a local, cli, or cloud provider (with an API key env var). If you prefer to have llm-now securely store your api key run llm-now and choose Add or manage API keys… first.
3. Go to your lazygit config directory (cd $(lazygit --cd)) and copy the config.yml and llm-now-functions.sh files below into the directory (or merge with your existing config.yml file).
   1. Hint: set XDG_CONFIG_HOME=~/.config on macOS if you don't like working in the Application Support directory and don't want to change the hard-coded ~/.config/lazygit paths in the examples.
   2. Change the key to one that you'll remember.

Usage

In lazygit switch to the Files tab, press <space> to stage one or more files and press z to view and edit the generated git commit message then <enter> to commit the changes.

config.yml

# Include our llm_commit_message() function
os:
  shellFunctionsFile: ~/.config/lazygit/llm-now-functions.sh

customCommands:
  # Generate a commit message with llm-now
  - key: "z"
    context: files
    description: Show a custom git commit input with a generated commit message
    prompts:
      - type: input
        title: Commit summary [generated]
        key: Summary
        initialValue: >-
          {{ runCommand "/bin/zsh -c 'source ~/.config/lazygit/llm-now-functions.sh; llm_commit_message'" }}
    command: git commit --message {{.Form.Summary | quote}}
    loadingText: Committing staged changes
    output: log

llm-now-functions.sh

llm_commit_message() {
  local diff

  if ! diff=$(git diff --cached); then
    return 1
  fi

  if [ -z "$diff" ]; then
    printf 'llm_commit_message: no staged changes\n' >&2
    return 1
  fi

  {
    printf '%s\n\n' \
      'Write a Conventional Commit message for this staged diff. Return only the message.'
    printf '%s\n' "$diff"
  } | llm-now haiku
}