AI Powered Git Commits with Lazygit

Lazygit Gemini Configuration Guide

This guide explains how to configure Lazygit to use Google Gemini 3 Pro for generating commit messages on any device.

Prerequisites

Ensure you have the following installed on your system:

• curl
• jq (JSON processor)
• lazygit
• git

Step 1: Create the Helper Script

Create a script file at ~/.config/lazygit/gemini_commit_msg.sh.

#!/bin/bash
 
# Check if GEMINI_API_KEY is set
if [ -z "$GEMINI_API_KEY" ]; then
    echo "Error: GEMINI_API_KEY is not set."
    exit 1
fi
 
# Get the current branch name
BRANCH_NAME=$(git symbolic-ref --short HEAD 2>/dev/null)
if [ -z "$BRANCH_NAME" ]; then
    echo "Error: Not in a git repository or detached HEAD."
    exit 1
fi
 
# Extract ticket number (e.g., 123 from feature/123-foo)
TICKET_ID=$(echo "$BRANCH_NAME" | grep -oE '[0-9]+' | head -n 1)
 
# Get staged changes
DIFF=$(git diff --cached --diff-algorithm=minimal)
 
if [ -z "$DIFF" ]; then
    echo "Error: No staged changes found."
    exit 1
fi
 
# Construct the prompt
PROMPT="You are an expert developer. Write a commit message for the following git diff.
The commit message MUST follow the Conventional Commits format: <type>: <description>.
The type must be one of: feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert.
Keep the description concise (under 72 characters if possible).
Do NOT include the ticket number in your output, I will add it myself.
Do NOT output anything else, just the commit message line.
 
Diff:
$DIFF"
 
# Model Configuration
MODEL="gemini-3-pro-preview"
 
PAYLOAD=$(jq -n \
    --arg text "$PROMPT" \
    '{
        contents: [{
            parts: [{
                text: $text
            }]
        }]
    }')
 
# Call Gemini API
RESPONSE=$(curl -s -X POST \
    -H "Content-Type: application/json" \
    -d "$PAYLOAD" \
    "https://generativelanguage.googleapis.com/v1beta/models/$MODEL:generateContent?key=$GEMINI_API_KEY")
 
# Extract the text
COMMIT_MSG=$(echo "$RESPONSE" | jq -r '.candidates[0].content.parts[0].text' | tr -d '\n')
 
if [ -z "$COMMIT_MSG" ] || [ "$COMMIT_MSG" == "null" ]; then
    echo "Error: Failed to generate commit message."
    echo "Response: $RESPONSE"
    exit 1
fi
 
# Format the final message
if [ -n "$TICKET_ID" ]; then
    echo "(#$TICKET_ID) $COMMIT_MSG"
else
    echo "$COMMIT_MSG"
fi

Make the script executable:

chmod +x ~/.config/lazygit/gemini_commit_msg.sh

Step 2: Configure Lazygit

Add the following to your ~/.config/lazygit/config.yml file under the customCommands section:

customCommands:
  - key: 'C'
    context: 'files'
    description: 'Generate commit message with Gemini'
    command: 'git commit -m "$(bash ~/.config/lazygit/gemini_commit_msg.sh)" -e'
    subprocess: true

Step 3: Set Your API Key

Export your Gemini API key in your shell configuration file (e.g., ~/.bashrc, ~/.zshrc, or ~/.profile):

export GEMINI_API_KEY="your_actual_api_key_here"

Reload your shell or restart your terminal.

Usage

1. Open Lazygit in your repository.
2. Stage your changes.
3. Press C (Shift+C) in the Files panel.
4. Review the generated commit message in your editor.