Generate commit messages with OpenAI API

README.md

Generate commit messages with OpenAI API

This script automatically generates a commit message for staged changes in a git repository using OpenAI's API.

It tries to enforce the contributing guidelines for a good commit message.

Unfortunately, this doesn't always work. If you have ideas for a better prompt, please let me know!

Prerequisites

• OPENAI_API_KEY environment variable with a valid OpenAI API key
• jq
• curl

Usage

Put this script into your PATH and run it inside a git repository with staged changes:

$ gcm

gcm

#!/usr/bin/env bash

git rev-parse --is-inside-work-tree >/dev/null 2>&1 || {
	echo 'error: not inside a git repository' >&2
	exit 1
}

STAGED_DIFF=$(git diff --cached)
[ "$STAGED_DIFF" ] || {
	echo 'no staged changes found' >&2
	exit 0
}

(( $(echo "$STAGED_DIFF" | wc -l) > 1000 )) && {
	echo 'error: too many changes to upload' >&2
	exit 1
}

PROMPT=$(cat << EOF
Please generate a concise commit message using the following staged changes. The commit message must follow these strict formatting rules:

1. The first line MUST:
	- Be 50 characters or less.
	- Use the imperative mood.
	- NOT end with a period.

2. After the first line, there MUST be a blank line.

3. If further explanation is needed, include additional lines:
	- Each line MUST wrap at exactly 72 characters.
	- Do NOT exceed 72 characters per line.
	- Break sentences appropriately to ensure readability.

Now, analyze the following staged changes and generate a commit message that strictly adheres to these rules.

Staged changes:
${STAGED_DIFF}

IMPORTANT: Do not ignore these rules. The commit message must strictly follow them.
EOF
)

RESPONSE=$(curl -s -X POST 'https://api.openai.com/v1/chat/completions' \
	-H "Content-Type: application/json" \
	-H "Authorization: Bearer ${OPENAI_API_KEY}" \
	-d "$(jq -n \
		--arg model 'gpt-3.5-turbo' \
		--arg prompt "$PROMPT" \
		'{
			"model": $model,
			"messages": [
				{
					"role": "user",
					"content": $prompt
				}
			],
			"temperature": 0.7
		}'
	)"
) || exit $?

COMMIT_MESSAGE=$(echo "$RESPONSE" | \
	jq -r '.choices[0].message.content // empty' \
)

if [ -z "$COMMIT_MESSAGE" ] || [ "$COMMIT_MESSAGE" == 'null' ]; then
	echo "error: $RESPONSE" >&2
	exit 1
fi

git commit -e -m "$COMMIT_MESSAGE" "$@"