lumen is a command-line tool that uses AI to generate commit messages, summarise git diffs or past commits, and more without requiring an API key.

Features

• Generate commit message for staged changes
• Generate summary for changes in a git commit by providing its SHA-1
• Generate summary for changes in git diff (staged/unstaged)
• Fuzzy-search for the commit to generate a summary
• Free and unlimited - no API key required to work out of the box
• Pretty output formatting enabled by Markdown
• Supports multiple AI providers

Usage

Try lumen --help

To generate a commit message for staged changes

lumen draft

The commit message can be piped to other commands

# copy the commit message to clipboard (macos and linux, respectively)
lumen draft | pbcopy
lumen draft | xclip -selection clipboard

# open the commit message in your code editor
lumen draft | code -

# directly commit with the generated message
lumen draft | git commit -F -

The AI generates more meaningful commit messages when you provide context.

lumen draft
# Output: "feat(button.tsx): Change button color to blue"

lumen draft --context "match brand guidelines"
# Output: "feat(button.tsx): Update button color to align with brand identity"

To summarise a commit, pass in its SHA-1

lumen explain HEAD
lumen explain cc50651f

To use the interactive fuzzy-finder (requires: fzf)

lumen list

To generate a summary for the current git diff

lumen explain --diff
lumen explain --diff --staged

You can ask a question about the diff (or a commit) using --query

lumen explain --diff --query "how will this change affect performance?"
lumen explain HEAD~2 --query "how can this be improved?"

AI Provider can be configured by using CLI arguments or Environment variables.

-p, --provider <PROVIDER>  [env: LUMEN_AI_PROVIDER] [default: phind] [possible values: openai, phind, groq, claude, ollama]
-k, --api-key <API_KEY>    [env: LUMEN_API_KEY]
-m, --model <MODEL>        [env: LUMEN_AI_MODEL]

# eg: lumen -p="openai" -k="<your-api-key>" -m="gpt-4o" explain HEAD
# eg: lumen -p="openai" -k="<your-api-key>" -m="gpt-4o" draft
# eg: LUMEN_AI_PROVIDER="openai" LUMEN_API_KEY="<your-api-key>" LUMEN_AI_MODEL="gpt-4o" lumen list

Supported providers

Installation

Using Homebrew (MacOS and Linux)

brew tap jnsahaj/lumen
brew install --formula lumen

Using Cargo

[!IMPORTANT] cargo is a package manager for rust, and is installed automatically when you install rust. see installation guide

cargo install lumen

Prerequisites

1. git
2. fzf (optional): Required for lumen list command
3. mdcat (optional): Required for pretty output formatting